FE Testing 1

[jaffaotc]

Experts,
can some one advce about the FE testing tools, if we want to carry a test what sort of tools & equipment required?

Jaff

 

[reverman]

Do you have CAD software? most modern CAD/solid modeling programs, Auto-CAD, UG, solidworks etc.. have FE capabilities or add-ins you can get.

 

[jaffaotc]

reverman.

its a fugutive emission test, i am talking about, can u bried what is the relation between in fugutive emission test and CAD software.

jaff

 

[reverman]

sorry thought you meant Finite element analysis

 

[reverman]

what kind of fugitive emission testing are you doing? testing a packing, testing a gasket? or testing packing in a valve?

 

[zdas04]

I thought you were talking about the Fundamentals of Engineering test and wondered why you had posted in "Valves".

As reverman says, there are a number of fugitive emissions tests that can be applied. Most of them are some variant of a "bag test" where you seal a bag of some sort around the place you are testing and time how long it takes to fill the bag (of known volume) to a specified pressure. This is easy when you're trying to quantify leakage past a vent valve.

Quantifying flange/thread leakage, or packing leakage can be a challenge because it can be difficult to get a seal around complex shapes.

David

 

[reverman]

API 622 provides details on how to build a test fixture to test packing.

As far as testing valves unfortunately there is no one standard. I would try and get a copy of either chevron's fugitive emission testing procedure Or Lion Oil's those two specs are the most harsh I've seen and if you pass those you many companies (not all) will accept it.

API 622 is currently in revision and one of the items on the agenda was to add a method for testing valves. However at the last API meeting this section was removed. They may release as a separate API standard but I have no idea what time frame that would be.

 

[NGiLuzzu]

First of all get a good NDT training course on Leak Testing (LT/MSLT method) according to EN 473 and/or ASNT-TC-1A standards, for example.

Then check EN 1779 and ISO 15848-1 (Annex A and Annex B) for an overview of the possible techniques, for both general applications and valve (type and production) testing.

In the end, you should be able to choose a mass spectrometer helium leak detector capable of fulfilling Your needs and the relevant accessories.

Finally search this Forum for all the related discussion threads...



Hope this helps,
'NGL
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[jaffaotc]

Thanks to all.

but i was wondering that API-622 was already released or not, i was searching for that standard.

jaff

 

[NGiLuzzu]

Jaff,
searching on

http://www.api.org/Publications/,

You can find that API 622 standard about TYPE TESTING OF PROCESS VALVE PACKING FOR FUGITIVE EMISSIONS is currently pubblished in Edition 1 dated 2006.

Please note that "... This standard does not provide acceptance criteria for valve packing, nor is it intended to replace proof testing of valve assemblies or valve production testing...".
Hence, I believe that the application of such standard is up to Packing Manufacturers in order to qualify their products, and not up to Valve Manufacturers; Valve Manufacturers may specify that as a requirement when they buy packings, but should not be considered accountable and liable for the execution of the relevant tests.


See also:

- thread408-155734;

- thread408-253784;

- thread408-261665...



Hope this helps, 'NGL


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[HitokiriAoshi]

Anegri's suggestion on a helium sniffer is the most realistic method of testing for applications where you can fill the valve with helium. If that cannot be done, you will have to resort to bag method or specialized sniffer if the medium in the pipeline is detectable in ppm.

I work at a valve manufacturing facility and we only perform emmision tests for PO's that requires a testing specified by the customer, and normlly only one valve for a whole PO at that. Otherwise the testing equipment is used primarily to look pretty and to test valve for AML certificate for other end-users. The packing emmision test is a long and annoying process that involves mechanical and thermal cycling along with a very poor fellow sitting there with a stick... (sniffer)

Frankly, some of the new standards being developed are almost borderline impossible from the viewpoint of valve manufactures requiring below 75 ppm in vaccum throughout the test... while refusing to pay more for it.

I'm not too sure on the exact situation on the floor in the plants, but I am sure they get valves to pass inspection by tightening the packing gland more and/or getting more expensive packings during maintence.

-Sniper out