Fire safe test apparatus

[hotbat]

Dear Every engineers

We have a fire safe test facility and will fire safe test according to API 607_5th two weeks from now.
but, we have any problem for apparatus such as upstream pipework.
API 607_5th mention that "The test equipment shall be designed so that if the nominal diameter of the pipewok situated immediately upstream of the test valve is larger than DN25 or one-half the DN of the test valve"
But, Inspector of the third party asserted that upstream pipe size of Large sized valves must employed to one-half the DN of the test valve.
Unfortunately, our facility fixed to DN25 already
and we don't have any times in order to modification
pls, advice for right interpretation to above problem

 

[unclesyd]

In your post you state that the upstream pipe has to be 1/2 DN of the test valve with a minimum size of DN25. You evidently have fixed you upstream pipe at DN25, which will take care of any size up to DN50 without a change in up stream pipe size.
I personally see no way around this requirement.

In two weeks you can build a lot of pipe spools>

 

[hotbat]

Dear unclesyd!

Thank you for your early reply

But, this is sad news, if we must be size up from DN25 to 1/2DN of the test valves to upstream pipe work...

I recieved any technical papers from SWRi(South West Research Institute). pls, find attached file and see Figure 1, (B)

Shall I refer to this guide?

 

[gerhardl]

I am no expert but please observe:

The papers you have received has explicit noted that the paper itself is an abbreviation and summary of some main points, and is no replacement for the specification in the standard.

As I read the summary it also describes the pipesize required to be minimum half nominal diameter, and in any case for small valves no less than etc...

The reason for this is obvious, the firesafe test is set up on certain specification to simulate in best possible way a 'real' situation. As in any standard there is no way around a specification requirement.

If you look around this site you will find a number of questions where engineers have met practical problems regarding ability to follow standards.

Trying to find a cheap, fast and simple solution all types of arguments and suggestions come up. But again: sorry! there is no easy way around, standards must be followed, and in theese cases redesign is the only possible way out.