It means a valve approved by your client, whoever your client is, not just a valve that has been approved by Shell or BP or ExxonMobile, etc.  Many clients have a preapproved vendor and manufacturer list for which you should choose only the valves or equipment offered by companies that are on that list.  If preapproved items are to be used on your project, your client should provide you with a such a list in advance.

Alternately, you may see that phrase on a drawing or specification in reference to a particular item.  If that is the case, it indicates that you should get the client's specific approval for that item (ususally in writing) before actally making the order or final purchase.  

If you have any further doubts as to what that actally means you should do about it, you should seek specific direction from your contract, engineering, purchasing department supervisors.

BigInch is correct.  More can be said about some details.

Often companies like Shell, BP and Exxon have a list of approved manufactureres.  However, the refinery group may approve the a subset of the gate valves; the upstream group may approve a subset of the ball valves and the petrochem group may specify a specialty valve instead of a standard model project.  This could all apply to the same corporate line specification - valve list.

Each control valve and many of the line class block valves may be selected based upon the service.  The companies mentioned may have as many engineers involved in the project representing the various interests as the contractor specifying and buying the valves.  A reliability engineer, maintenance and operations may represent the plant while a corporate engineer represents the project.

So how is the saleswoman for the valve manufacturing group to cope?  Knowledge of the market requirements, as well as free lunch seminars and training could help.  Besides the valve details, some of these are industry segment issues, all are people issues.

Know the people who are specifying and approving the valves.

Thanks Biginch and JLSeagull! make sense.

I found that BS6364 and SHELL MESC77/306 have tightly relationship with Fugitive Emission Tests. Does it mean "approved" valve is manufactured according to MESC standard? and every valve manufacturer who implement MESC in their producing process will automatic named as SHELL "approved" valve.

7431,
            BS 6364 standard (Appendix A) and Shell MESC SPE 77/306 specification apply to cryogenic or low temperature testing of valves; such testing is related with Fugitive Emissions only because external leakage testing is required (in addition to seat leakage measurements).
            Please take a look at thread408-148535 and thread408-81124 within this site.

            Documents directly related to Fugitive Emission tests are ISO 15848-1 and ISO 15848-2 standards, Shell MESC SPE 77/312 specification, German TA-Luft regulation and VDI 2440 standard, American EPA 21 method, etc...  
            Please take a look at thread408-64093, thread408-143739, thread483-143737, thread408-48808 and thread408-155734 within this site.  

            It must be observed that many times, for this kind of tests, distinction is made between type testing (deeper and intended to qualify a product design) and  production testing (quicker and intended to control the products quality consistency among different lots)... even if the Specifiers themselves make confusion between the two and the relevant scopes.   

            As said above, every Customer may have its own protocol or strategy to qualify a valve Manufacturer and/or a valve design. In addition to documentation showing Company's Quality System, experience and references, compliance with design codes and calculation methods, drawings, etc..., different Customers may state different testing requirements.
            Some of them ask for "trial valves" to test them on their own in particular services and carry out a benchmark among different valves.
            Other ones may stress the documental aspect; or, on the other hand, may force the Manufacturer to perform type qualification tests at its facilities in order to place the purchase orders...   


Hope this helps,           'NGL

anegri. Nice post.

BigInch,     thank you!

            It is also interesting what you and JLSeagull say; in particular about the different requirements coming from the same Company. If that may be justified for an End User by the different service conditions in the different locations of the plants, that is less justifiable from different projects WorkGroups of the same Engineering Company dealing with the same application (i.e. cryogenic and/or low temperature service, hazardous fluids, etc.).

            On the other hand, some big Groups try to centralize the specification and qualification work in a single Business Unit: this is the case of Shell and Shell Global Solutions International (http://www.shell.com/home/Framework?siteId=globalsolutions-en), for example.
            But unfortunately, as far as I can see from a valve Manufacturer standpoint, this one is not an example to imitate!! In fact, it seems that the information exchange between  SGSI and the Shell plants all over the world is very poor; SGSI Representatives seem to be Inspectors interested in the witnessing fee, more than Engineers with specific technical expertise about valves; they seem keen on the figures written on paper (standards and spec's) only and far from the down-to-earth plant reality; hence it is not strange to see how every new or old Shell project worldwide adopts its own rules with little or no regard to SGSI authority.
            So a valve Manufacturer may be forced to carry out a long and expensive campaign of type tests having little or no technical meaning with reference to the actual service conditions and to generously pay SGSI for witnessing them, without any guarantee about the return on such investment!!     

            In my opinion, the approach sometimes adopted by other big Companies (BASF, Siemens, Bayer, etc.) is more correct: they just ask to provide one or more valves for a certain service and then they perform all the test they want, in the Laboratory and/or on the plant.
            So they should avoid to run after exaggerated (sometimes infeasible) performances just because they're required by a piece of paper; they may simply choose the best valve in the market for that service!

            Sorry if I went a little off-topic; I hope the discussion remains interesting anyway...

Thanks and Regards,           'NGL

Anegri, Thank you very much!

Another reason for "approved" lists, for example, valves, is to minimise warehouse inventory and to make life easier for the service guys.

Many of my clients standardise on certain manufacturer, but also on ANSI classes. For example, some will onl use ANSI 600 and up.

The reason is that it makes life easier for service guys. They go to a job site, and bring a 2" 300# Nutron valve, only to discover they need a 2" 150" KF valve.

By standardizing on 2" 600# KF Series F valves, this is less likely.

"Do not worry about your problems with mathematics, I assure you mine are far greater."   
Albert Einstein
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