ASTM A335 P5, P9, P11, P22, P91 Pipes

ASTM A335 pipe (with Grade P5, P9, P11, P22, P91 pipes) know as Chrome-Moly Alloy Pipe, has been widely used in different industries for high temperature, high pressure services. According to market data, it is one of the most consumption alloy pipes in boiler industry, heat exchanger, power station, high and super high pressure vessels. 

What is ASTM A335 pipe?

We also call ASTM A335 pipe as ASME S/A335 Chrome-Moly pipe, it is a type of seamless pipe could be used in high temperature environments of 540 – 750 °C.

The A335 pipes are generally called chrome moly pipe as they have a high level of Chromium and Molybdenum presence in it. While Molybdenum increases the overall strength, resistance, elasticity, hardenability and overall quality, moly ensures that the material is more resistant to softening, restrains the growth of grains and lessens the chances of embrittlement. It is the single additive that is responsible for the increase in high temperature resistance and it also improves the corrosion resistance to steel.

Key Elements Chromium for this pipe

Chromium is a key component that is used in the manufacture of stainless steel. If the chromium levels are above 12%, it can be classified as stainless steel. The oxidation resistance potential of chrome is irreplaceable even in elevated temperatures. The hardness, tensile and yield strength is better at standard temperatures. Due to the composition of the material, it is ideal to be used in power plants, refineries, petro-chemical plants and other oil field services when there is transportation under high temperatures and pressures involved.

ASTM A335 Standard Specification and Scope

In ASTM international associates defines: “ASTM A335 is the standard specification for seamless Ferritic Alloy-Steel Pipe for High Temperature Service.” This specification covers nominal wall and minimum wall thickness pipe that with alloy material and manufactured in seamless type. The pipe under this specification shall be suitable for bending, flanging, and all the other similar processing and formations. Although it shall be good for fusion welding.

Therefore, ASTM A335 pipe material also could be used to manufacture pipe fittings like elbow, tee, reducers etc.