fbpx

©

2009-2020 projectmaterialblog.com

Alloy Steel Pipe A335 Gr. P5, P9, P11, P22, P91

Learn about the alloy steel pipes specification ASTM A335 that covers “chrome-moly” seamless pipes with remarkable resistance to corrosion and good tensile strength at high-temperature service. Generally, ASTM A335 P11, P22, and P91 pipes are used in power generation and in downstream oil and gas, P5 and P9 grades are for refinery applications.

ALLOY PIPE A335

How to define alloy pipes?

Alloy pipes are tubular with higher percentages, than standard carbon steel pipes, of alloying elements as Molybdenum (Mo), Chromium (Cr), Nickel, etc. Actually, the ASTM A335 covers “low-alloy” steel pipes, i.e. pipes that have a total amount of alloying elements below 5%. The addition of higher percentages of alloying elements (example Nickel and Chromium) transforms the steel into higher alloys, like stainless steel, duplex, up to super-alloyed materials like Inconel, Hastelloy, Monel, etc.

Alloy steel pipes are used in the energy industry for high temperature and very low-temperature service (cryogenic), or for applications with very high pressures.

ASTM A335 alloy steel pipes fit ASTM A234 WPx series buttweld fittings (WP5, WP9, WP91) and A182 Fx forged fittings and flanges (A182 F5, F9, F11, F22, F91). All these materials have similar chemical and mechanical properties and can be joined or welded.

ASTM A335 P91 alloy steel pipes

Alloying elements

The addition of Molybdenum (“Moly”) increases the strength of the steel and its elastic limit, enhance the steel resistance to wear, its impact qualities, and the hardenability. It also improves the resistance to softening, makes chromium steel less prone to embrittlement and prevents pitting.

Chromium, a key element also for stainless steel alloys, prevents steel oxidation at elevated temperatures and increases the resistance of steel to corrosion. It enhances the tensile, yield, and hardness properties of low-alloy pipes at room temperatures.
Other alloying elements, present in various degrees in pipes of all grades are:
  • Aluminum: decreases oxygen from steelmaking
  • Boron: used to produce fine grain size and enhance steel hardness
  • Cobalt: used to enhance the steel’s heat and wear-resistance
  • Manganese: gives better steel hardenability
  • Nickel: Enhances toughness, hardenability and impact strength at low temperatures
  • Silicon: decreases oxygen, enhances hardenability and toughness
  • Titanium: prevents precipitation of chromium carbide
  • Tungsten: refines steel grain size and enhance the steel hardness, especially at high temperatures
  • Vanadium: gives steel enhanced fatigue resistance

As mentioned, low-alloy steels have a total amount of alloying elements below 5%; high alloy steel has a higher percentage of these elements.

A335 PROPERTIES

CHEMICAL COMPOSITION

The types of alloy steel covered by the ASTM A335 – ASME SA335 specification are designed with a “P” prefix, from P5 to P92. Grades P11/P22 and P91/92 are typically found in power stations, whereas grade P5 and P9 are more common for application in the petrochemical industry. Grades P9, P91 are, in the list, the more expensive (a P91 seamless pipe may cost approx 5€ per kg.).

ASTM A335
Low-Alloy Steel
(Grades)
UNS
equivalent
C≤MnP≤S≤Si≤CrMo
P1K115220.10~0.200.30~0.800.0250.0250.10~0.500.44~0.65
P2K115470.10~0.200.30~0.610.0250.0250.10~0.300.50~0.810.44~0.65
P5K415450.150.30~0.600.0250.0250.54.00~6.000.44~0.65
P5bK515450.150.30~0.600.0250.0251.00~2.004.00~6.000.44~0.65
P5cK412450.120.30~0.600.0250.0250.54.00~6.000.44~0.65
P9S504000.150.30~0.600.0250.0250.50~1.008.00~10.000.44~0.65
P11K115970.05~0.150.30~0.610.0250.0250.50~1.001.00~1.500.44~0.65
P12K115620.05~0.150.30~0.600.0250.0250.50.80~1.250.44~0.65
P15K115780.05~0.150.30~0.600.0250.0251.15~1.650.44~0.65
P21K315450.05~0.150.30~0.600.0250.0250.52.65~3.350.80~1.60
P22K215900.05~0.150.30~0.600.0250.0250.51.90~2.600.87~1.13
P91K915600.08~0.120.30~0.600.020.010.20~0.508.00~9.500.85~1.05
P92K924600.07~0.130.30~0.600.020.010.58.50~9.500.30~0.60

MECHANICAL PROPERTIES

Hardness
A335 Low-Alloy PipeUNS NumberYield Strength ksiTensile Strength ksiElongation %RockwellBrinell
P1K11522305530
P2K11547305530
P5K41545407030207 max
P9S50400306030
P11K11597306020
P12K11562326030174 max
P22K21590306030
P91K91560608520

TESTING REQUIREMENTS

  • Transverse/longitudinal: tension and flattening, hardness, bend tests- for material which has been heat-treated in batch furnaces, these tests shall be made on the 5% of the pipes from each heat lot number. For smaller lots, one pipe at a minimum has to be tested
  • ASTM A335 Gr. P91 shall have a hardness of 250 HB / 265 HV (25 HRC)
  • Hydro testing: shall be applied to every length of pipe
  • The non-destructive electric test is optional

TOLERANCES

DIAMETER

A335 PipeOverUnder
NPS [DN]in.mmin.mm
1/8 to 1 1/2 / DN 6 to 401/64 (0.015)0.41/64 (0.015)0.4
Over 1 1/2 to 4 / DN 40 to 1001/32 (0.031)0.791/32 (0.031)0.79
Over 4 to 8 / DN 100 to 2001/16 (0.062)1.591/32 (0.031)0.79
Over 8 to 12 / DN 200 to 3003/32 (0.093)2.381/32 (0.031)0.79
Over 12 / > DN 300+/- 1% of the specified outside diameter

WALL THICKNESS

The tolerances in WT, in %, from specified are:

  • 1/8 to 2 1/2 [6 to 65] incl., all t/D ratios: over 20%, under 12.5%
  • Above 2 1/2 [65], t/D < or = 5%: over 22.5%, under 12.5%
  • Above 2 1/2 [65], t/D > 5%: over 15%, under 12.5%

t = Specified Wall Thickness; D = Specified Outside Diameter)

 

ALLOY PIPE CROSS REFERENCE TABLE ASTM vs. EN GRADES

Chrome Moly Pipes: Werkstoff vs EN vs ASTM
Werkstoff /DINENASTM
1.541516Mo3A335 Grade P1
1.733513CrMo4-5A335 Grade P11, P12
1.738010CrMo9-10A335 Grade P22
1.7362X11CrMo5A335 Grade P5
A335 Grade P9
1.4903X10CrMoVNb9-1A335 Grade P91

ALLOY STEEL PIPE MANUFACTURERS

Pipe MillCountry  
Jiangu Chengde Steel Tube Co Ltd. LtdChina
ChomutovCzech
Eschweiller(Bentler)Germany
Vallourec TubesGermany, France, & Brazil
TenarisItaly, Mexico, & Argentina
Sumitomo MetalJapan
JFEJapan
Productos TubularesSpain
Tubos ReunidosSpain
Wyman GordonUSA
Michigan SeamlessUSA
Rockwell CollinsUSA

We recommend purchasing the ASTM A335 specification from the ASTM website or the IHS store to get a complete understanding of this topic.

Comments

This post currently has 9 responses

  • WE NEED FOR URGENT DELIVERY THE FOLLOWING A335 GRADE P11 PIPE:

    ITEM 1: SPEC 610.00MM X 9.53MM (DIAM 24″) SCHED 20/STD (ASME B36.10): 12 METERS
    ITEM 2: SPEC 914.00MM X 9.53MM (DIAM 36″) SCHED 20/STD (ASME B36.10): 12 METERS

    IMMEDIATE AVAILABILITY IS A MUST. PLEASE PROVIDE PRICE, DELIVERY AND COUNTRY OF ORIGIN (MATERIAL CERTIFICATES MUST BE INCLUDED IN PRICE).
    IF NEEDED, CALL ME AT 281-989-7259.
    THANK YOU!!

  • We need 2 each of IP By-Pass Pipe Spool,
    Dia: 30 inch, Wall Thickness: 25 mm,
    Material: A-335 Gr P91,
    Length: 1000 mm (Seamless pipe) with bevels, Fluid-Steam, Pressure-10 Bar, Temperature-574°C
    together with Data Sheet.
    Bid Closing date : 10th May, 2020.
    Delivery Terms: Ex- Works and CIF Doha, Qatar.

  • We urgently need 2 each of IP By-Pass Pipe Spool, Dia: 30 inch, Wall Thickness: 25 mm, Material: A-335 Gr P91, Length: 1000 mm (Seamless pipe) with bevels, Fluid-Steam, Pressure-10 Bar, Temperature-574°C, as per attached drawing, on or before 19th May, 2020.

    Delivery Terms : DDP Qatar/ CIF Doha Port/ Ex-Works(Provide Packing details with dimension)
    Also include all the following details when quoting.
    1. Packing charges
    2. Documentation charges.
    3. Datasheet.

Leave a Reply

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

Sidebar