A335 P9 pipes is a kind of chrome moly pipes (ASME S/A335, Chrome-Moly) listed in ASTM A335, which has become a standard in the power generation industry and the petrochemical industry, not only because of its tensile strength, corrosion resistance and high-temperature strength, but also because of its cost-effectiveness. Chrome Moly Pipes are popular in P-Grades P5, P9, P11, P22, P91 and P92. The most common use of grades P11, P22 and P91 is in the powder industry and petrochemical plants, Grades P5 and P9 are commonly used in refineries.
We stock a full range of the following A335 Chrome Moly Pipe grades
Sizes
1/4” Nominal to 24”O.D. Seamless Alloy Pipe
Wall Thickness – Schedule 40 through XXH
Chrome Moly Pipe Specifications & Grades
SA335 & A335 – Grades P5, P9, P11, P22, P91, P92
A691 1-1/4 Chrome through 9 Chrome (Welded Alternative to A335)
Chrome Moly Pipe Specification
A/SA335
NPS 1/4″ – 24″
Schedules 40 through 160, STD, XH and XXH
A335 P9 Pipes Dimensions
A335 P9 Pipes Weight
Scope
This specification covers nominal wall and minimum wall seamless ferritic alloy-steel pipe intended for high-temperature service. ASTM A335 pipe ordered to this specification shall be suitable for fusion welding, bending, flanging (vanstoning), and similar forming operations.
Material & Manufacture
Pipe may be either hot finished or cold drawn with the finishing heat treatment noted below.
Heat Treatment Requirements
P5, P9, P11, and P22
Grade Heat Treatment Type Normalizing Temperature Range F [C] Subcritical Annealing or Tempering
Temperature Range F [C]
P5 (b,c) Full or Isothermal Anneal
Normalize and Temper ***** 1250 [675]
Subcritical Anneal (P5c only) ***** 1325 – 1375 [715 – 745]
P9 Full or Isothermal Anneal
Normalize and Temper ***** 1250 [675]
P11 Full or Isothermal Anneal
Normalize and Temper ***** 1200 [650]
P22 Full or Isothermal Anneal
Normalize and Temper ***** 1250 [675]
P91 Normalize and Temper 1900-1975 [1040 – 1080] 1350-1470 [730 – 800]
Quench and Temper 1900-1975 [1040 – 1080] 1350-1470 [730 – 800]
A335 P9 Pipe Chemical Requirements
Grade P-5 P-9 P-11 P-22 P-91 P-91 shall also include the following:
Element UNS Designation K41545 S50400 K11597 K21590 K91560
Carbon 0.15 max 0.15 max 0.05 – 0.15 0.05 – 0.15 0.08 – 0.12 V at 0.18 – 0.25
Manganese 0.30 – 0.60 0.30 – 0.60 0.30 – 0.60 0.30 – 0.60 0.30 – 0.60 N at 0.030 – 0.070
Phosphorous, max 0.025 0.025 0.025 0.025 0.020 Ni at 0.40 max
Sulfur, max 0.025 0.025 0.025 0.025 0.010 Al at 0.02 max
Silicon 0.50 max 0.25 – 1.00 0.50 – 1.00 0.50 max 0.20 -0.50 Cb at 0.06 – 0.10
Chromium 4.00 – 6.00 8.00 – 10.00 1.00 – 1.50 1.90 – 2.60 8.00 – 9.50 Ti at 0.01 max
Molybdenum 0.45 -0.65 0.90 – 1.10 0.44 – 0.65 0.87 – 1.13 0.85 – 1.05 Zr at 0.01 max
A335 P9 Pipe Mechanical Properties
Seamless
P-5 P-9 P-11 P-22 P-91 P91 shall not have a hardness not exceeding 250 HB/265 HV [25HRC].
Tensile Strength, min., psi
ksi 60 60 60 60 85
MPa 415 415 415 415 585
Yield Strength, min., psi
ksi 30 30 30 30 60
MPa 205 205 205 205 415
Permissible Variation in Wall Thickness
NPS [DN] Designator Tolerance, % from Specified
Over
Under
1/8 to 2 1/2 [6 to 65] incl., all t/D ratios
20.0%
12.5%
Above 2 1/2 [65], t/D < or = 5%
22.5%
12.5%
Above 2 1/2 [65], t/D > 5%
15.0%
12.5%
(t = Specified Wall Thickness; D = Specified Outside Diameter)
Elongation Requirements
Calculated Minimum Elongation Values
Elongation in 2 in. or 50 mm, min %
Wall Thickness P5, P9, P11, P22 P91
in. mm Longitudinal Transverse Longitudinal
5/16 (0.312) 8 30 20
20
9/32 (0.281) 7.2 28 19
19
1/4 (0.250) 6.4 27 18
18
7/32 (0.219) 5.6 26
17
3/16 (0.188) 4.8 24
16
5/32 (0.156) 4 22
15
7/8 (0.125) 3.2 21
14
3/32 (0.094) 2.4 20
13
1/18 (0.062) 1.6 18
12
Permissible Variations in Outside Diameter
Outside Diameter at any point shall not vary from standard specified more than:
NPS [DN] Designator Over Under
in. mm in. mm
1/8 to 1 1/2 [6 to 40], incl. 1/64 (0.015) 0.40 1/64 (0.015) 0.40
Over 1 1/2 to 4 [40 to 100], incl. 1/32 (0.031) 0.79 1/32 (0.031) 0.79
Over 4 to 8 [100 to 200], incl. 1/16 (0.062) 1.59 1/32 (0.031) 0.79
Over 8 to 12 [200 to 300], incl. 3/32 (0.093) 2.38 1/32 (0.031) 0.79
Over 12 [300] +/- 1% of the specified outside diameter
Mechanical Tests Specified
Transverse or Longitudinal Tension Test and Flattening Test, Hardness Test, or Bend Test
For material heat treated in a batch-type furnace, tests shall be made on 5% of the pipe from each treated lot. For small lots, at least one pipe shall be tested.
For material heat treated by the continuous process, tests shall be made on a sufficient number of pipe to constitute 5% of the lot, but in no case less than 2 pipe.
Notes for Hardness Test: P91 shall not have a hardness not exceeding 250 HB/265 HV [25HRC].
Notes for Bend Test: For pipe whose diameter exceeds NPS 25 and whose diameter to wall thickness ratio is 7.0 or less shall be subjected to the bend test instead of the flattening test.
Other pipe whose diameter equals or exceeds NPS 10 may be given the bend test in place of the flattening test subject to the approval of the purchaser.
The bend test specimens shall be bent at room temperature through 180 without cracking on the outside of the bent portion.
The inside diameter of the bend shall be 1 inch [25 mm].
Hydrostatic Test Each length of pipe shall be Hydro tested, at option of manufacture, nondestructive electric testing can be used.
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