Replacement of material from A-216 WCB to AISI 4140 or AISI 1022

[Eabrar]

Hi

We want to replace valve body of material A 216 WCB with locally fabricated/machined valve body of AISI 4140 or AISI 1022 material. These valve body are machined from round bars and flanges are welded to the valve body.

I want to know the following:

1. Can we use AISI 4140 or AISI 1022 as pressure parts.
2. Is welds of these material are allowed as pressure welds.
3. Is there any company using the same material for valve body ( Machining valves body from round bar).

Best regards

Abrar

 

[metengr]

What is your intended application? The A 216 WCB is an ASTM Specification for Steel Castings, Carbon, Suitable for Fusion Welding for High-Temperature Service containing about 0.30% C and other residual elements that provide a minimum ultimate tensile strength of 70 Ksi and yield of about 36 Ksi.

In lieu of using AISI Type 1022 or low alloy 4140, I would suggest using the following standard to fabricate the valve body;

A 266 - Specification for Carbon Steel Forgings for Pressure Vessel Application. Grades 1 or 2 would be about the equivalent in terms of chemical composition and to A 216 Grade WCB. Carbon steel flanges for welding to the fabricated valve body could be purchased under an A 182 specification.

The AISI Type 1022 is too low in carbon content, and the AISI Type 4140 is low alloy steel, which could pose some added problems for welding. The A 266 Grade 1 is carbon steel with about 0.30% C, is readily weldable, and is an ASME Code approved material.

 

[arunmrao]

What size and class are the valves? Why do you need to machine from a bar stock when cast valves are readily available? Is it not possible to do away with the flanges and have a socket weld type of joint.?