ASTM A335 Pipe (ASME S/A335, Chorme-Moly) is a seamless ferritic Alloy-Steel Pipe for high temperature service. Pipe ordered to this specification shall be suitable for bending, flanging (vanstoning), and similar forming operations, and for fusion welding. Sometimes referred to as “P Grade”, chome 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.
Federal Steel Supply stocks a full range of the following A335 pipe grades:
Grades: P-5, P-9, P-11, P-22, and P-91
NPS 1/4” to NPS 48”
Wall Thickness – Schedules 40 through 160, STD, XS, XXS.
Unscheduled heavy wall pipe thicknesses available up to 4 inches.
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.)