What is the manufacturing process of ASTM A234 WPB pipe fittings?

The WPB is not short hand for any process. It is simply an identifier developed by ASTM. The fittings in question are manufactured in the same manner as the companion pipe for this specification.

ASTM A234 WPB pipe fittings

In very large sizes, the fittings may be manufactured in pieces and welded together as is the case for many large fittings.

The term used for the manufacturing is called “wrought” which means it is worked as opposed to being cast or forged.

As to the W standing for weldable, I’m not sure that is correct since that are many, many pipe fittings that are weldable but carry designations other than a W. Note the reference below.

Forging is the manufacturing process of ASTM A234 WPB pipe fittings.

W = WELDABLE / wrought
P = RELATED TO P NUMBER OF ALLOY MATERIAL
B = REFER TO MINIMUM YIELD OF MATERIAL

LATEST STANDARD IS:

ASTM A234/A234M-07
Standard Specification for Piping Fittings of Wrought Carbon Steel and Alloy Steel for Moderate and High Temperature Service

This standard covers wrought carbon steel fittings of seamless and welded construction which are manufactured to the dimensional specifications of ASME B16.9 and B16.28. These fittings are primarily for use in pressure piping and in pressure vessel fabrication for service at moderate and elevated temperatures.

---

Carbon steel pipe fittings production process

Buttweld Fittings manufacturing process includes a series of steps like Annealing, Straightening, Pickling & Passivation and Polishing.

How a Butt Weld Fitting is Made?

A butt weld pipe fitting is made by the process of hot forming that includes bending and forming to shape. The starting material of butt weld fitting is a pipe that is cut to length, heated and molded into specific shapes by means of dyes. Heat treatment is also done to remove residual stresses and obtain desired mechanical properties.

These fittings are produced using latest technology, ensuring excellent strength and long service life. The process needs a lesser amount of heat treatments to ensure better physical properties.

The series of steps involved in the manufacturing Process of Buttweld Fittings are given in a detailed view below:

Annealing :

Annealing is also known as heat treatment, which plays an active role in the production. In this step, the tubes are carried out in fully automated and conveyor to heat them at certain temperature. Once the tubes get heated, they immediately quench in water.

Straightening :

The tubes are straightened with the help of straightening machine to provide a high degree of straightness in this step.

Pickling :

The process of Pickling refers to the removal of high temperature scale and adjacent low chromium layer of metal from the surface of stainless steel.

Passivation :

Passivation is the process of treating the surface of stainless steels in order to eliminate the contaminants from the metal. The process also helps in promoting the formation of a continuous passive film on a freshly created surface.

Polishing :

The final step, is named as Polishing that reflects the wonderful quality, high aesthetic & hygienic value and high durability of buttweld fittings. Polishing is a essential step to gain excellent features for meeting the varied demands of clients.