flange gasket

The Different Types of Gaskets for Flanges (Soft, SWG, RTJ, Kammprofile, Jacketed): Use & Selection

flange gasket

The Different Types of Gaskets for Flanges (Soft, SWG, RTJ, Kammprofile, Jacketed): Use & Selection

The article outlines the five primary types of flange gaskets used in the oil and gas industry: non-asbestos, spiral wound, ring joint (including R, RX, and BX styles for RTJ flange faces), Kammprofile, and jacketed gaskets. Each gasket type is detailed in terms of its application scope, with non-asbestos gaskets being suited for low-pressure, low-temperature, and non-critical uses, while spiral wound gaskets cater to applications involving higher temperatures and pressures. Ring joint gaskets are specified for RTJ flange faces and come in styles R, RX, and BX, indicating their design and sealing capabilities. Kammprofile and jacketed gaskets are also discussed, highlighting their construction and suitability for specific sealing environments. Additionally, the article reviews the dimensional standards set forth by ASME B16.20 and ASME B16.21, the materials used for each gasket type, and provides guidance on selecting the appropriate gasket for various piping applications.

GASKETS FOR FLANGES

WHAT ARE GASKETS FOR FLANGES?

A flange gasket is a type of sealing component designed to fit between two sections of pipe that are flanged together.

Flanges are external or internal ridges that are used for strength or for the attachment of a component, like a pipe. The primary purpose of a flange gasket is to prevent leaks by providing a sealed interface between the two flange faces, ensuring no fluids or gases can escape from the flanged joint.

gasket seal 1
Gasket to Seal Flanges (Main & Companion)

Key Characteristics of Flange Gaskets:

  • Material Composition: Flange gaskets are made from a wide range of materials, including rubber, non-asbestos synthetic fibers, metal, silicone, PTFE (polytetrafluoroethylene), and graphite, among others. The choice of material depends on the application, including factors such as the type of fluid being sealed, operating temperature, pressure conditions, and chemical compatibility.

  • Shape and Size: They are typically circular to match the shape of the flanges, with bolt holes aligned to match the flange pattern. Gaskets come in various sizes and thicknesses to suit different flange standards and specifications, such as those outlined by ASME B16.5 or EN 1092-1.

  • Types of Flange Gaskets: There are several types of flange gaskets, including flat or sheet gaskets, which are simple and used in low-pressure environments; spiral-wound gaskets, which are suitable for higher-pressure and higher-temperature applications; ring-type joints, which are used in high-pressure situations; cam profile and metal-jacketed gaskets, which offer robust sealing for a wide range of temperatures and pressures. All these types are reviewed in detail in this article.

Gaskets Function and Application:

  • Sealing Function: The primary role of a flange gasket is to create a tight seal between two flange faces, preventing the escape of fluids and maintaining the integrity of the piping system.

  • Versatility: Flange gaskets are used across various industries, including oil and gas, chemical processing, power generation, and water treatment. They are critical components in pipelines, tanks, and vessels that transport or store liquids and gases.

  • Pressure and Temperature Resistance: Different gasket materials and designs can withstand various levels of pressure and temperature, making it crucial to select the right gasket type based on specific operational conditions.

In summary, flange gaskets are essential components in piping systems, ensuring leak-free connections between flanged pipe sections. Their effectiveness in sealing joints makes them indispensable in maintaining operational efficiency, safety, and environmental compliance across many industries.

WHY ARE GASKETS IMPORTANT IN PIPING SYSTEMS?

Gaskets for flanges play a crucial role in the integrity, safety, and efficiency of piping systems across various industries, including oil and gas, chemical processing, power generation, and water treatment. These components are essential for creating tight, leak-proof seals between flange connections, ensuring the safe and effective transport of fluids and gases. Below are detailed reasons why gaskets for flanges are important:

1. Preventing Leaks:

  • Safety and Environmental Protection: Gaskets prevent hazardous materials, such as chemicals or hydrocarbons, from leaking into the environment, thus protecting ecosystems and reducing the risk of accidents and health hazards.
  • Operational Integrity: By ensuring a leak-proof seal, gaskets maintain the pressure and flow characteristics within the system, crucial for process efficiency and reliability.

2. Withstanding Harsh Conditions:

  • Pressure and Temperature Tolerance: Gaskets are designed to withstand the operational pressures and temperatures of the system they are part of. High-performance materials can tolerate extreme conditions without degradation, maintaining a seal under varying or extreme conditions.
  • Chemical Compatibility: The materials used for gaskets are selected based on their resistance to the chemicals they will be exposed to, preventing material breakdown and ensuring long-term sealing performance.

3. Facilitating System Maintenance and Flexibility:

  • Ease of Maintenance: Flange gaskets allow for the disassembly and reassembly of pipe sections without damage. This is crucial for routine maintenance, inspections, or system modifications.
  • System Adaptability: The use of gaskets in flange connections enables the connection of dissimilar materials and the easy addition or removal of sections of the piping system, providing flexibility in system design and expansion.

4. Reducing Costs:

  • Leak Prevention: By preventing leaks, gaskets save costs associated with lost products, environmental fines, and cleanup efforts.
  • Maintenance Costs: The ability to reuse flanges and only replace gaskets during maintenance reduces the need for expensive component replacements.

5. Improving Performance:

  • Sealing Efficiency: Proper gasket selection and installation improve the overall efficiency of the piping system by ensuring optimal pressure conditions are maintained, which can enhance the performance of pumps and other system components.
  • Vibration Damping: Some gasket materials can dampen vibrations within the system, reducing noise and wear on components.

6. Customization and Versatility:

  • Wide Range of Materials: Gaskets are available in various materials, including rubber, PTFE, graphite, and metals, allowing for customization based on specific application needs.
  • Design Versatility: Gaskets can be designed and cut to fit any flange size and shape, making them versatile for standard and custom applications.

SPECIFICATIONS FOR GASKETS (ASME/API)

ASME (American Society of Mechanical Engineers) and API (American Petroleum Institute) provide specifications and standards for gaskets used in piping systems, pressure vessels, and related equipment, particularly in the oil, gas, and petrochemical industries. These specifications ensure gaskets perform effectively under various operational conditions, contributing to the safety, reliability, and efficiency of industrial processes.

Here’s an overview of some key ASME and API specifications relevant to gaskets:

ASME Specifications for Gaskets

  • ASME B16.20: This standard covers metallic gaskets for pipe flanges in the raised face, flat face, and ring joint configurations. It includes spiral wound gaskets, metal-jacketed gaskets, and ring-type joint gaskets (RTJ). ASME B16.20 specifies dimensions, materials, and application guidelines.

  • ASME B16.21: This specification details non-metallic flat gaskets for pipe flanges. It covers materials such as compressed fiber sheets, PTFE, and flexible graphite, providing dimensions and tolerances for various flange sizes and pressure classes.

API Specifications for Gaskets

  • API 6A: This specification, titled “Specification for Wellhead and Christmas Tree Equipment,” includes requirements for ring-type joint gaskets used in high-pressure and high-temperature oil and gas production environments. It defines dimensions, materials, and performance criteria for RTJ gaskets.

  • API 622: Titled “Type Testing of Process Valve Packing for Fugitive Emissions,” this standard, while focused on valve packing, indirectly affects gasket selection and usage in ensuring low emission levels in valves. It sets testing requirements to evaluate the performance of packing materials under various conditions.

  • API 600: While primarily focused on steel gate valves for the petroleum and natural gas industries, API 600 also references gasket dimensions and materials compatible with the valve design standards, highlighting the importance of gasket selection in valve integrity and performance.

Let’s now delve into the different types of gaskets for flanges used in the oil & gas and processing industries.

NON-ASBESTOS GASKETS (“SOFT”)

WHAT ARE NON-ASBESTOS GASKETS?

Non-asbestos gaskets are, in general terms, sealing devices used between two surfaces to prevent leaks of liquids or gases in various applications, especially in piping (in the context of flanged joints), machinery, and equipment.

The terms, “flat-cut gaskets”, “die-cut gaskets”, “compressed sheet gaskets”, “compressed-fiber gaskets” and “asbestos-free gaskets” are synonyms to define this first type of gaskets for flanges, and can be interchanged.

die cut gaskets e1548871379503
Asbestos-Free Gaskets

Non-asbestos gaskets are the simplest type of gasket for flanges and are produced by cutting graphite, organic, or inorganic non-asbestos sheets into a round-gasket shape (generally, with water jet cutting machines). The two main types of non-asbestos gaskets for flanges are the “full face” (FF) for FF flanges and the “flat ring” type for raised face flanges (RF). These two key sub-types are shown in the image below:

Full face and ring gasket

In piping systems, non-asbestos gaskets are used in low-pressure, low-temperature, and non-critical applications, i.e. they represent an entry-level alternative.

The ASME B16.21 specification covers non-asbestos sheet gaskets for flanges and flanged joints (types, sheet materials, dimensions, dimensional tolerances, and marking requirements).

Non-asbestos gaskets are designed to replace asbestos-containing gaskets, which were widely used in the past due to their durability, heat resistance, and sealing capabilities but have since been phased out (in the 70s) due to health risks associated with asbestos exposure, including respiratory issues and serious illnesses like asbestosis and mesothelioma.

Composition and Features:

Non-asbestos gaskets are made from a combination of synthetic fibers, such as Aramid (a strong and heat-resistant synthetic fiber), fiberglass, and elastomeric materials like nitrile rubber, EPDM, or Neoprene. These components are mixed and bound together to create a sheet material that can be cut and shaped into gaskets. The specific composition of a non-asbestos gasket can vary depending on the manufacturer and the intended application, allowing for customization to meet different sealing requirements.

Advantages:

  • Health and Safety: The primary advantage of non-asbestos gaskets is their safety; they do not pose the health risks associated with asbestos fibers.
  • Versatility: These gaskets can be engineered to suit a wide range of applications, offering resistance to various chemicals, temperatures, and pressures.
  • Durability: Non-asbestos gaskets are designed to be durable and withstand harsh operational conditions, similar to their asbestos counterparts.
  • Environmental Compliance: Using non-asbestos materials aligns with global regulations and standards aimed at reducing health risks and environmental impact.

Applications:

Non-asbestos gaskets are used in a variety of settings, including:

  • Piping Systems: For sealing flanges in water, gas, and chemical pipelines.
  • Automotive Industry: In engines, transmissions, and other systems requiring durable seals.
  • Industrial Machinery: For sealing joints in pumps, valves, and other equipment.
  • HVAC Systems: In heating, ventilation, and air conditioning units to prevent leaks.

Selection Considerations:

When selecting a non-asbestos gasket, consider factors such as:

  • Operating Temperature and Pressure: Ensure the gasket material can withstand the specific conditions of the application.
  • Chemical Compatibility: The gasket material should resist the chemicals it will be exposed to, preventing degradation and failure.
  • Compliance and Certifications: Choose gaskets that meet relevant industry standards and certifications for quality and performance.

COMMON MATERIALS FOR SOFT GASKETS

Materials for soft gaskets

Introduction

Non-asbestos gaskets for flanges are made from a variety of synthetic materials that provide similar or superior performance to asbestos gaskets without health risks. These materials are selected for their ability to withstand various industrial conditions, including different temperatures, pressures, and chemical exposures.

The most common materials used to manufacture compressed-fiber gaskets are Aramid fibers (Kevlar), Teflon (PTFE), graphite, glass fibers, elastomers, and Neoprene mixed with a multitude of binder materials (the most common binder is NBR, i.e. Buna-N):

  • Aramid NBR binder
  • Carbon graphite reinforced
  • Glass reinforced (steam service gasket)
  • PTFE bi-axially oriented (silica filler)
  • SBR (styrene-butadiene)
  • CR-chloroprene (Neoprene)
  • EPDM gasket (ethylene propylene)
  • Fluorocarbon (Viton)
  • Graphite
  • BUNA-n-rubber (nitrile, NBR gasket)
  • Chlorosulfonated polyethylene (Hypalon gasket)
  • Aramid + SBR binder (premium type gasket)
  • Graphite + ss316/316l insert
  • PTFE biaxially oriented (with hollow glass microsphere) blue
  • PTFE biaxially oriented (pigment-free)-gray
  • expanded PTFE gasket
  • PTFE joint sealant
  • PTFE envelope slit type
  • PTFE envelope milled type
  • PTFE envelope formed type
  • MICA sheet
  • Ceramic fiber

Key Non-Asbestos Materials

The key features of the key classes of materials listed above are:

Aramid Fiber:

  • Characteristics: Aramid fibers are known for their strength, heat resistance, and durability. They are often used as a replacements for asbestos.
  • Applications: Ideal for use in environments with high mechanical stress and where thermal stability is required.

PTFE (Polytetrafluoroethylene):

  • Characteristics: PTFE is highly resistant to chemicals and has a very low coefficient of friction. It is stable across a wide range of temperatures.
  • Applications: Suitable for applications involving aggressive chemicals, such as strong acids and bases, or where cleanliness and non-contamination are critical, such as in the food and pharmaceutical industries.

Graphite:

  • Characteristics: Graphite gaskets offer excellent thermal stability, high compressibility, and good resistance to most chemicals.
  • Applications: Used in high-temperature applications, such as exhaust systems, steam services, and where fire safety is a concern.

Elastomeric Compounds:

  • Nitrile Rubber (NBR): Resistant to oils, fuels, and some chemicals. Used in applications involving oil and hydrocarbons.
  • Ethylene Propylene Diene Monomer (EPDM): Has excellent resistance to weathering, ozone, UV, and many chemicals. It’s used in water and steam services.
  • Neoprene: Offers good resistance to oils, chemicals, and flame. Suitable for a wide range of applications, including refrigerants and moderate acids.

Fiberglass:

  • Characteristics: Fiberglass has good thermal resistance and tensile strength. It is less commonly used alone but often incorporated with other materials to enhance thermal stability.
  • Applications: Suitable for high-temperature applications, often in combination with other materials like PTFE or graphite.

Composite Materials:

  • Characteristics: Combinations of different synthetic fibers, fillers, and rubber binders are used to create composite materials that can be tailored to specific application requirements.
  • Applications: Versatile use across a wide range of conditions, depending on the specific composition of the gasket material.

Non-asbestos gaskets can also be coated with graphite, for non-stick and steam resistance, mixed with PTFE for excellent chemical resistance, or with EPDM for potable water applications.

DIMENSIONS

Soft Gaskets for ASME B16.5 Flanges

Non-asbestos gaskets dimensions (for ASME B16.5 FF flanges), in millimeters

soft gaskets sizes

NPSd1
(ID)
d2 (GASKET OUTSIDE DIAMETER)
Class 150Class 300Class 400Class 600Class 900
1/2214854545464
3/4275767676770
1336773737379
1¼427683838389
1½488695959598
260105111111111143
2½73124130130130.2165
389137149149149168
3½102162165162162
4114175181178194206
5141197216213241248
6168222251248267289
8219279308305321359
10273340362359400435
12324410422419457498
14356451486483492521
16406514540537565575
18457549597594613638
20508606654648683699
24610718775768791838

All values in millimeters

Soft Gaskets for ASME B16.47 – Series A Flanges

Non-asbestos gaskets dimensions (for ASME B16.47 series A flanges), in millimeters

soft gaskets sizes

NPSd1 (ID)d2 (GASKET OUTSIDE DIAMETER)
Class 150Class 300Class 400Class 600
26660775835832867
28711832899892914
30762883953946972
32813940100610031022
34864991105710541073
369141048111811181130
389651111105410731105
4010161162111411271156
4210671219116511781219
4411181276121912321270
4611681327127312891327
4812191384132413461391
5012701435137814031448
5213211492142914541499
5413721549149215181556
5614221607154315681613
5814731664159416191664
6015241715164516831721

All values in millimeters

Soft Gaskets for ASME B16.47 – Series B Flanges

Non-asbestos gaskets dimensions (for ASME B16.47 series B flanges), in millimeters

soft gaskets sizes

NPSd1 (ID)d2 (GASKET OUTSIDE DIAMETER)
Class 150Class 300Class 400Class 600
26660725772746765
28711776826800819
30762827886857879
32813881940911933
34864935994962997
36914987104810221048
3896510451099
40101610951149
42106711461200
44111811971251
46116812561318
48121913071368
50127013571419
52132114081470
54137214641530
56142215141594
58147315801656
60152416301705

All values in millimeters. Dimensional tolerances:

  • For outside diameter NPS 12 and smaller: +0 / -1.5 mm.; NPS 14 and larger: +0 / -3.0 mm.
  • For inside diameter NPS 12 and smaller: ± 1.5 mm; NPS 14 and larger: ± 3.0 mm

SPIRAL WOUND GASKET (“SWG”)

WHAT ARE SPIRAL-WOUND GASKETS?

A Spiral wound gasket for flanges features a core metal sealing element filled with graphite, PTFE, ceramic fibers, and, or non-asbestos fibers (fillers). For this reason, spiral wound gaskets are classified as “semi-metallic” gaskets.

Spiral wound gasket

The metal component of the spiral wound gasket provides strength to the seal, whereas the fillers enhance the gasket’s conformability and resilience. Inner and outer rings can be added to the core sealing element to facilitate the installation and enhance the pressure rating. Spiral wound gaskets with graphite fillers are the most commonly used type.

Spiral wound gasket are designed to withstand, better than other types of flange gaskets such as the soft type, the mechanical stress generated by high temperature and high-pressure applications. Spiral wound gaskets are widely used in the oil and gas industry, chemical processing, power generation, and other sectors where sealing integrity under challenging conditions is critical. They are particularly valued in applications involving:

  • Fluctuating pressures and temperatures.
  • High-pressure and high-temperature environments.
  • Joints requiring high purity or where aggressive chemicals are present.

The structure of SWG gaskets consist of:

  • Metallic Outer Ring: Often included as a centering ring, it provides radial strength and centers the gasket within the flange. It also serves as a compression stop and helps protect the gasket’s inner winding.
  • Metallic Windings: Typically made from stainless steel or other alloys, these windings provide structural strength and ensure the gasket’s ability to withstand high pressures and temperatures.
  • Filler Material: Sandwiched between the metal windings, common fillers include flexible graphite, PTFE (Polytetrafluoroethylene), or non-asbestos materials. The filler material is selected based on chemical compatibility with the media being sealed and the operational conditions.
  • Inner Ring (optional): Used in some designs to prevent inward buckling of the gasket and protect the windings from corrosive or erosive media.

Flexitallic USA introduced spiral wound gaskets in the petrochemical industry back in 1912 to cope with an increasing demand for leak-proof seals in applications with higher and higher (and fluctuating) temperatures and pressures. Other reputable spiral wound gasket manufacturers are Garlock and Lamons. Since then, a myriad of manufacturers of SWG has emerged, also in developing countries as India and China.

The diameter of a spiral wound gasket may range between a few mm and up to 5.000 mm, and the typical thicknesses of spiral wound gaskets ranges from 3.2, 4.5, 6.4, to 7.2 mm.

A Spiral wound gasket may be ordered in different shapes, such as oblong, rectangular, oval, pear, and diamond.

ASME B16.20 is the spiral wound gasket specification.

The round type is, of course, the standard shape for the raised face (RF), male-and-female (M&F), and tongue-and-groove flanges (T&G) for petrochemical applications.

TYPES OF SWG

A few different types of spiral wound gaskets exist, depending on two main construction parameters:

  • the number of rings (center, outer and inner rings)
  • the materials of the inner and the outer ring of the gasket
  • the type of filler material used for the core-ring

A generally accepted taxonomy for SWG comprises the following base-types:

1. Basic Type:

The simplest form of spiral wound gasket, consisting only of the metal spiral and the filler material. It lacks any metal reinforcement on the inner and outer diameters. This type is suitable for tongue and groove flanges and some male-female flange arrangements.

2. With Inner Ring:

This type includes an inner metal ring which adds structural support, preventing the gasket’s spiral wound portion from buckling inwardly. The inner ring also serves as a heat and corrosion barrier, protecting the gasket’s integrity and improving its sealing capability. It’s particularly useful for raised face, male-female, and tongue-and-groove flanges in applications dealing with corrosive media, ensuring the filler material does not get in direct contact with the process fluid.

3. With Outer Ring (Centering Ring):

Incorporates an outer metal ring that serves as a centering device for the gasket on the flange face. It also acts as a compression stop, providing additional radial strength and preventing over-compression of the gasket. This design is widely used with raised face flanges, helping to align the gasket during installation and operation.

4. With Inner and Outer Rings:

Combines the benefits of both inner and outer rings. The inner ring provides protection against inward buckling and media erosion, while the outer ring centers the gasket on the flange and acts as a compression limit. This type is ideal for standard raised face and flat face flanges, offering enhanced structural integrity and alignment.

5. Windings With Metal Strip:

Some spiral wound gaskets feature a metal strip wound together with the filler material, enhancing their strength and making them suitable for extremely high-pressure applications. This type is less common but utilized in specific scenarios where additional mechanical strength is required.

6. Specialty Gaskets:

There are also specialty spiral wound gaskets designed for specific applications, such as those with layers of different metals or fillers to address unique chemical resistance, temperature, or pressure requirements. These gaskets are custom-engineered for particular operational conditions or regulatory compliance needs.

Based on this basic classification, it is therefore common to see in the catalogs of gaskets manufacturers nomenclatures like:

  • Type 00: Spiral Wound Gasket without rings: they are used for tongue and groove, male and female flanges.
  • Type 01: Spiral Wound Gasket with inner ring: they are used for male and female or special flange types.
  • Type 10: Spiral Wound Gasket with outer ring: they are used for raised face flanges.
  • Type 101: Spiral Wound Gasket with inner and outer rings: they are used for raised face flanges.
  • Special Section: Spiral Wound Gasket with special rings: they are used for special flanges and special usage.

spiral wound gaskets types

Each manufacturer, of course, uses specific codes to designate different types of spiral wound gasket in production, but the typical designs are recurring regardless of the producer.

The image shows how the different spiral wound gasket types are used for flanged joints in piping applications:

types of SW gaskets

SWG MATERIALS

Section of spiral wound gasket

Spiral Winding Materials

The sealing element of a spiral wound gasket is produced by interleaving plies of alternating metal winding strips combined with a filler material. The formed metal strip is the key sealing element of this type of semi-metallic gasket.

The most common winding materials are:

  • SS 304L
  • SS 316L
  • SS 321
  • Titanium
  • Nickel
  • Nickel alloys
  • Duplex

Filler Materials

Filler materials are used to enhance the conformability and resilience of a spiral wound gasket. The most used filler material is graphite, however, other filler materials may be used depending on the application:

  • Graphite
  • PTFE
  • Ceramic fibers
  • Non-asbestos

Inner and Outer Rings Materials

The inner and outer rings of a spiral wound gasket may be the same material as the winding core or a different one.

Solid inner rings are required by the ASME B16.20 specification for flanges with pressure rating 900# NPS 24 and larger, 1500# NPS 12 and larger, pressure class 2500#, NPS 4 and larger.

The inner ring improves the pressure rating of the spiral wound gasket, as it provides additional compression to the flanged joint and provides a heat and corrosion barrier protecting the gasket windings and the flanges from erosion.

Mechanical Properties by Material

Spiral Wound Gasket Material
(Commercial Name)
DIN
SPECIFICATION
DIN
MATERIAL NR.
AISI &
UNS
B.S &
ASTM
HARDNESS
HV 10
TEMPERATURE RANGE in C°VOLUMETRIC MASS [G/CM3]
MIN.MAX.
Soft Iron (Armco)–1.1003––90 – 100-605007.85
Steel (LCS)RSt.37.21.0038––100 – 130-405007.85
Stainless Steel 304X5CrNi 181.4301304304S15/16/31130 – 180-2505507,9
Stainless Steel 304 LX2CrNi 1891.4306304L304S11130 – 190-2505507,9
Stainless Steel 309X15CrNiMo 20121.4828309309S24130 – 190-10010007,9
Stainless Steel 316X5CrNiMo 18101.4401316316S31/33130 – 180-1005507,9
Stainless Steel 316 LX2CrNiMo 18101.4404316L316S11/13130 – 190-1005507,9
Stainless Steel 316 TiX10CrNiMoTi 18101.4571316Ti320S31130 – 190-1005507,8
Stainless Steel 321X10CrNiTi 1891.4541321321S12/49/87130 – 190-2505507,9
Stainless Steel 347X10CrNiNb 1891.4550347347S31130 – 190-2505507,9
Nickel 200Ni 99.22,4066NO22003072-76 NA1190 – 120-2506008,9
Monel 400NiCu 30 Fe2.4360NO44003072-76 NA13110 – 150-1256008,8
Inconel 600NiCr 15 Fe2.4816NO66003072-76 NA14120 – 180-1009508,4
Incoloy 800X10NiCrAITi 32201.4876NO88003072-76 NA15140 – 220-1008508,4
Incoloy 825NiCR 21 Mo2.4858NO88253072-76 NA 16120 – 180-1004508,14
Hastelloy B2NMo 282.4617N10665–170 – 230-2004509,2
Hastelloy C276‘NiMo 16Cr15W2.4819N10276–170 – 230-2004508.9
TitaniumTi 99,83.7025––110 – 140-2505004,5
 

COLOR CODING FOR SWG

Spiral wound gaskets featuring various combinations of winding and filler materials can be readily identified through standardized color codes. Each material combination is marked with distinct colors: the primary color represents the winding material, while stripes signal the type of filler used.

Spiral Wound Gaskets Color Coding

  • Metallic winding materials: the metallic winding material is designated by a solid color identification around the outside edge of the centering, as shown in the image below
  • Non-metallic filler color coding: the gasket filler materials are designated by several stripes placed at equal distances around the edge of the centering ring

 

Spiral Wound Gasket Color Coding

Color Codes for Winding Materials

Metallic Winding Material for Spiral Wound GasketAbbreviated Winding
Material Name
Color Code
Carbon steel CRSSilver
304 SS 304Yellow
304 L SS 304 LNo color
309 SS 309No color
316 L SS 316 LGreen
347 SS 347Blue
321 SS 321Turquoise
Monel 400 MONOrange
Nickel 200 NIRed
Titanium TIPurple
Hastelloy B HAST BBrown
Hastelloy C HAST CBeige

Color Codes for Filler Materials

Polytetrafluoroethylene PTFEWhite stripe
Mica-graphite Manufacturer’s designationPink stripe
Flexible graphite F.G.Gray stripe
Ceramic CERLight green stripe
Inconel 600 Inconel 600Gold
Inconel 625 Inconel 625Gold
Incoloy 800 Incoloy 800 H / HTWhite
Incoloy 825 Incoloy 825White

ASME MARKING REQUIREMENTS FOR SWG

ASME (American Society of Mechanical Engineers) provides specific marking requirements for spiral wound gaskets to ensure proper identification and application in accordance with the ASME B16.20 standard, which covers metallic gaskets for pipe flanges. These marking requirements are essential for the correct selection and use of gaskets in piping systems, promoting safety and operational efficiency. According to ASME B16.20, the following information must be marked directly on the spiral wound gasket or on a tag attached to the gasket:

1. Manufacturer’s Name or Trademark:

This helps in identifying the manufacturer of the gasket, ensuring traceability and accountability.

2. Gasket Type:

The specific type of spiral wound gasket indicates its construction and design features.

3. Nominal Pipe Size and Pressure Class:

These indicate the size and pressure rating of the flanges with which the gasket is intended to be used, ensuring compatibility with the piping system.

4. Material Identification:

  • Winding Material: The material used for the winding (e.g., stainless steel, Monel) must be identified, often through a standard abbreviation.
  • Filler Material: The type of filler material (e.g., flexible graphite, PTFE) used between the windings must also be specified.
  • Inner and Outer Ring Material (if applicable): For gaskets that include inner and/or outer rings, the material of these components should be identified.

5. ASME B16.20 Designation:

This confirms that the gasket has been manufactured under the ASME B16.20 standard.

Additional Markings (Optional or As Applicable):

  • Special Features: Any special features or modifications to the standard design may be indicated.
  • Heat Code or Lot Number: Providing traceability back to the manufacturing batch, which can be crucial for quality control and in the event of identifying material properties.

The illustration shows the typical marking of spiral wound gaskets:

Spiral wound gasket marking

DIMENSIONS OF SWG

Size of SWG Class 150

Dimensions of class 150 spiral wound gaskets for ASME B16.5 (in mm.)

Spiral wound gaskets dimensions
Spiral wound gasket dimensions
NPSInner RingSealing ElementOuter Ring
Inside Diameter (d1)Inside Diameter (d2)Outside Diameter(d3)Outside Diameter (d4)
1/214.219.131.847.8
3/420.625.439.657.2
126.931.847.866.8
1¼38.147.860.576.2
1½44.554.169.985.9
255.669.985.9104.9
2½66.582.698.6124
381101.6120.7136.7
4106.4127149.4174.8
5131.8155.7177.8196.9
6157.2182.6209.6222.3
8215.9233.4263.7279.4
10268.2287.3317.5339.9
12317.5339.9374.7409.7
14349.3371.6406.4450.9
16400.1422.4463.6514.4
18449.3474.7527.1549.4
20500.1525.5577.9606.6
24603.3628.7685.8717.6

NOTES: • All dimensions are in millimeters • Spiral Wound gasket with Inner – and Outer ring • d1 = Inside diameter Inner ring. • d2 = Inside diameter sealing element when no Inner ring is used. • d3 = Outside diameter of sealing element. • d4 = Outside diameter of an Outer ring
The thickness of the inner and outer ring: 2.97 mm – 3.33 mm. • Thickness sealing element: 4.45 mm. • Tolerance Outside diameter for NPS 1/2 through NPS 8 is ± 0.8 mm; for NPS 10 through NPS 24 tolerance is + 1.5 mm – 0.8 mm. • There is no class 400 flanges NPS 1/2 thru NPS 3 (use Class 600), class 900 flanges NPS 1/2 thru NPS 2½ (use Class 1500), or class 2500 flanges NPS 14 or larger. 

Size of SWG Class 300

Dimensions of class 300 spiral wound gaskets for ASME B16.5 (in mm.)

Spiral wound gaskets dimensions
Dimensions of spiral wound gaskets
NPSInner RingSealing ElementOuter Ring
Inside Diameter (d1)Inside Diameter (d2)Outside Diameter (d3)Outside Diameter (d4)
1/214.219.131.854.1
3/420.625.439.666.8
126.931.847.873.2
1¼38.147.860.582.6
1½44.554.169.995.3
255.669.985.9111.3
2½66.582.698.6130.3
381101.6120.7149.4
4106.4127149.4181.1
5131.8155.7177.8215.9
6157.2182.6209.6251
8215.9233.4263.7308.1
10268.2287.3317.5362
12317.5339.9374.7422.4
14349.3371.6406.4485.9
16400.1422.4463.6539.8
18449.3474.7527.1596.9
20500.1525.6577.9654.1
24603.3628.7685.8774.7

NOTES: • All dimensions are in millimeters • Spiral Wound gasket with Inner – and Outer ring • d1 = Inside diameter Inner ring. • d2 = Inside diameter sealing element when no Inner ring is used. • d3 = Outside diameter of sealing element. • d4 = Outside diameter of an Outer ring
The thickness of the inner and outer ring: 2.97 mm – 3.33 mm. • Thickness sealing element: 4.45 mm. • Tolerance Outside diameter for NPS 1/2 through NPS 8 is ± 0.8 mm; for NPS 10 through NPS 24 tolerance is + 1.5 mm – 0.8 mm. • There is no class 400 flanges NPS 1/2 thru NPS 3 (use Class 600), class 900 flanges NPS 1/2 thru NPS 2½ (use Class 1500), or class 2500 flanges NPS 14 or larger. 

Size of SWG Class 400

Dimensions of class 400 spiral wound gaskets for ASME B16.5 (in mm.)

Spiral wound gaskets dimensions
Dimensions of spiral wound gasket
NPSInner RingSealing ElementOuter Ring
Inside Diameter (d1)Inside Diameter (d2)Outside Diameter (d3)Outside Diameter (d4)
1/214.219.131.854.1
3/420.625.439.666.8
126.931.847.873.2
1¼38.147.860.582.6
1½44.554.169.995.3
255.669.985.9111.3
2½66.582.698.6130.3
381101.6120.7149.4
4102.6120.7149.4177.8
5128.3147.6177.8212.9
6154.9174.8209.6247.7
8205.7225.6263.7304.8
10255.3274.6317.5358.9
12307.3327.2374.7419.1
14342.9362406.4482.6
16389.9412.8463.6536.7
18438.2469.9527.1593.9
20489520.7577.9647.7
24590.6628.7685.8768.4

NOTES: • All dimensions are in millimeters • Spiral Wound gasket with Inner – and Outer ring • d1 = Inside diameter Inner ring. • d2 = Inside diameter sealing element when no Inner ring is used. • d3 = Outside diameter of sealing element. • d4 = Outside diameter of an Outer ring
The thickness of the inner and outer ring: 2.97 mm – 3.33 mm. • Thickness sealing element: 4.45 mm. • Tolerance Outside diameter for NPS 1/2 through NPS 8 is ± 0.8 mm; for NPS 10 through NPS 24 tolerance is + 1.5 mm – 0.8 mm. • There is no class 400 flanges NPS 1/2 thru NPS 3 (use Class 600), class 900 flanges NPS 1/2 thru NPS 2½ (use Class 1500), or class 2500 flanges NPS 14 or larger. 

Size of SWG Class 600

Dimensions of class 600 spiral wound gaskets for ASME B16.5 (in mm.)

Spiral wound gaskets dimensions
Dimensions of spiral wound gaskets
NPSInner RingSealing ElementOuter Ring
Inside Diameter (d1)Inside Diameter (d2)Outside Diameter (d3)Outside Diameter (d4)
1/214.219.131.854.1
3/420.625.439.666.8
126.931.847.873.2
1¼38.147.860.582.6
1½44.554.169.995.3
255.669.985.9111.3
2½66.582.698.6130.3
378.7101.6120.7149.4
4102.6120.7149.4193.8
5128.3147.6177.8241.3
6154.9174.8209.6266.7
8205.7225.6263.7320.8
10255.3274.6317.5400.1
12307.3327.2374.7457.2
14342.9362406.4492.3
16389.9412.8463.6565.2
18438.2469.9527.1612.9
20489520.7577.9682.8
24590.6628.7685.8790.7

NOTES: • All dimensions are in millimeters • Spiral Wound gasket with Inner – and Outer ring • d1 = Inside diameter Inner ring. • d2 = Inside diameter sealing element when no Inner ring is used. • d3 = Outside diameter of sealing element. • d4 = Outside diameter of an Outer ring
The thickness of the inner and outer ring: 2.97 mm – 3.33 mm. • Thickness sealing element: 4.45 mm. • Tolerance Outside diameter for NPS 1/2 through NPS 8 is ± 0.8 mm; for NPS 10 through NPS 24 tolerance is + 1.5 mm – 0.8 mm. • There is no class 400 flanges NPS 1/2 thru NPS 3 (use Class 600), class 900 flanges NPS 1/2 thru NPS 2½ (use Class 1500), or class 2500 flanges NPS 14 or larger. 

Size of SWG Class 900

Dimensions of class 900 spiral wound gaskets for ASME B16.5 (in mm.)

Spiral wound gaskets dimensions
Dimensions of spiral wound gaskets
NPSInner RingSealing ElementOuter Ring
Inside Diameter (d1) Inside Diameter (d2) Outside Diameter(d3) Outside Diameter (d4)
1/214.219.131.863.5
3/420.625.439.669.9
126.931.847.879.5
1¼33.339.660.588.9
1½41.447.869.998.6
252.358.785.9143
2½63.569.998.6165.1
378.795.3120.7168.4
4102.6120.7149.4206.5
5128.3147.6177.8247.7
6154.9174.8209.6289.1
8196.9222.3257.3358.9
10246.1276.4311.2435.1
12292.1323.9368.3498.6
14320.8355.6400.1520.7
16374.7412.8457.2574.8
18425.5463.6520.7638.3
20482.6520.7571.5698.5
24590.6628.7679.5838.2

NOTES: • All dimensions are in millimeters • Spiral Wound gasket with Inner – and Outer ring • d1 = Inside diameter Inner ring. • d2 = Inside diameter sealing element when no Inner ring is used. • d3 = Outside diameter of sealing element. • d4 = Outside diameter of an Outer ring
The thickness of the inner and outer ring: 2.97 mm – 3.33 mm. • Thickness sealing element: 4.45 mm. • Tolerance Outside diameter for NPS 1/2 through NPS 8 is ± 0.8 mm; for NPS 10 through NPS 24 tolerance is + 1.5 mm – 0.8 mm. • There is no class 400 flanges NPS 1/2 thru NPS 3 (use Class 600), class 900 flanges NPS 1/2 thru NPS 2½ (use Class 1500), or class 2500 flanges NPS 14 or larger. 

Size of SWG Class 1500

Dimensions of class 1500 spiral wound gaskets for ASME B16.5 (in mm.)

Spiral wound gaskets dimensions
Dimensions of spiral wound gaskets
NPSInner RingSealing ElementOuter Ring
Inside Diameter (d1)  Inside Diameter (d2) Outside Diameter(d3) Outside Diameter (d4)
1/214.219.131.863.5
3/420.625.439.669.9
126.931.847.879.5
1¼33.339.660.588.9
1½41.447.869.998.6
252.358.785.9143
2½63.569.998.6165.1
378.792.2120.7174.8
497.8117.6149.4209.6
5124.5143177.8254
6147.3171.5209.6282.7
8196.9215.9257.3352.6
10246.1266.7311.2435.1
12292.1323.9368.3520.7
14320.8362400.1577.9
16374.7406.4457.2641.4
18425.5463.6520.7704.9
20476.3514.4571.5755.7
24577.9616679.5901.7
 
NOTES: • All dimensions are in millimeters • Spiral Wound gasket with Inner – and Outer ring • d1 = Inside diameter Inner ring. • d2 = Inside diameter sealing element when no Inner ring is used. • d3 = Outside diameter of sealing element. • d4 = Outside diameter of an Outer ring

The thickness of the inner and outer ring: 2.97 mm – 3.33 mm. • Thickness sealing element: 4.45 mm. • Tolerance Outside diameter for NPS 1/2 through NPS 8 is ± 0.8 mm; for NPS 10 through NPS 24 tolerance is + 1.5 mm – 0.8 mm. • There is no class 400 flanges NPS 1/2 thru NPS 3 (use Class 600), class 900 flanges NPS 1/2 thru NPS 2½ (use Class 1500), or class 2500 flanges NPS 14 or larger. 

Size of SWG Class 2500

Dimensions of class 2500 spiral wound gaskets for ASME B16.5 (in mm.)

Spiral wound gaskets dimensions
Dimensions of spiral wound gaskets
NPSInner RingSealing ElementOuter Ring
 Inside Diameter (d1) Inside Diameter (d2) Outside Diameter(d3) Outside Diameter (d4)
1/214.219.131.869.9
3/420.625.439.676.2
126.931.847.885.9
1¼33.339.660.5104.9
1½41.447.869.9117.6
252.358.785.9146
2½63.569.998.6168.4
378.792.2120.7196.9
497.8117.6149.4235
5124.5143177.8279.4
6147.3171.5209.6317.5
8196.9215.9257.3387.4
10246.1270311.2476.3
12292.1317.5368.3549.4

NOTES: • All dimensions are in millimeters • Spiral Wound gasket with Inner – and Outer ring • d1 = Inside diameter Inner ring. • d2 = Inside diameter sealing element when no Inner ring is used. • d3 = Outside diameter of sealing element. • d4 = Outside diameter of an Outer ring
The thickness of the inner and outer ring: 2.97 mm – 3.33 mm. • Thickness sealing element: 4.45 mm. • Tolerance Outside diameter for NPS 1/2 through NPS 8 is ± 0.8 mm; for NPS 10 through NPS 24 tolerance is + 1.5 mm – 0.8 mm. • There is no class 400 flanges NPS 1/2 thru NPS 3 (use Class 600), class 900 flanges NPS 1/2 thru NPS 2½ (use Class 1500), or class 2500 flanges NPS 14 or larger. 

RING JOINT GASKETS STYLE R, RX, BX (“RTJ”)

WHAT IS A RING JOINT GASKET?

A ring joint gasket is a type of metal gasket designed for high-pressure and high-temperature applications, commonly used in the oil, gas, petrochemical, and offshore industries. These gaskets are specifically engineered to seal flanged connections that are subjected to extreme conditions where conventional gaskets might fail. Ring joint gaskets are typically used with ring-type joint (RTJ) flanges, which have grooves cut into their faces to accommodate the gasket.

Construction and Materials:

  • Shape and Design: Ring joint gaskets come in various shapes, including oval and octagonal cross-sections, which are the most common. There are also BX and RX styles designed for specific types of RTJ flanges and pressures.
  • Materials: They are usually made from durable metals such as soft iron, stainless steel, Hastelloy, Inconel, and Monel. The choice of material depends on the application, considering factors like temperature, pressure, and chemical compatibility.

A Ring Joint Gasket (RTJ) provides a strong and durable metal-to-metal seal between two mating RTJ flanges. As the flanges are bolted, the softer material of the ring joint gasket is “squeezed” into the flanges grooves (made of a harder material) and seals the connection very tightly. RTJ gaskets are available in three styles, R (oval, octagonal), RX, and BX.

Ring joint gaskets (RTJ) ensure a long-lasting and strong seal for flanges, valves, piping spools, and vessels at high pressure and temperatures (which are typical conditions for many petrochemical processes).

Features and Benefits:

  • High Integrity Seal: The metal-to-metal contact between the gasket and the flange grooves provides a high-integrity seal that can withstand significant pressure variations and vibrations.
  • Temperature and Pressure Resistance: Ring joint gaskets are capable of withstanding extreme temperatures and pressures, making them suitable for challenging environments.
  • Reusability: Certain materials allow ring joint gaskets to be reused, provided they are not damaged and are correctly reinstalled.
RTJ gaskets are available in different designs (called “styles”) and dimensions, as illustrated in the picture below (BX, R, and BX).

Ring Joint Gasket Styles

RTJ GASKETS TYPES

R Type Ring Joint Gasket (Oval and Octagonal)

“Style R” is the most common RTJ gasket type. R-type ring joint gaskets are available in oval or octagonal cross-sections and manufactured according to API 6A and ASME B16.20 to suit API 6B and ASME/ANSI B16.5 flanges.

This type of RTJ gasket is machined to tight manufacturing tolerances to ensure correct installation with standard ASME B16.5 and API 6B ring joint faced flanges. “R style” oval and octagonal RTJ gaskets can seal pressures up to 6.250 psi by ASME B16.20 and up to 5.000 psi according to the API 6A pressure ratings.

Type R RTJ gaskets are frequently used for valve covers.

Style RX RTJ Gasket

The RX-type RTJ gasket is manufactured according to API 6A and ASME B16.20 to suit API 6B and ASME/ANSI B16.5 flanges.

The RX is a pressure-energized version of the R octagonal gasket and fits the R-type flat-bottomed groove.

The RX has an increased height and utilizes the internal system pressure to energize and improve the seal as internal pressure increases.

Some RX sizes have a pressure relief hole to equalize pressure on both sides of the sealing faces.

Style BX RTJ Gasket

The BX-type RTJ gaskets are manufactured according to API 6A and are suitable for use in high-pressure API 6BX flanges.

The gaskets form a metal-to-metal seal on assembly and the efficiency improves as internal pressure increases.

All BX sizes have a pressure relief hole to equalize pressure across sealing faces.

RTJ GASKET MATERIALS

The material of RTJ gaskets shall match the material of the flange but must have a lower hardness: this is to ensure that the gasket, and not the flange, gets plastically deformed within the groove of the flange as the two mating flanges are bolted together.

In case a harder material for the ring-type joint is used, the groove of the flange would be damaged as the flanges are tightened (the hardness values for ring joint gaskets are given below).

Types of Materials for Ring Joint Gaskets

RTJ GASKET MATERIALRING IDASTM GRADEDIN GRADEWKSTOFF NUMBERAISI
GRADE
BS
GRADE
OTHER SPECS
Soft IronD  1.1003 / 1.0335  Aramco / StW24
LCSS  1.1003 / 1.0335  Aramco / StW24
CS360 LTCS360LTA516 Gr70     
41404140UNS G4140042CrMo41.72254140  
F5F5UNS K4254412CrMo1951.7362  5Cr 1/2Mo
SS304S304S30400X5CrNi 18 91.4301304304S15 
SS304LS304LS30403X2CrNi 18 91.4306304L304SS12 
SS309S309S30900X15CrNiSi20121.4828309309S24 
SS310S310S31008XX15CrNiSi25201.4841310310S24 
SS316S316S31600X5CrNiMo18 101.4401316316S16 
SS316LS316LS31603X2CrNiMo18 101.4404316L316S11/316S12 
SS316L UREAS316UGS31603X2CrNiMo 18 14 31.4435   
SS316TiS316TiS31635X10CrNiMoTi18101.4571316Ti320S31/320S17 
SS321S321S32100X10CrNiTi18 91.4541321321S12 
SS347S347S34700X10CrNiNb 18 91.455347347S51 
SS410S410S41000X10Cr131.4006410410S21 
Monel 400Monel400N04400NiCu30Fe2.436   
Inconel 600INC600N06600NiCr15Fe2.4816   
Inconel 625INC625N06625NiCr22Mo9Nb2.4856   
Inconel 718INC718N07718     
Incoloy 800INC800N08800X5NiCrAlTi31-201.4958   
Incoloy 800HINC800HN08810 1.4958   
Incoloy 825INC825N08825NiCr21Mo2.4858   
904L904LN08904X1NiCrMoCu25-20-51.4539   
F51F51S31803X2CrNiMoN22-5-31.4462  2205 /Duplex
F53F53S32750X2CrNiMoN25-7-41.441   
F55F55S32760X2CrNiMoCuWN 25 7 41.4501  Zeron 100
F60F60S32205    Duplex
TitaniumTiR 50400 3.7035   
17-4PH17-4PHS17400 1.4542  630
S254S254S31254X1CrNiMoCuN20-18-71.4547  F44 / 6Mo
C276C276N10276NiMo16Cr15W2.4819  Hastelloy
Alloy 28Alloy28N08028X1 NiCrMoCuN 31 27 41.4563  SANICRO 28

Mechanical Properties Ring Joint Gaskets Materials

 Maximum Hardness of RTJ Gaskets 

RTJ Gasket Material

BrinellHRBID

Soft Iron-S

9056D

Low Carbon Steel

12068S

4 – 6% Chrome
1/2% Moly

13072F5

SS 304 Stainless Steel

16083S304

SS 316 Stainless Steel

16083S316

SS 347 Stainless Steel

16083S347

SS 410 Stainless Steel

17096S410

RTJ GASKET DIMENSIONS (ASME B16.20)

Style R Ring Joint Gaskets Dimensions (for ASME B16.5 flanges)

Ring joint gasket sizes

RTJ GASKET RING NUMBERDiameter PWidth AHeightOct COct R1NPS / CLASS
Oval BOct H
R 1134.146.3511.29.74.321.51/2
300 / 600
R 1239.77.9514.212.75.231.51/2
900 / 1500
R 1342.887.9514.212.75.231.53/4
300 / 600
1/2
2500
R 1444.457.9514.212.75.231.53/4
900 / 1500
R 1547.637.9514.212.75.231.51
150
R 1650.87.9514.212.75.231.51
300 / 1500
3/4
2500
R 1757.157.9514.212.75.231.51¼
150
R 1860.337.9514.212.75.231.51¼
300 / 1500
1
2500
R 1965.17.9514.212.75.231.51½
150
R 2068.287.9514.212.75.231.51½
300 / 1500
R 2172.2411.1317.5167.751.51¼
2500
R 2282.557.9514.212.75.231.52
150
R 2382.5511.1317.5167.751.52
300 600
1½
2500
R 2495.2511.1317.5167.751.52
900 / 1500
R 25101.67.9514.212.75.231.52½
150
R 26101.611.1317.5167.751.52½
300/ 600
2
2500
R 27107.9511.1317.5167.751.52½
900 / 1500
R 28111.1312.719.117.58.661.52½
2500
R 29114.37.9514.212.75.231.53
150
R 30
*
117.4811.1317.5167.751.53
300 / 600
R 31123.8311.1317.5167.751.53
300 / 900
R 3212712.719.117.58.661.53
2500
R 33131.787.9514.212.75.231.53½
150
R 34131.7811.1317.5167.751.53½
300 / 600
R 35136.5311.1317.5167.751.53
1500
R 36149.237.9514.212.75.231.54
150
R 37149.2311.1317.5167.751.54
300 / 900
R 38157.1815.8822.420.610.491.54
2500
R 39161.9311.1317.5167.751.54
1500
R 40171.457.9514.212.75.231.55
150
R 41180.9811.1317.5167.751.55
300 / 900
R 42190.519.0525.423.912.321.55
2500
R 43193.687.9514.212.75.231.56
150
R 44193.6811.1317.5167.751.55
1500
R 45211.1511.1317.5167.751.56
300 / 900
R 46211.1512.719.117.58.661.56
1500
R 47228.619.0525.423.912.321.56
2500
R 48247.657.9514.212.75.231.58
150
R 49269.8811.1317.5167.751.58
300 / 900
R 50269.8815.8822.420.610.491.58
1500
R 51279.422.2328.726.914.811.58
2500
R 52304.87.9514.212.75.231.510
150
R 53323.8511.1317.5167.751.510
300 900
R 54323.8515.8822.420.610.491.510
1500
R 55342.928.5836.635.119.812.310
2500
R 563817.9514.212.75.231.512
150
R 5738111.1317.5167.751.512
300 900
R 5838122.2328.726.914.811.512
1500
R 59396.887.9514.212.75.231.514
150
R 60406.431.7539.638.122.332.312
2500
R 61419.111.1317.5167.751.514
300 600
R 62419.115.8822.420.610.491.514
900
R 63419.125.433.331.817.32.314
1500
R 64454.037.9514.212.75.231.516
150
R 65469.911.1317.5167.751.516
300 600
R 66469.915.8822.420.610.491.516
900
R 67469.928.5836.635.119.812.316
1500
R 68517.537.9514.212.75.231.518
150
R 69533.411.1317.5167.751.518
300 600
R 70533.419.0525.423.912.321.518
900
R 71533.428.5836.635.119.812.318
1500
R 72558.87.9514.212.75.231.520
150
R 73584.212.719.117.58.661.520
300 600
R 74584.219.0525.423.912.321.520
900
R 75584.231.7539.638.122.332.320
1500
R 76673.17.9514.212.75.231.524
150
R 77692.1515.8822.420.610.491.524
300 600
R 78692.1525.433.331.817.32.324
900
R 79692.1534.9344.541.424.822.324
1500

Style R Ring Joint Gaskets Dimensions (for ASME B16.47 Series A flanges)

RTJ GASKET RING NUMBERDia
P
Width
A
HeightOct
C
Oct
R1
NPS
CLASS
Oval
B
Oct
H
R 93749.319.0523.912.321.526
300 600
R 94800.119.0523.912.321.528
300 600
R 95857.2519.0523.912.321.530
300 600
R 96914.422.2326.914.811.532
300 600
R 97965.222.2326.914.811.534
300 600
R 981022.3522.2326.914.811.536
300 600
R 100749.328.5835.119.812.326
900
R 101800.131.7538.122.332.328
900
R 102857.2531.7538.122.332.330
900
R 103914.431.7538.122.332.332
900
R 104965.234.9341.424.822.334
900
R 1051022.3534.9341.424.822.336
900

Style RX Ring Joint Gaskets Dimensions

RTJ GASKET RING NUMBER720-9602900#3000#5000#ODHEIGHTWIDTHGASKET Wt. ( kg )
RX201 ½–1 ½1 ½76.219.058.740.24
RX232, 2 1/16–93.2725.411.910.52
RX24––2, 2 1/162, 2 1/16105.9725.411.910.6
RX25–––3 1/8109.5519.058.740.5
RX262 ½ , 2 9/16–––111.9125.411.910.64
RX27––2 ½, 2 9/162 ½, 2 9/16118.2625.411.910.68
RX313 , 3 1/8–3, 3 1/8134.5425.411.910.78
RX35–––3, 3 1/8147.2425.411.910.86
RX374 , 4 1/16–4, 4 1/16–159.9425.411.910.95
RX39–––4, 4 1/16172.6425.411.911.03
RX415, 5 1/8–5, 5 1/8–191.6925.411.911.15
RX44–––5, 5 1/8204.3925.411.911.23
RX456, 7 1/16–6, 7 1/16–221.8425.411.911.34
RX46–––6, 7 1/16222.2528.5813.491.66
RX47–––8245.2641.2819.843.88
RX498, 9–8, 9280.5925.411.911.72
RX50–––8, 9283.3631.7516.662.43
RX5310, 11–10, 11334.5725.411.912.06
RX54–––10, 11337.3431.7516.662.92
RX5712, 13 5/8–12, 13 5/8391.7225.411.912.42
RX63––14441.7350.82711.96
RX6516, 16 3/4–––480.6225.411.913
RX66––16, 16 3/4–457.9931.7516.664.25
RX6918–544.1225.411.913.41
RX70––18–550.0641.2819.849.12
RX7320, 21 1/4–––596.1131.7513.495.27
RX74––20, 20 3/4–600.8641.2819.8410.01
RX82–1––67.8725.411.910.36
RX84–1 ½––74.2225.411.910.4
RX85–2––90.0925.413.490.4
RX86–2 ½––103.5828.5815.090.81
RX87–3––113.1128.5815.090.9
RX88–4––139.2931.7517.481.46
RX89–3 ½––129.7731.7518.263.09
RX90–5––174.6344.4519.847.75
RX91–10––286.9445.2430.181.5
RX998–8–245.6725.411.912.2
RX201–––1 3/851.4611.35.740.1
RX205–––1 13/1662.3111.15.560.13
RX210–––2 9/1697.6419.059.530.35
RX215–––4 1/16140.8925.411.910.8

Style BX Ring Joint Gaskets Dimensions

RTJ GASKET RING NUMBER2000#3000#5000#10000#15000#20000#OUTSIDE DIAHEIGHT 
OF THE RING
WIDTH 
OF THE RING
RTJ GASKET 
WEIGHT KG
BX 150–––1 11/161 11/16–72.199.39.30.13
BX 151–––1 13/161 13/161 13/1676.49.639.630.15
BX 152–––2 1/162 1/162 1/1684.6810.2410.240.19
BX 153–––2 9/162 9/162 9/16100.9411.3811.380.29
BX 154–––3 1/163 1/163 1/16116.8412.412.40.4
BX 155–––4 1/164 1/164 1/16147.9614.2214.220.55
BX 156–––7 1/167 1/167 1/16237.9218.6218.621.87
BX 157–––999294.4620.9820.982.97
BX 158–––111111352.0423.1423.144.35
BX 159–––13 5/8––426.7225.725.76.53
BX 160––13 5/8–––402.5923.8313.743.06
BX 161––16 ¾–––491.4128.0716.215.35
BX 162––16 3/416 3/416 3/4–475.4914.2214.221.94
BX 163––18 3/4–––556.1630.117.376.9
BX 164–––18 3/418 3/4–570.5630.124.595.86
BX 165––21 ¼–––624.7132.0318.498.76
BX 166–––21 ¼––640.0332.0326.1412.82
BX 16726 3/4–––––759.3635.8613.118.53
BX 168–26 3/4––––765.2535.8616.0510.54
BX 169–––5 1/8––173.5115.8512.930.73
BX 170–––6 5/86 5/8–218.0314.2214.221.03
BX 171–––8 9/168 9/16–267.4414.2214.221.24
BX 172–––11 5/3211 5/32–333.0714.2214.221.56
BX 3033030––––852.7537.9516.97

HOW TO ORDER RING JOINT GASKET

The following tables show how to select the correct ring joint gasket depending on the flange size (NPS), manufacturing norm (ASME or API), and flange rating:

Style R Ring Joint Gaskets

NOMINAL PIPE SIZEPRESSURE CLASSES
ASME B16.5API 6BASME B16.47 Series A
150#300# – 600#900#1500#2500#720# – 960# (1)2000#3000#5000#10000#150#300# – 600#900#
1/2”R-11R-12R-12R-13
3/4”R-13R-14R-14R-16
1”R-15R-16R-16R-16R-18R-16R-16R-16R-16R-82
1 1/4”R-17R-18R-18R-18R-21R-18R-18R-18R-18
1 1/2”R-19R-20R-20R-20R-23R-20R-20R-20R-20R-84
2”R-22R-23R-24R-24R-26R-23R-23R-23R-24R-85
2 1/2”R-25R-26R-27R-27R-28R-26R-26R-26R-27R-86
3”R-29R-31R-31R-35R-32R-31R-31R-31R-35R-87
3 1/2”R-33R-34R-37R-89
4”R-36R-37R-37R-39R-38R-37R-37R-37R-39R-88
5”R-40R-41R-41R-44R-42R-41R-41R-41R-44R-90
6”R-43R-45R-45R-46R-47R-45R-45R-45R-46
8”R-48R-49R-49R-50R-51R-49R-49R-49R-50
10”R-52R-53R-53R-54R-55R-53R-53R-53R-54R-91
12”R-56R-57R-57R-58R-60R-57R-57R-57R-57R-57
14”R-59R-61R-62R-63R-61R-61R-61R-61R-62
16”R-64R-65R-66R-67R-65R-65R-65R-65R-66
18”R-68R-69R-70R-71R-69R-69R-69R-69R-70
20”R-72R-73R-74R-75R-73R-73R-73R-73R-74
22”R-80R-81
24”R-76R-77R-78R-79R-77R-78
26”R-93R-100
28”R-94R-101
30”R-95R-102
32”R-96R-103
34”R-97R-104
36”R-98R-105

Style RX Ring Joint Gaskets

NPSPRESSURE RATING
API 6B
720#960#2000#2900#3000#5000#
1”RX-82
1 3/8”RX-201
1 1/2”RX-20RX-20RX-20RX-84RX-20RX-20
1 13/16″RX205
2”RX-23RX-23RX-23RX-85RX-24RX-24
2 1/2”RX-26RX-26RX-26RX-86RX-27RX-27
2 9/16”RX210
3”RX-31RX-31RX-31RX-87RX-31RX35
3 1/2”RX-89
4”RX-37RX-37RX-37RX-88RX-37RX-39
4 1/16″RX-215
5”RX-41RX-41RX-41RX-90RX-41RX-44
6”RX-45RX-45RX-45RX-45RX-46
8”RX-49
RX-99 (2)
RX-49RX-49RX-49
RX-99 (2)
RX-50
10”RX-53RX-53RX-53RX-91RX-53RX-54
12”RX-57RX-57RX-57RX-57
14”RX-63
16”RX-65RX-65RX-65RX-69
18”RX-69RX-69RX-69RX-73
20”RX-73RX-73RX-73RX82

Style BX Ring Joint Gaskets

NPSPRESSURE RATING
API 6BX
2000#3000#5000#10000#15000#20000#
1 11/16″BX-150BX-150
1 13/16″BX-151BX-151BX-151
2 1/16″BX-152BX-152BX-152
2 9/16″BX-153BX-153BX-153
3 1/16″BX-154BX-154BX-154
4 1/16″BX-155BX-155BX-155
5 1/8″BX-169
6 5/8″BX-170BX-170
7 1/16″BX-156BX-156BX-156
8 9/16″BX-171BX-171
9″BX-157BX-157BX-157
11″BX-158BX-158BX-158
11 5/32″BX-172BX-172
13 5/8″BX-160BX-159BX-159BX-159
16 3/4″BX-161  BX-162BX-162BX-162
18 3/4″BX-163BX-164BX-164
21 1/4″BX-165BX-166
26 3/4″BX-167BX-168
30″BX-303BX-303

KAMMPROFILE GASKET

WHAT ARE KAMMPROFILE GASKETS?

A Kammprofile gasket, also known as a serrated or grooved gasket, is a high-performance sealing solution designed for use in a wide range of industrial applications, particularly where tight sealing under varying pressures and temperatures is required. It combines the benefits of soft gasket materials with the strength of metal, offering a versatile and reliable sealing option for flanges and other joint types.

The core feature of a Kammprofile gasket is its metal core, which is typically made from stainless steel or other corrosion-resistant alloys. The core is mechanically processed to have a concentrically serrated profile on both sealing surfaces. These grooves enhance the sealing efficiency by concentrating the compressive forces applied upon them. The serrated metal core is covered on one or both sides with a layer of soft sealing material, such as flexible graphite, PTFE (polytetrafluoroethylene), or non-asbestos-compressed fiber. This soft layer helps to create an effective seal by conforming to the flange surfaces and filling any minor irregularities.

A Kammprofile gasket (or “Camprofile”) is manufactured by applying a sealing layer in non-metallic materials (such as graphite, PTFE-Teflon, ceramic fibers, non-asbestos, Mica, etc) or metallic materials (such as aluminum or silver) on both sides of a metal core featuring concentric grooves of 1 mm Cam-Pitch. This sealing product, called also a “grooved metal gasket” or “corrugated metal gasket”,  is used for high-pressure and temperature oil & gas applications.

kamprofile gasket

Kammprofile gaskets are used in many industrial, petrochemical, power generation, and nuclear installations (to seal flanges, heat exchangers, superheaters, and, other pressure equipment) and are preferred to Spiral Wound Gaskets for processes with constant high pressure/temperatures requiring strong bolt-loads and remarkable flanged joints’ resistance.

Kammprofile gaskets fit smooth and stock flange surface finish (3.2 to 6.3 μm Ra, i.e. 125-250 RMS).

The common thickness of a Kammprofile gasket is between 2 and 4 mm (3 mm is the most common specification in petrochemical applications).

A Kammprofile gasket offers several benefits, due to its wide sealing area and construction:

  • May resist temperatures up to approx. 1000°C (the Kammprofile temperature rating depends on the materials of the metal core and the sealing layer)
  • May rate up to 250 bars, which is a considerable pressure rating
  • The gasket does not damage the flange surface, due to the protection offered by the sealing layer
  • The gasket can absorb fluctuations in temperature and pressure
  • It is more tolerant than Spiral Wound Gaskets to improper bolting torques
  • Suits both light and heavyweight flanges, even of large sizes
  • After assembly, the thickness of the sealing material is extremely low (0.1 – 0.2 mm), thus reducing leaks and failure rates
  • The core of a Kammprofile gasket can be re-used after cleaning and fitting the gasket with new layering material. This is critical for expensive applications, such as heat exchanger gaskets that are made of exotic, expensive, materials (Inconel, Monel, Hastelloy, and Cupronickel).

Kamprofile gasket grooved

An outer metallic (integral or floating) ring may be added to the gasket, to facilitate the centering of the gasket during the installation on a flange. The sealing layers protect the flange surface and reinforce the seal.

KAMMPROFILE GASKET TYPES

Overall Design

Kammprofile gaskets, recognized for their high integrity sealing capability, adaptability, and resilience in challenging conditions, come in various types to suit different applications and flange configurations. These variations primarily concern the presence and type of guide rings and the choice of facing material. Here’s an overview of the primary types of Kammprofile gaskets:

1. Basic Kammprofile Gasket:

  • Description: This is the simplest form, consisting of a serrated metal core without any additional layers or coatings. The core’s grooves engage directly with the flange surfaces.
  • Applications: Suitable for applications where the flanges are smooth and clean, and where there’s no need for additional compression limiting or flange protection.

2. Kammprofile with Integral Outer Ring:

  • Description: This type includes an integral outer guide ring, typically made from the same material as the core. The outer ring centers the gasket on the flange and acts as a compression stop, preventing over-tightening.
  • Applications: Ideal for standard raised-face flanges, providing additional alignment and protection for the gasket and flange faces.

3. Kammprofile with Loose Outer Ring:

  • Description: Similar to the integral type but with a loose outer ring, allowing for easier alignment and installation. The loose ring can also serve as a compression stop.
  • Applications: Used with raised face and flat face flanges, especially where alignment under bolt tightening is a concern.

4. Kammprofile with Inner Ring:

  • Description: Features a serrated metal core covered with a soft sealing material and includes an inner ring that fits within the gasket’s serrations. The inner ring provides additional radial strength and helps prevent the inward buckling of the soft sealing layer.
  • Applications: Particularly useful for protecting the gasket against corrosive or erosive media, and in applications involving turbulent flow.

5. Kammprofile with Both Inner and Outer Rings:

  • Description: Combines the features of both inner and outer rings, offering the benefits of centering, protection from over-compression, and enhanced sealing performance against erosion and corrosion.
  • Applications: Suited for a wide range of applications, including raised face, flat face, and male-female flanges in more demanding operational conditions.

Parallel vs. Convex Core

Kammprofile gaskets, known for their versatility and sealing efficiency in various industrial applications, can be designed with different core profiles to enhance their sealing capabilities under specific conditions. Two notable variations in the design of the metal core are parallel root cores and convex root cores. Each design influences the gasket’s compressibility, recovery, and overall sealing performance.

Kammprofile with Parallel Root Core:

  • Description: In this design, the serrations or grooves on the metal core are straight and parallel to each other, creating a uniform profile across the gasket’s surface. The uniform depth and width of the grooves ensure consistent compression and sealing along the entire gasket.
  • Advantages: The parallel root core provides a reliable seal by evenly distributing the compressive force across the gasket’s surface. It is suitable for a wide range of applications, offering good recovery and resilience under fluctuating loads and temperatures.
  • Applications: Commonly used in standard flange connections where the gasket faces relatively consistent pressures and temperatures. It’s effective in sealing both liquids and gases in various industrial processes.

Kammprofile with Convex Root Core:

  • Description: This design features serrations with a convex curve at the root of each groove, rather than straight parallel lines. The convex shape increases the contact pressure at the peaks of the serrations, enhancing the gasket’s ability to seal under lower bolt loads.
  • Advantages: The convex root core design provides higher sealing efficiency, especially in applications where bolt load is limited or where flange surfaces may not be perfectly aligned. It can also offer improved resilience and better stress distribution, reducing the risk of leakage.
  • Applications: Particularly useful in applications where bolt loading is restricted, in lightweight flanges, or in scenarios where the gasket must seal effectively under lower compressive forces. It’s also suitable for sealing irregular or damaged flange surfaces.

Kammprofile Gasket Designs

 

KAMMPROFILE GASKET MATERIALS

Metal Core Materials

The core material of a Kammprofile gasket shall match the material of the piping system

Kammprofile Core MaterialsDIN
Designation
DIN Material NumberAISI ASTM UNS
Designation
British Standard
Designation
Hardness
HB/HV
Temperature in C°
Min.           Max.
Density in gr/cm3
Soft Iron90  –  100–  605007.85
Steel (LCS)RSt. 37.21.0038100  –  130–  405007.85
Stainless Steel 304X5 CrNi 18101.4301304304S15/16/31130  –  180-2505507.9
Stainless Steel 304 LX2CrNi 19111.4306304L304S11130  –  190-2505507.9
Stainless Steel 309X15CrNiSi 20121.4828309309S24130  –  190-10010007.9
Stainless Steel 316 L(1)X2CrNiMo 17131.4404316L316S11/13130  –  190-1005507.9
Stainless Steel 316 TiX6CrNiMoTi 17121.4571316Ti320S31130  –  190-1005507.8
Stainless Steel 321X6CrNiTi 18101.4541321321S12/49/87130  –  190-2505507.9
Stainless Steel 347X6CrNiNb 18101.4550347347S31130  –  190-2505507.9
AluminiumAl 99,53.025520  –    23-2503002.73
Silver28*-25075010.5
Copper2.009050  –    80-2504008.9
Nickel 200Ni 99,22.4066N022003072-76 NA1190  –  120-2506008.9
Monel 400 ®NiCu 30 Fe2.4360N044003072-76 NA13110  –  150-1256008.8
Inconel 600 ®NiCr 15 Fe2.4816N066003072-76 NA14120  –  180-1009508.4
Incoloy 800 ®X10NiCrAITi 32201.4876N088003072-76 NA15140  –  220-1008508.0
Incoloy 825 ®NiCr 21 Mo2.4858N088253072-76 NA16120  –  180-1004508.14
Hastelloy B2 ®NiMo 282.4617N10665170  –  230-2004509.2
Hastelloy C276 ®NiMo16Cr15W2.4819N10276170  –  230-2004508.9
TitaniumTi 99,83.7025110  –  140-2503504.5

Sealing Layer

The most common layer materials for Kammprofile gaskets are graphite and PTFE (Teflon).
The advantages of a graphite layering material are:

  • Excellent gas tightness qualities
  • Non-aging properties
  • Very good chemical resistance
  • Resistance to high (fluctuating) temperatures and pressures

PTFE is also used due to its excellent chemical resistance, resistance to temperatures up to 250°C, and excellent sealing properties for gas applications.

Sealing Layer Material for KammprofileTemperature in C°
Min.     Max.
Max. operating pressure in BarsGas tightnessRecommended Application
Graphite-200550250GoodAggressive media
PTFE (Teflon ® )-200250100GoodAggressive media
Non-asbestos-100250100GoodGas and liquids
Silver-200750250GoodAggressive media
 

KAMMPROFILE GASKET DIMENSIONS

KAMMPROFILE GASKET Class 150-400

Kammprofile gasket dimensions for AMSE B16.5 flanges

Kammprofile gasket size

NPSd1d2d3
150300400
1/22333.344.450.850.8
3/428.639.753.963.563.5
136.547.663.569.869.8
1¼44.460.37379.479.4
1½52.469.882.592.192.1
269.888.9101.6108108
2½82.5101.6120.6127127
398.4123.8133.4146.1146.1
3½111.1136.5158.8161.9158.7
4123.8154171.5177.8174.6
5150.8182.6193.7212.7209.5
6177.8212.7219.1247.7244.5
8228.6266.7276.2304.8301.6
10282.6320.7336.5358.8355.6
12339.7377.8406.4419.1415.9
14371.5409.6447.7482.6479.4
16422.3466.7511.2536.6533.4
18479.4530.2546.1593.7590.5
20530.2581603.2650.9644.5
24631.8682.6714.4771.5765.2

All values in millimeters

KAMMPROFILE GASKET Class 600-2500

Kammprofile gasket dimensions for AMSE B16.5 flanges

Kammprofile gasket size

NPSd1d2d3
60090015002500
1/22333.350.860.360.366.7
3/428.639.763.566.766.773
136.547.669.876.276.282.5
1¼44.460.379.485.785.7101.6
1½52.469.892.195.295.2114.3
269.888.9108139.7139.7142.8
2½82.5101.6127161.9161.9165.1
398.4123.8146.1165.1171.5193.7
3½111.1136.5158.7
4123.8154190.5203.2206.4231.7
5150.8182.6238.1244.5250.8276.2
6177.8212.7263.5285.8279.4314.3
8228.6266.7317.5355.6349.3384.1
10282.6320.7369.9431.8431.8473
12339.7377.8454495.3517.5546.1
14371.5409.6488.9517.5574.7
16422.3466.7561.9571.5638.1
18479.4530.2609.6635701.7
20530.2581679.5695.3752.4
24631.8682.6787.4835898.5

All values in millimeters

JACKETED GASKET

WHAT IS A JACKETED GASKET?

A jacketed gasket is a type of composite gasket used in industrial piping, vessels, and heat exchangers, designed to handle a wide range of temperatures, pressures, and chemical conditions. It consists of a soft, compressible filler material that is enclosed in a metal jacket. The metal jacket provides mechanical strength, chemical resistance, and thermal stability, while the filler material ensures the gasket conforms well to the flange surfaces, offering an effective seal.

Jacketed gaskets can be fully jacketed, partially jacketed, or single-jacketed, depending on the application requirements:

  • Fully Jacketed Gaskets: The filler material is completely enclosed in the metal jacket, offering maximum protection and strength. This type is typically used in applications involving high pressures and temperatures.
  • Partially Jacketed Gaskets: Only certain sections of the filler material are covered by the metal jacket. This design is chosen based on specific sealing and operational needs, providing a balance between the compressibility of the filler and the strength of the metal jacket.
  • Single-Jacketed Gaskets: The metal jacket covers only one face and the inside edge of the gasket. This type is suitable for applications where the gasket needs extra strength on one side, such as in narrow flanges.
A metal jacket gasket requires flat face flanges with a smooth face finish to seal effectively.

The size range and thickness tolerances for this type of gasket are covered by ASME B16.21 specification:

  • OD: Less than 5,000mm
  • Thickness: 2~8mm with tolerance +0.03 inch. to -0.000 inch (+0.8mm, -0.0mm)

Metal jacket gaskets

JACKETED GASKET MATERIALS

Jacketed gaskets are built using the following materials:

  • Metal Jacket: Common materials for the jacket include stainless steel, aluminum, copper, Monel, and Inconel. The choice of metal is based on the required thermal, chemical, and mechanical properties.
  • Filler Material: Typical fillers include flexible graphite, PTFE (Polytetrafluoroethylene), non-asbestos compressed fiber, and ceramic. The filler selection depends on the sealing requirements, including chemical compatibility and temperature resilience.

The table shows the recommended temperature range for common metal jacket materials:

Jacket MaterialsHardness HBTemp.℃
Carbon Steel90-60~+450
304 (L)130-270~+550
316 (L)130-270~+550
321130-270~+550
Monel110-60~+500
Inconel90-60~+600
AL30-250~+300
CU80-250~+400

JACKETED GASKET TYPES

The two main types of metal jacketed gaskets are the single and the double jacket designs. Besides these two basic types, other designs are available on the market as illustrated below:

Double Jacketed CorrugatedDouble Jacketed Corrugated
— soft filler

Reduced contact area, enhances compression characteristics, suitable for uneven flanges.
Double Jacketed Corrugated — metal fillerDouble Jacketed Corrugated
— metal filler

Usually stainless outer casing with soft iron filler ring.
Core material available St. St. -304.316L.321
Soft iron, Monel, Inconel
Single Corrugated — asbestos rope fillerSingle Corrugated
— asbestos rope filler

Typically used on very poor or pitted flanges, low bolt loading requirement.
Metal Jacket Laminates — soft fillerMetal Jacket Laminates
— soft filler

Combines flexible graphite with stainless steel core material
Solid metal ring machinedSolid metal ring machined on each contact face to provide a serrated surface finish covered with Graphite.
PTFE Nonas or Asbestos.
Double Jacketed – soft fillerDouble Jacketed – soft filler
Used on high-temperature pressure applications or where corrosion problems may exist
Single Jacketed – metal filler – partly enclosedSingle Jacketed – metal filler
– partly enclosed

Very seldom used, old design. Used in applications where poor or pitted flanges exist on one face.
Single Jacketed – Soft filler – partly enclosedSingle Jacketed – Soft filler
– partly enclosed

Used on narrow flanges
Single Jacketed – Soft filler – open outside edgeSingle Jacketed – Soft filler
– open outside edge

Used in narrow flanges, protection of filler cleared for by casing
Single Corrugated – no fillerSingle Corrugated – no filler
Used mainly in valve applications, small recess gap. Sometimes referred to as the Taylor ring.

JACKETED GASKET DIMENSIONS

JACKET GASKET Class 150-400

Jacketed gasket dimension
Jacketed gasket dimension
NPSd1d2
150300400
1/223.844.550.850.8
3/431.85463.563.5
136.563.569.969.9
1¼467379.479.4
1½52.482.692.192.1
273.2101.6108108
2½85.9120.6127127
3107.8133.4146.1146.1
4131.8171.5177.8174.7
5152.4193.8212.8209.5
6190.5219.1247.7244.5
8238.3276.3304.8301.7
10285.8336.6358.8355.6
12342.9406.4419.1415.9
14374.7447.7482.6479.5
16425.5511.2536.6533.4
18489546.1593.7590.6
20533.4603.3650.9644.5
24641.4714.4771.6765.3
NPSd1150300400

 

JACKET GASKET Class 600-2500

Jacketed gasket dimensions for AMSE B16.5 flanges

Jacketed gasket dimension

NPSd1d2
60090015002500
1/223.850.860.460.466.8
3/431.863.566.766.773.1
136.569.976.276.282.5
1¼4679.485.885.8101.6
1½52.492.195.395.3114.3
273.2108139.7139.7143
2½85.9127161.9161.9165.1
3107.8146.1165.1171.5193.8
4131.8190.5203.2206.5231.9
5152.4238.2244.6250.9276.3
6190.5263.6285.8279.4314.5
8238.3317.5355.6349.3384.3
10285.8396.9431.8431.8473.2
12342.9454.1495.3517.6546.1
14374.7489517.6574.7
16425.5562571.5638.2
18489609.6635701.8
20533.4679.5695.5752.5
24641.4787.4835.1898.6

HOW TO ORDER A METAL JACKETED GASKET

The following information should be provided to the gasket supplier to order a jacket gasket properly:

  • Outside diameter
  • Inside diameter (NPS)
  • Shape per standard index
  • Type Number
  • Thickness
  • Materials (metal or metal filler)
  • Bar size
  • Radii
  • Distance from the centerline of the gasket to the centerline of the bars

VIDEO: TYPES OF GASKETS FOR FLANGES

The video below shows the main features of the above types of gaskets for flanges. We have several other educational videos about key piping, that describe products in a simple and basic way. Take a look!

**DISCLAIMER: Accuracy and Reliability of Content**

The information provided in this blog post is intended for general informational purposes only and should not be construed as professional advice. While we strive to provide accurate and up-to-date information, we make no representations or warranties of any kind, express or implied, about the completeness, accuracy, reliability, suitability, or availability of the content contained herein. Any reliance you place on the information presented in this blog post is strictly at your own risk. We disclaim any liability for any loss or damage, including without limitation, indirect or consequential loss or damage, or any loss or damage whatsoever arising from reliance on information contained in this blog post. We encourage readers to verify the accuracy and relevance of any information presented here with other sources and seek professional advice or guidance where appropriate. Links to third-party websites or resources provided in this blog post are for convenience only and do not imply endorsement or approval of the content, products, services, or opinions expressed on those websites. We have no control over the nature, content, and availability of those sites and assume no responsibility for their accuracy, legality, or decency. We reserve the right to modify, update, or remove any content in this blog post at any time without prior notice. By accessing and using this blog post, you acknowledge and agree to these terms and conditions. If you do not agree with these terms, please refrain from accessing or using the information provided herein.

About the Author

Picture of Projectmaterials Team

Projectmaterials Team

Blog.projectmaterials.com is an online resource dedicated to providing in-depth information, analysis, and educational content related to the fields of project materials management, engineering, and procurement, particularly within the oil & gas, construction, shipbuilding, energy, and renewable energy sectors. It aims to serve professionals and enthusiasts in these industries by offering valuable insights into materials, equipment, and techniques used in various projects, focusing on the selection, application, and maintenance of these resources. Key features of the blog include: * Educational Articles: Comprehensive posts that cover topics ranging from the technical aspects of piping products (pipes, valves, fittings, flanges, gaskets, bolts, instrumentation) to structural steel and process equipment (including oil extraction systems, drilling rigs, wellheads, pumps, compressors, and separation systems). * Industry Insights: Updates on the latest trends, technologies, and regulatory changes affecting the industries covered. * Guides and How-Tos: Practical advice on selecting the right materials and equipment for specific applications, as well as tips on installation, maintenance, and troubleshooting. * Safety and Standards: Information on safety equipment for production sites, risk mitigation procedures, and an overview of relevant industry standards and regulatory frameworks. The website is designed to support the professional development of engineers, procurement specialists, project managers, and other stakeholders involved in project plant businesses, by disseminating critical know-how and best practices. Whether readers are new to the field or seasoned professionals, blog.projectmaterials.com offers resources to enhance their understanding and performance in managing project materials effectively.

Should you wish to reach out to the author of this article, we invite you to contact us via email

41 Responses

  1. Hello

    Please kindly provide
    • QUOTE & ESTIMATED WEIGHT for the items below:

    SEAL:OIL TYPE:SEAL OIL STUB SH
    Qty: 3

    SEAL:RING TYPE:FLAT SEAL ID:ST
    Qty: 1

    SEAL:RING TYPE:FLAT SEAL ID:ST
    Qty: 1

    Kelly L.
    Procurement Coordinator
    BLN Corporate Int’l Ltd

    1. Dear Kelly L.,

      Thank you for reaching out to us with your request for a quote and estimated weight for the items you mentioned. We appreciate your interest in our products.

      To provide you with an accurate quote and estimated weight, we kindly request some additional information. Could you please provide us with the specific dimensions or specifications for the “SEAL: OIL TYPE: SEAL OIL STUB SH” and “SEAL: RING TYPE: FLAT SEAL ID: ST”? This will help us determine the most suitable gaskets for your requirements.

      Once we receive the necessary details, our team will promptly prepare a quote and estimated weight for the requested items. We strive to offer competitive prices and high-quality products, ensuring your satisfaction with our services.

      Thank you for considering our company, and we look forward to assisting you further with your procurement needs.

      Best regards,

      [Your Name]
      [Your Company Name]

  2. I’d like to know if we CANNOT avoid matting rtj flg. Ss to cs. What is the best rtj gasket material to use? Is it either soft iron or 316?
    I noted that we should use softer materials, specifically soft iron. But how about galvanic reactions?

    1. In response to your question, the best gasket material for mating a stainless steel (SS) flange with a carbon steel (CS) flange would depend on several factors. Soft iron and 316 stainless steel are both commonly used gasket materials for this application.

      Soft iron gaskets are often preferred in applications where there is a significant difference in hardness between the two flange materials. Soft iron is a malleable material that can conform to the irregularities in the flange surfaces, providing a reliable seal. However, it is important to consider the potential for galvanic reactions when using soft iron with stainless steel.

      Galvanic reactions can occur when two dissimilar metals are in contact, especially in the presence of an electrolyte such as moisture or corrosive fluids. In this case, the stainless steel flange and the soft iron gasket could form a galvanic couple, potentially leading to accelerated corrosion. To mitigate this risk, it is recommended to apply an insulating coating or gasket coating to the soft iron gasket to prevent direct contact with the stainless steel flange.

      On the other hand, 316 stainless steel gaskets are inherently more resistant to galvanic corrosion when mated with stainless steel flanges. 316 stainless steel is an alloy that contains molybdenum, which enhances its corrosion resistance. Therefore, using a 316 stainless steel gasket can help minimize the risk of galvanic reactions and potential corrosion.

      Ultimately, the choice between soft iron and 316 stainless steel gaskets for mating SS and CS flanges should consider the specific operating conditions, the potential for galvanic reactions, and the need for corrosion resistance. It is recommended to consult with a knowledgeable engineer or a gasket manufacturer to determine the most suitable gasket material for your specific application.

  3. I’d like to know if we can avoid matting rtj flg. Ss to cs. What is the best rtj gasket material to use? Is it either soft iron or 316?
    I noted that we should use softer materials, for my case i will choose soft iron. But how about galvanic reactions?
    Please advise

    1. In response to Hanis’ question about avoiding matting RTJ flanges from stainless steel (SS) to carbon steel (CS) and the best material for an RTJ gasket, the choice between soft iron or 316, it is important to consider galvanic reactions.

      When it comes to avoiding matting RTJ flanges between SS and CS, it is generally recommended to use an insulating material between the two metals. This can help prevent galvanic corrosion caused by the contact between dissimilar metals. Using a gasket made of a softer material, like soft iron, can be a suitable choice in this scenario.

      However, it is crucial to assess the specific conditions and requirements of your application. Galvanic reactions can still occur if the gasket material is not carefully selected. Soft iron is often preferred due to its ability to conform to irregularities on the flange surface, ensuring a better seal. Nevertheless, it is essential to consult with an expert or refer to industry guidelines to determine the most appropriate gasket material for your specific SS to CS application.

      Considering your concern about galvanic reactions, it is worth noting that using a gasket made of soft iron should help mitigate this issue to a considerable extent. Soft iron is less likely to cause galvanic corrosion when in contact with SS or CS compared to other materials. However, it is always recommended to analyze the overall system and consult with professionals to fully address any potential galvanic reaction concerns.

      In summary, while using a softer gasket material like soft iron is generally a good choice for RTJ flanges between SS and CS, it is crucial to consider the specific requirements of your application and potential galvanic reactions. Seeking guidance from industry experts or referring to relevant standards and guidelines will help ensure the best choice for your specific situation.

    1. Thank you for your appreciation! We’re glad that you found the information on types of gaskets for flanges useful. If you have any specific questions or need further assistance regarding gaskets or any other related topic, please feel free to ask. We are here to help!

  4. We thoroughly enjoyed reading this informative article on gaskets. As a leading provider of sealing solutions, Asian Sealing takes pride in manufacturing high-quality gaskets that meet the diverse needs of industries worldwide. Our commitment to excellence, precision engineering, and durable materials ensures that our gaskets deliver optimal performance and reliability.

    For those seeking top-notch gasket solutions, we invite you to explore our website at http://www.asiansealing.in to discover our extensive range of products and learn more about how we cater to various industries.

    https://asiansealing.in/ring-gasket/

  5. Dear Sir
    I Need a supplier or Individuals who can Participate to ongoing contract to supply any of this items :

    1.T-shirt
    2.Towels,
    3.Hat caps
    4.Medical Glove
    5.Disposable Isolation Gowns
    6.Medical Face Masks
    7.Medical Infrared Thermometer
    8.ppe
    9.Medical Product
    10.Drilling Pipes
    11.Hospital equipment
    12.industrial machine
    13 COTTON YARN
    To my Organization for Bidding Project.

    Thanks
    mr muhammad

  6. DEAR SIR/MODOM
    OUR COMPANY NEED FLANGE RING JOINT OF BODY
    46315916207
    6606/ SP
    MAKER :JUCKER
    IF YOUR COMPANY HAVE THIS PLEASE SEND ME EMAIL .

  7. Thanks for sharing Gasket’s blog information. You can buy Ring Joint Gasket Ring type joint gasket (RTJ Gasket) is high integrity sealing gasket, high temperature and high-pressure gasket for applications in the petroleum industry, oilfield drilling, pressure vessels joints, pipes, and valves, etc from Goodrich Gasket Pvt. Ltd.

    1. I’d like to know if we CANNOT avoid matting rtj flg. Ss to cs. What is the best rtj gasket material to use? Is it either soft iron or 316? I noted that we should use softer materials, specifically soft iron. But how about galvanic reactions?

      1. Hanis, when it comes to matting RTJ flanges from stainless steel (SS) to carbon steel (CS), it is generally recommended to use a softer material for the RTJ gasket. Soft iron is often considered the best choice for this application due to its excellent compressibility and ability to conform to irregularities on the flange surfaces.

        Regarding your concern about galvanic reactions, it is essential to consider the potential for corrosion when different metals come into contact with each other. In the case of SS and CS, galvanic reactions can indeed occur. However, by using a soft iron RTJ gasket, you can minimize the risk of galvanic corrosion. Soft iron is more cathodic compared to SS and CS, meaning it will sacrifice itself to protect the other metals from corrosion.

        It is worth mentioning that in some specific cases, 316 stainless steel can also be used as an RTJ gasket material for SS to CS matting. However, soft iron is generally preferred due to its better sealing capabilities and lower cost.

        In summary, if you cannot avoid matting RTJ flanges from SS to CS, it is recommended to use a soft iron RTJ gasket. This choice minimizes the risk of galvanic corrosion and ensures effective sealing in high-pressure and high-temperature applications.

  8. Dear sir
    I am Ronak Gothi from Ahmedabad city and Mechanical Engineer. is Required marketing job in company product.
    please call me.

    1. Thanks for sharing your valuable information on Types of Gaskets Flanges (Soft, Spiral, Ring Joint). I prefer using Horiaki India Rubber Metal Gaskets, they also deal in O-Rings seals, Perfluoroelastomer Ffkm O-Rings, and more.Perfluoroelastomer Ffkm O-Rings, and more.

  9. Smooth finish is used with a metallic gasket whereas a serrated finish is used with a non-metallic gasket.  The soft material of gaskets is set in this serration and prevents liquid or gas from passing from the flange joint.

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.