Valve component built to NACE MR0175

[eng99]

We are currently building a valve to API 6A and NACE MR0175-2003. This valve has an internal part that is a nonpressure-containing (but pressure-controlling) component. The part is loaded only with a compressive load; therefore, there is no tensile stress in the part, only a compressive stress.

Section 1.4 states that NACE is applicable to "total tensile stress (applied plus residual)". Since our part only has a compressive stress, it doesn't have to meet NACE MR0175.

Is this a correct assumption?

 

[MikeHalloran]

I don't think so.

Depending on the shape of the part, it's entirely possible for a compressive load to produce a tensile stress.



Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA

 

[SJones]

What material is the part made from so that the specific requirements from ISO 15156 can be determined. If it is simply hardness control what will be the problem in achieving it for very little cost and less hassle with the purchaser?

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdo/