A335 Chrome Moly Pipe, Fittings, & Flanges

A335 pipe, valves,  fittings, and fasteners are referred to as Chrome Moly Pipe.  Its applications include, but are not limited to, the power generation and petrochemical industry.  A335 pipe, valves,  fittings, and fasteners are a cost-effective path for achieving tensile strength, corrosion resistance, and high-temperature strength. 

Ordering Information

The following will need to be specified when ordering A335 pipe, valves,  fittings, and fasteners.

Characteristic What to Specify
Quantity Feet or number of lengths
Size NPS (Outside Diameter) and Schedule Number (Average Wall Thickness)
Grade Grade A, Grade B (most common), or Grade C
Coating Bare, Black, FBE, etc
Manufacturer Approved Manufacturer List (AML), or Country of Origin restrictions

 

Manufacturing Considerations

Outside Diameter Requirements

NPS [DN] Designator  Over Under
in. mm in. mm
1/8 to 1 1/2 [6 to 40], incl. 1/64 (0.015) 0.4 1/64 (0.015) 0.4
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

 

Wall thickness requirements

NPS [DN] Designator  Tolerance, % from Specified
Over Under
1/8 to 2 1/2 [6 to 65] incl., all t/D ratios 20.00% 12.50%
Above 2 1/2 [65], t/D < or = 5% 22.50% 12.50%
Above 2 1/2 [65], t/D > 5% 15.00% 12.50%
(t = Specified Wall Thickness; D = Specified Outside Diameter)

 

Grades

Grades P-11, P-22 - P-91 & P-92 are prevalent grades for the power industry, while P-5 & P-9 are the major refinery processing grades utilized.

   

C

Mn

P (max %)

S (max %)

Si

Cr

Mo

Grade UNS Designation 0.15
max
0.30 –
0.60
0.025 0.025 0.50
max
4.00 –
6.00
0.45 –
0.65
P-5 K41545 0.15
max
0.30 –
0.60
0.025 0.025 0.25 –
1.00
8.00 – 10.00 0.90 –
1.10
P-9 S50400 0.05 –
0.15
0.30 –
0.60
0.025 0.025 0.50 –
1.00
1.00 –
1.50
0.44 –
0.65
P-11 K11597 0.05 –
0.15
0.30 –
0.60
0.025 0.025 0.50 max 1.90 –
2.60
0.87 –
1.13
P-22 K21590 0.08 –
0.12
0.30 –
0.60
0.02 0.01 0.20 – 
0.50
8.00 –
9.50
0.85 –
1.05

 

Mechanical Requirements

 Grade Tensile Strength, min., psi Yield Strength, min., psi
  ksi MPa ksi MPa
P-5 60 415 30 205
P-9 60 415 30 205
P-11 60 415 30 205
P-22 60 415 30 205
P-91 85 585 60 415

 

Testing Requirements

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.

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.

 

Manufacturers

Pipe

Manufacturer

Country

Vallourec Tubes

Germany, France, & Brazil

Productos Tubulares

Spain

Sumitomo Metal

Japan

JFE

Japan

Tenaris

Italy, Mexico, & Argentina

Wyman Gordon

USA

Michigan Seamless

USA

Tubos Reunidos

Spain

Rockwell Collins

USA

Jiangu Chengde Steel Tube Co Ltd. Ltd

China

Eschweiller(Bentler)

Germany

Chomutov

Czech


 

MSI Supply can also supply chrome moly (A234 P grades) fittings and flanges.  Various manufacturers MSI offers are listed below.

Butt Weld Fittings

Manufacturer

Country

Ameriforge

USA

Canadoil Forge

Canada

Custom Alloys

USA

Dynamic Products

USA

Erne

Austria

IBF

Italy

LA Boiler Works

USA

Petrol Raccord

Italy

Shaw APP

USA

SK Bend

Korea

T.K Corp

Korea

Taylor Forge

USA

TFA

USA


 

Flanges

Manufacturer

Country

Ameriforge

USA

Bebitz

Germany

DL Flange

USA

Galperti

USA & Italy

Maass

USA & Germany

Metalfar

Italy

Newman Flange

USA

Western of Texas

USA

Kumwoo

Korea


 

O-lets

Manufacturer

Country

CGP

USA

Bonney Forge

USA

IML

Italy

Kumwoo

Korea

Mega

Italy

Penn Machine

USA

SK Bend

Korea

Viar

Italy