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Types of Gaskets for Flanges (Soft, Spiral, Ring Joint)

Learn about the 5 key flange gaskets types (used in the oil and gas industry): non-asbestos gaskets full and raised face (used for low-pressure, low-temperature and non-critical applications), spiral wound gaskets (for higher temperature and pressure oil and gas applications), Ring joint gaskets style R, RX, BX (for RTJ flange faces), Kammprofile and Jacketed gaskets. The article describes the scope of each type of gasket, the dimensions to ASME B16.20 and ASME B16.21, the materials and give some indications to select the right gasket for piping applications.

Table of Content

NON-ASBESTOS GASKET

Non-asbestos gaskets are the simplest type of gasket for flanges and are produced by cutting graphite, organic or inorganic non asbestos sheets into shape (generally, with water jet cutting machines). This type of gaskets for flanges suits low pressure, low temperature, and non-critical piping and plumbing applications.

The two main types of non-asbestos gaskets are the “full face” (FF) for FF flanges and the “flat ring” type for raised face flanges (RF).

 

Non asbestos gasket for flange

 

Non-asbestos gaskets have fully replaced asbestos gaskets for decades as studies demonstrated the risks (for human health) associated with the production, use, and disposal of asbestos materials. The ASME B16.21 specification covers non-asbestos sheet gaskets (types, sheet materials, dimensions, dimensional tolerances, and marking requirements).

 

Full face and ring gasket
The terms, “flat-cut gaskets”, “die-cut gaskets”, “compressed sheet gaskets” and “asbestos-free gaskets” are synonyms to define this low-end family of flange gaskets.
To select the right material for non-asbestos gaskets, multiple factors shall be considered: fluid, temperature, pressure, fugitive emissions laws, and mechanical issues.

NON-ASBESTOS GASKET MATERIALS

 

Materials for soft gaskets

 

The most common materials used to manufacture compressed fiber gaskets are aramid fibers (Kevlar), glass fibers, elastomers, Teflon (PTFE), graphite, neoprene mixed with various 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

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.

NON-ASBESTOS GASKET DIMENSIONS

Soft Gaskets for ASME B16.5 Flanges

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

soft gaskets sizes

 

NPSd1
(ID)
d2 (GASKET OUTSIDE DIAMETER)
Class 150Class 300Class 400Class 600Class 900
1/2214854545464
3/4275767676770
1336773737379
427683838389
488695959598
260105111111111143
73124130130130.2165
389137149149149168
102162165162162
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

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

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 sold type.

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.

Indeed, a spiral wound gasket is designed to withstand, better than other types of flange gaskets, the mechanical stress generated by high temperature and pressure applications. Spiral wound gasket application range, therefore, from oil and gas to power generation.

Spiral wound gasket

The diameter of a spiral wound gasket may range between a few mm up to 5.000 mm, and the spiral wound gasket thicknesses range 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.

SPIRAL WOUND GASKET TYPES

A few different types of spiral wound gaskets exist, depending on:

  • the number of rings (outer and inner)
  • the materials of the inner and the outer ring of the gasket

spiral wound gaskets types

  • 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.

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

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

types of SW gaskets

SPIRAL WOUND GASKET 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 strip combined with a filler material. The formed metal strip in 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 the 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 the outer rings of a spiral wound gasket may be the same material of 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

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)1.100390 – 100-605007.85
Steel (LCS)RSt.37.21.0038100 – 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 282.4617N10665170 – 230-2004509,2
Hastelloy C276‘NiMo 16Cr15W2.4819N10276170 – 230-2004508.9
TitaniumTi 99,83.7025110 – 140-2505004,5

SPIRAL WOUND GASKET COLORS

Spiral wound gaskets made with different windings and filler materials are easy to spot, as each combination is designated by the application of color codes (the main color designates the winding materials, the stripes indicate the type of filler):

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 a number of 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

 

SPIRAL WOUND GASKET MARKING

The illustration shows the typical marking of spiral wound gaskets:

 

Spiral wound gasket marking

 

SPIRAL WOUND GASKETS DIMENSIONS

Class 150

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

 

Spiral wound gaskets dimensions
Spiral wound gaskets 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
38.147.860.576.2
44.554.169.985.9
255.669.985.9104.9
66.582.698.6124
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 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. 

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
38.147.860.582.6
44.554.169.995.3
255.669.985.9111.3
66.582.698.6130.3
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 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. 

Class 400

Dimensions of class 400 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
38.147.860.582.6
44.554.169.995.3
255.669.985.9111.3
66.582.698.6130.3
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 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. 

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
38.147.860.582.6
44.554.169.995.3
255.669.985.9111.3
66.582.698.6130.3
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 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. 

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
33.339.660.588.9
41.447.869.998.6
252.358.785.9143
63.569.998.6165.1
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 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. 

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
33.339.660.588.9
41.447.869.998.6
252.358.785.9143
63.569.998.6165.1
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 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. 

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
33.339.660.5104.9
41.447.869.9117.6
252.358.785.9146
63.569.998.6168.4
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 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 R, RX, BX

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).

RTJ 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-section 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 valves 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 flanges material but must have a lower hardness: this to ensure that the gasket, and not the flange, get 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 IronD1.1003 / 1.0335Aramco / StW24
LCSS1.1003 / 1.0335Aramco / StW24
CS360 LTCS360LTA516 Gr70
41404140UNS G4140042CrMo41.72254140
F5F5UNS K4254412CrMo1951.73625Cr 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 800HINC800HN088101.4958
Incoloy 825INC825N08825NiCr21Mo2.4858
904L904LN08904X1NiCrMoCu25-20-51.4539
F51F51S31803X2CrNiMoN22-5-31.44622205 /Duplex
F53F53S32750X2CrNiMoN25-7-41.441
F55F55S32760X2CrNiMoCuWN 25 7 41.4501Zeron 100
F60F60S32205Duplex
TitaniumTiR 504003.7035
17-4PH17-4PHS174001.4542630
S254S254S31254X1CrNiMoCuN20-18-71.4547F44 / 6Mo
C276C276N10276NiMo16Cr15W2.4819Hastelloy
Alloy 28Alloy28N08028X1 NiCrMoCuN 31 27 41.4563SANICRO 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 1757.157.9514.212.75.231.5
150
R 1860.337.9514.212.75.231.5
300 / 1500
1
2500
R 1965.17.9514.212.75.231.5
150
R 2068.287.9514.212.75.231.5
300 / 1500
R 2172.2411.1317.5167.751.5
2500
R 2282.557.9514.212.75.231.52
150
R 2382.5511.1317.5167.751.52
300 600

2500
R 2495.2511.1317.5167.751.52
900 / 1500
R 25101.67.9514.212.75.231.5
150
R 26101.611.1317.5167.751.5
300/ 600
2
2500
R 27107.9511.1317.5167.751.5
900 / 1500
R 28111.1312.719.117.58.661.5
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 33131.787.9514.212.75.231.5
150
R 34131.7811.1317.5167.751.5
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 ½1 ½1 ½76.219.058.740.24
RX232, 2 1/1693.2725.411.910.52
RX242, 2 1/162, 2 1/16105.9725.411.910.6
RX253 1/8109.5519.058.740.5
RX262 ½ , 2 9/16111.9125.411.910.64
RX272 ½, 2 9/162 ½, 2 9/16118.2625.411.910.68
RX313 , 3 1/83, 3 1/8134.5425.411.910.78
RX353, 3 1/8147.2425.411.910.86
RX374 , 4 1/164, 4 1/16159.9425.411.910.95
RX394, 4 1/16172.6425.411.911.03
RX415, 5 1/85, 5 1/8191.6925.411.911.15
RX445, 5 1/8204.3925.411.911.23
RX456, 7 1/166, 7 1/16221.8425.411.911.34
RX466, 7 1/16222.2528.5813.491.66
RX478245.2641.2819.843.88
RX498, 98, 9280.5925.411.911.72
RX508, 9283.3631.7516.662.43
RX5310, 1110, 11334.5725.411.912.06
RX5410, 11337.3431.7516.662.92
RX5712, 13 5/812, 13 5/8391.7225.411.912.42
RX6314441.7350.82711.96
RX6516, 16 3/4480.6225.411.913
RX6616, 16 3/4457.9931.7516.664.25
RX6918544.1225.411.913.41
RX7018550.0641.2819.849.12
RX7320, 21 1/4596.1131.7513.495.27
RX7420, 20 3/4600.8641.2819.8410.01
RX82167.8725.411.910.36
RX841 ½74.2225.411.910.4
RX85290.0925.413.490.4
RX862 ½103.5828.5815.090.81
RX873113.1128.5815.090.9
RX884139.2931.7517.481.46
RX893 ½129.7731.7518.263.09
RX905174.6344.4519.847.75
RX9110286.9445.2430.181.5
RX9988245.6725.411.912.2
RX2011 3/851.4611.35.740.1
RX2051 13/1662.3111.15.560.13
RX2102 9/1697.6419.059.530.35
RX2154 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 1501 11/161 11/1672.199.39.30.13
BX 1511 13/161 13/161 13/1676.49.639.630.15
BX 1522 1/162 1/162 1/1684.6810.2410.240.19
BX 1532 9/162 9/162 9/16100.9411.3811.380.29
BX 1543 1/163 1/163 1/16116.8412.412.40.4
BX 1554 1/164 1/164 1/16147.9614.2214.220.55
BX 1567 1/167 1/167 1/16237.9218.6218.621.87
BX 157999294.4620.9820.982.97
BX 158111111352.0423.1423.144.35
BX 15913 5/8426.7225.725.76.53
BX 16013 5/8402.5923.8313.743.06
BX 16116 ¾491.4128.0716.215.35
BX 16216 3/416 3/416 3/4475.4914.2214.221.94
BX 16318 3/4556.1630.117.376.9
BX 16418 3/418 3/4570.5630.124.595.86
BX 16521 ¼624.7132.0318.498.76
BX 16621 ¼640.0332.0326.1412.82
BX 16726 3/4759.3635.8613.118.53
BX 16826 3/4765.2535.8616.0510.54
BX 1695 1/8173.5115.8512.930.73
BX 1706 5/86 5/8218.0314.2214.221.03
BX 1718 9/168 9/16267.4414.2214.221.24
BX 17211 5/3211 5/32333.0714.2214.221.56
BX 3033030852.7537.9516.97

HOW TO ORDER RING JOINT GASKET

The following tables shows 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

KAMMPROFILE GASKET DEFINITION

A Kammprofile gasket 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 (as aluminum or silver) on both sides of a metal core featuring concentric grooves of 1 mm Cam-Pitch. This sealing product, called also “grooved metal gasket” or “corrugated metal gasket”,  is used for high-pressure and temperature oil & gas applications.

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.

 

 

kamprofile gasket

 

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 a 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

Kammprofile gaskets are available in two main configurations, parallel root cores/convex root cores, and two designs (with/without loose outer centering ring), as shown in the image below:

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

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
44.460.37379.479.4
52.469.882.592.192.1
269.888.9101.6108108
82.5101.6120.6127127
398.4123.8133.4146.1146.1
111.1136.5158.8161.9158.7
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

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
44.460.379.485.785.7101.6
52.469.892.195.295.2114.3
269.888.9108139.7139.7142.8
82.5101.6127161.9161.9165.1
398.4123.8146.1165.1171.5193.7
111.1136.5158.7
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

A Jacketed gasket features an inner soft material core and an outer metallic shell. The inner filler material provides resilience to the gasket, whereas the metal jacket protects the inner core of the gasket and withstands the pressure, the temperature, and the corrosion of the process.

Metal jacket gaskets are available with a single or double jacket and are widely used for pumps, valves, pressure vessels, and other mechanical equipment.
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 gaskets 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

Metal Jacket Materials

The table shows the most common metals used for jacketed gaskets and the recommended temperature range:

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

Inner Core Materials

Metal jacket gaskets have a soft inner core, which may be manufactured in materials as:

  • Non-Asbestos millboard and other non-asbestos materials (aramid, glass fiber, inorganic fibers, etc)
  • CAF
  • Rubber
  • PTFE
  • Graphite

JACKETED GASKET TYPES

The two main types of metal jacketed gasket 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 facing.
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 Taylor ring.

JACKETED GASKET DIMENSIONS

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
467379.479.4
52.482.692.192.1
273.2101.6108108
85.9120.6127127
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

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
4679.485.885.8101.6
52.492.195.395.3114.3
273.2108139.7139.7143
85.9127161.9161.9165.1
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 bars

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