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ASTM A335 Seamless Ferritic Alloy-Steel Pipe for High-Temperature Service

ASTM A335 Chrome Moly Pipe

ASTM A335 Seamless Ferritic Alloy-Steel Pipe for High-Temperature service. Pipe ordered to this specification shall be suitable for bending, flanging, and similar forming operations, and for fusion welding.  Sometimes referred to as P Grade, chrome moly pipe is popular in P-Grades P5, P9, P11, P22, and P91.  The most common use of grades P11, P22, and P91 is in the power industry and petro-chemical plants, Grades P5 and P9 are commonly used in refineries. 

A335 is often called chrome moly pipe because of the chemical makeup of Molybdenum (Mo) and Chromium (Cr). Molybdenum increases the strength of steel as well as the elastic limit, resistance to wear, impact qualities, and hardenability.  Moly increases the resistance to softening, restrains grain growth and makes chromium steel less susceptible to embrittlement.  Moly is the most effective single additive that increases high temperature creep strength.  It also enhances the corrosion resistance of steel, and inhibits pitting.  Chromium (or chrome) is the essential constituent of stainless steel.  Any steel with 12% or more Chrome is considered stainless.  Chrome is virtually irreplaceable in resisting oxidation at elevated temperatures. Chrome raises the tensile, yield, and hardness at room temperatures.  The composition chrome moly alloy steel pipe make it ideal for use in power plants, refineries, petro chemical plants, and oil field services where fluids and gases are transported at extremely high temperatures and pressures.  

Grades: P-5, P-9, P-11, P-22, and P-91

Sizes

NPS 1/4'' to NPS 48'' 

Wall Thickness - Schedules 10 through 160, STD, XS, XXS. 

Unscheduled heavy wall pipe thicknesses available up to 4 inches.  

Mechanical Properties
 

                                                Grade P11, P22, P5, P9                    Grade P91

Tensile strength, min, psi, (MPa)     60,000 (415)                                        85,000 (585) 

Yield strength, min, (MPa)            30.000 (205)                                        60,000 (415)

(Note: This is summarized information from ASME Specification A335. Please refer to the specific Standard or Specification or contact us for more details.)

Permissible Variations in Diameter

For pipe ordered to NPS or outside diameter, variations outside diameter shall not exceed those specified following:

NPS Designator              Over                    Under

                         In.      mm                 In.      mm

1⁄8to 11⁄2, incl.          1⁄64 (0.015) 0.40             1⁄64 (0.015) 0.40

Over 11⁄2 to 4, incl.      1⁄32 (0.031) 0.79             1⁄32 (0.031) 0.79

Over 4 to 8, incl.        1⁄16 (0.062) 1.59              1⁄32 (0.031) 0.79

Over 8 to 12, incl.       3⁄32 (0.093) 2.38              1⁄32 (0.031) 0.79

Over 12 6 1 % of the pacified outside diameter

For pipe ordered to inside diameter, the inside diameter shall be not vary more than 1 % from the specified inside diameter.

Packing: Bare packing/bundle packing/crate packing/wooden protection at the both sides of tubes and suitably protected for sea-worthly delivery or as requested.

Inspection and Test: Chemical Composition Inspection, Mechanical Properties Test(Tensile Strength, Yield Strength, Elongation, Flaring, Flattening, Bending, Hardness, Impact Test), Surface and Dimension Test, No-destructive Test, Hydrostatic Test.

Surface treatment: Oil-dip, Varnish, Passivation, Phosphating, Shot Blasting.
Both ends of each crate will indicate the order no., heat no., dimensions, weight and bundles or as requested.