Selection of on-off valves based on API/ASME/BS stds 1

[Lena1183]

Hi all! Request ur help in selection of valves based on design standards? For ex, if we consider gate, globe and check valves,design stds shall be as per API or ASME. I need to know how the piping engineer is mentioning that the particular GGC should meet the requirements of API 600 or BS stds or ASME B16.34 only, inspite of the function it performs being the same, irrespective of the design standards.Does the design standard play a vital role here? If gate valve is taken, API 600 gate valves is for wedge / ASME B16.34 is for PSGV gate valves. Based on what it is decided to be a wedge or PSGV type. Can we promote our design by taking deviation & quote, if any of the other type design is not in our scope of supply. Request your feedback...? Tks in advance...!

 

[gerhardl]

Hello Lena 1183

You are asking:... 'Can we promote our design by taking deviation & quote, if any of the other type design is not in our scope of supply?

Technically the answer could be yes if the valves for all purposes are equal in performance for use and required limits and tests.

However I suspect that in end your question is a commercial one: 'How likely is it that we will win or get a contract acepted with deviations on the giving secifications for the project?'

The answer is usually that the chances are small and not worth the effort to try.

The valve market is not less fierce than other technical markets. Competitors able to supply to a given (sensible, commercially available) specification is always present!

Try at least to communicate the deviations and your arguments to select your valves and ask if such an offer would be technically or commercially interesting and would be evaluated if you should offer this way, before you make the effort of a detailed bid.

 

[Lena1183]

Tks gerhardl for your views. But my main query is not in taking deviation & quoting. I would like to know how the piping engineer decides tat the particular on/off valve should be as per either API/ASME stds. Watever be the standards, the function it performs remains the same right. So why is tat they r mentioning the stds shud be as per either API or ASME or BS. Could any of u comment on this pls ?

1ce again Tks gerhard.

 

[rneill]

Due to historic development of different standards they tend to be tailored to specific types of valves and thus may provide a more thorough set of requirements for a given valve design than might another standard.

In addition, in some cases the standards writing body may have their own bias so the standards written by that organization may be more focused on mechanical robustness or may have more details supporting serviceability and long term performance.

ASME B16.34 for example is a broad based standard that can be generally applied to all types of valves that will ensure mechanical safety but it may not provide the same details with regards to gate valve design that API 600 might provide as it is specifically focused on gate valves. End users might therefore prefer to specify API 600 in order to ensure compliance with additional functional and service requirements that might perhaps not be in the ASME B16.34 standard. For example, API 600 provides standard trim code descriptions for gate valves whereas ASME B16.34 does not (just one example).

In other cases, the design code may list only certain valve standards and so the purchaser is specifying the valves based upon the design code in use.

Sometimes, while industry practice has been to specify one standard for valve design, another design standard may evolve and incorporate new requirements resulting in a gradual migration from one to the other. However, when this happens it may takes years (or decades) before the transition is complete as many end users don't update their specifications frequently or may not initially be aware of the change.

 

[gerhardl]

OK, let me try, but also state that this is purely my own opinion, as seen from Scandinavia/Northern Europe!

First, if starting with 'the helicopter view' both piping and integrated valves are always part of a larger system, including other machinery and perhaps several kind of processes integrated in a 'plant' or by building a 'project'.

The project could be for petrochemical purposes offshore or onshore, water purification, distribution or cleaning, chemical processes, gas, steam or a large number of other things, and located anywhere in the world.

What would then decide the piping specification and valve specification, and how independent are the one of the other?

Again from the top down:

a) Any local rules or special rules related to the location and process. General area (US, BS, EN, JIS etc), auditing companys (UL, DNV, etc.. ) process locally (radiation, emission, explosive, sour service etc). Will apply to the whole project.

b) Any specific demands set down by the end user. will apply to the whole project.

c ) 'Normal best practice' related to the process and point a).. (how we usually do things here...), but also commercially related to best/cheapest available comercially at the given location. Will apply to the whole project.

d) The valves and the piping must obviously fit together and are as such not unindepent of each other. The valve specification should however not be decided by the piping engineer alone, but be cross-corelated to the overall project specifications as indicated above.

e) At an early project description stage it would always be wise to 'open up' for alternative bidding for any mechanical device, as long as point a) and b) are satisfied.

I do not know if theese roundabout comments will help you. Correlation between piping and valve specification are newly discussed, try to search all forums.

Good luck!

 

[gerhardl]

Lena1183,

Here is the thread I thought about, might be of interest for you.

thread408-253834

 

[Lena1183]

Tks rneill & gerhardl.

Gerhardl, i have already seen that link (thread 408..) before posting my query, but i hope these two are different.