Introduction To ASTM A135 ERW Steel Pipe

ASTM A135 is the standard specification for NPS 2 to NPS 30 [DN 50 to DN 750] ERW (electric resistance welded) steel pipe used for conveying gas, steam, water, or other liquids. This standard is primarily used for pipes that are designed for low-pressure applications, such as in fire protection systems, as well as general plumbing and mechanical applications. Here's an introduction to ASTM A135 ERW steel pipe.

Chemical Composition of ASTM A135 ERW Steel Pipe:

Mechanical Properties of ASTM A135 ERW Steel Pipe:

Manufacturing and Heat Treatment:

Whether it's an ASTM A135 Grade A or Grade B ERW steel pipe, these pipes are typically produced using the high-frequency resistance welding process. They are manufactured through resistance welding or induction welding using single or continuous lengths of flat steel (plate) without the introduction of any extraneous materials. In other words, no filler metal is necessary. Welds on ERW pipes conforming to ASTM A135 Class B should undergo heat treatment after welding, ensuring they reach a minimum temperature of 1000°F [540°C] or an equivalent treatment that eliminates any untempered martensite.

Surface Condition and End Preparation:

ASTM A135 ERW steel pipes should exhibit a reasonably straight profile and be devoid of defects. Surface imperfections that exceed 12.5% of the nominal wall thickness should be avoided. These pipes can be supplied with plain, beveled, or threaded ends, with the exception that ERW pipes provided in SCH 10 are exclusively furnished with plain ends. All residual internal and external protrusions resulting from cutting processes should be removed. Additionally, each section of threaded pipe must be equipped with a fitting for connection.

Inspection and Testing of ASTM A135 ERW Steel Pipe:

- Chemical analysis

- Tensile test

- Dimensional inspection

- Visual inspection

- Hydrostatic test

- Flatten test

- Non-destructive testing (NDT)