Testing of Flanged Components Along with the Pipeline

Steel type and temperature rating...

https://law.resource.org/pub/us/cfr/ibr/004/mss.sp-44.1996.pdf

The Engineer/Surveyor for the insurance company responsible for providing burst insurance cover certainly will.

Pick up the phone and talk directly to that individual. It is so much faster than waiting for responses here.

I dont know the answer but I am concerned you are mixing some terms

The test pressure is 1.5 times the design pressure.

Except when it isn't. I think the new standard is 1.3 times but it dependent on the design temperature of the piping.

Flanges have rated pressures which are nominally 150#, 300# etc but the actual design and test pressures of them are not those pressures and also vary with temperature eg 150# Carbon Steel is rated for 19.6barg at ambient (10C) temperature.

So you could have a 150# system with a 10barg design pressure.

Test Pressure = 13barg

Rated Pressure = 19.6 barg

but note although a 150# flange should be good for 19.6barg unless its been hydrotested you cannot be sure.

BUT I am not a piping engineer this is bits and pieces I have picked up as a process engineer

Ask an expert

This is just bureaucrazy at its finest; whoever said that various "Codes" have to be compatible? Not even God was smart enough to address that.

As it is not possible to test the pipeline without testing its flanged components, and vice-versa, please explain how this query has arisen?

Please explain the outcome of the telephone call to the Engineer/Surveyor for the insurance company for the further enlightenment of the reader?

simonsd - In my opinion the product temperature does not affect the hydro testing of the components since when testing with water at ambient temperatures this does not play a role. Also my question was on the maximum pressure limit to which the falnges/flanged components can be tested to.

I am using B31.3 from 2004, i will certainly look at the newer edition.

PWSlack- This query was raised during the testing of facility piping which included flanges and flanged components, test pressure exceeded the 1.5 times the rating of the flanges/fanged components which is a red flag here, i want to make sure this does not happen again or make changes so this wont be a red flag in the future even if we exceed the 1.5 X rating to next higher bar.

still working on this..

<...query was raised during the testing of facility piping which included flanges and flanged components, test pressure exceeded the 1.5 times the rating of the flanges/fanged components which is a red flag here.....this does not happen again or make changes so this wont be a red flag in the future even if .... exceed the 1.5 X rating to next higher bar....>

The solution was indicated in #2 above. Please explain why that avenue has not been explored to exhaustion?

Fanged components? Now, I've heard of water piping before, but not water moccasin piping!

That's what's called a plumbing snake!

Hi Anon

Sadly your opinion is not the one that will be considered in a court of law (and nor is mine)

Product temperature is not a term that I used and I do not know hat you mean by the term.

I am a process engineer and my role in these circumstances is to specify the design conditions for the piping based on its operating conditions and suitable design margins (based on experience, service, customer requirements etc)

A piping engineer will then use codes to determine the test pressure for the pipe.

The design temperature for the piping IS a key attribute in calculating this test pressure. Hydro-testing is carried out at ambient temperature and so a suitable pressure has to be calculated to allow for a test margin and for the fact that at higher operating / design temperatures metals are weaker.

For example the limits of 150# piping are

38C, 19.4barg; 94C, 17.7barg, 150C, 15.6 barg for Carbon Steel piping.

So if the design temp for the pipe is below 38C you do not apply a correction.

However if piping is required at 19.4 barg at 90C, then firstly it exceeds the limits of 150# piping and so will need to be 300# piping and then to generate a test pressure for ambient temperature I would apply the (roughly 10%) factor between the limits (19.4/17.7) and then apply the 1.3 to the result

ie roughly speaking correcting 19.4barg at 90C to ambient gives a design pressure of 21.3barg and thus a test pressure of 27.6barg.

However as noted above this is not my field of expertise this is just my practical handle on matters and I may have used the wrong factors but the general sense

If you are using standards over 10 yrs old then there is a problem.

Your original question mixed the use of test and rated pressure and from your response I am not sure if you understand the difference. If english is not your first language then your english is much better than my french, german or korean, but you need to get help in seeing the distinction.

In my experience there are three pressures relevant to piping / flanges

Design Pressure - this is calculated on a case by case basis and is a margin above the maximum operating pressure which the pressure in the piping will not exceed.

Test Pressure - calculated from the design pressure (and including a factor based on temperature) for each component or circuit. This is the pressure to which the piping and components will be subjected to prove that it can withstand the design conditions.

Rated Pressure - to simplify piping design flanges are specified in discrete pressure ratings. These can be thought of as the maximum combination of design pressure / design temperature to which a flange can be subjected.

The Rated Pressure will always be higher or equal to the design pressure.

Going back to your original post

Piping and components in a 10barg Design pressure 94C design temperature system would be rated at 150#

Design Pressure = 10barg

Test Pressure = 1.3 * (19.4/17.7) * 10 = 14.3 barg

The Maximum possible test pressure for a 150# system is 1.3 * 19.4 = 25.2 barg

As the design pressure is normally less than rated pressure it is possible to have

Test Pressure >= 1.3 * design pressure and

Test Pressure = 1.3 * rated pressure

Didn't notice the typo.

Can you explain what #2 meant above?

This piping is intended for hydrocarbon service, i have to verify if the integrity of the flange is compromised.

Then do a hydraulic test, Mildred! Good grief.