Radio graphic Test (RT) and Magnetic particle Test (MT) 1

[hasanmoulana]

I have a requirement of 10" gate valve WCB, Class 300, Trim 1. My client requires Radio graphic Test (RT) and Magnetic particle Test (MT) to be carried out on the valves during the manufacturing process. But my manufacturer is informing that only Radio graphic Test (RT) can be carried out on the valves & Magnetic particle Test (MT) is not required for this valve. I have a doubt. Can any one inform me if it is true.

 

[gerhardl]

If you do not have done it already:

Get your end-user to specify exactly, or agree with client/end user, what rules/paragraphs/procedures/instructions it is referred to. It is necessary to agree in detail on what parts are expected going to be tested, and to which procedures and which results/passing qualifications you are expected to have.

Cross-check same with maqnufacturor and ask for the reason magnetic particle test can not be used. (Material reasons?)

Testing details discussions are not uncommon, and normally a result of generalization or repetition of earlier procedures or routines not suitable for the particular product.

Misinterpretation can be at either side, even yours.....

 

[bcd]

The customer defines the requirements. Is it possible to radiograph a 10" WCB gate valve body? YES. Is it possible to magnetic particle test? YES. But as gerhardl mentions, to what standard and what is the acceptance criteria? Is it ASME B16.34 for the standard and acceptance criteria?

 

[hasanmoulana]

Dear bcd (Mechanical),

Many thanks for your valuable suggestion. Yes, acceptance criteria is as per ASME B16.34. Please send your valuable suggestion. A local testing lab is informing that they can carry out RT/MT on our stock valves. They informed that they will dismanle the valve, carry out NDE & assemble the valve again. Is this procedure acceptable. I have a doubt that the testing lab might damage the internal parts while dismantling & reassembling. Please send your suggestion as to how to proceed further.

 

[reverman]

To RT the valves properly they will most likely need to be dis-assembled.

If you are not the manufacturer of the valves I would suggest you contact the manufacture before dis-assembly. typically this action can void the warranty.

also it's important that gate valves be assembled properly. flipping the wedge will cause the valve to leak.

 

[bhollands]

MT testing to ASME B16.34 is very common for WCB valves. I am probably too late to help but if this is a finished valve be sure that your lab using a Yoke method and not prods. The arc strikes that you may get from the prods could cause problems on the finished machined surfaces.

Bob