Hydrostatic Test: Calculate Leakage Rate of Thread & Coupling

[Northdust]

I am looking to conduct a hydrostatic test on two short pieces of pipe connected via coupling a round thread coupling. Our intent is to pressurize the sample to 6000 kPa and hold for 1 hour to see if there is any sort of pressure drop, and if so what is the leakage rate of the system through the thread and coupled connection.

With this set-up we will know (or approximately know) the volume of the sample, the density of the test fluid, both initial and final pressure, both initial and final temperature (hopefully constant), and time the sample was pressurized.

If there is a drop in pressure over this time frame could someone help me determine the quantity of the test fluid that has leaked from the test specimen.

Regards,
Northdust

 

[FredGarvin]

If the fluid is a gas and can be treated as ideal, just use Boyle's Law with the total test duration to get the volumetric flow of the leak.

 

[Northdust]

The test fluid will be water.

 

[Doug Huffman]

Collect the leakage or measure the volume injected to maintain pressure.

 

[FredGarvin]

The true way to do it is to put a flow meter in line with the pressure producing part, i.e. pump. If the seals hold, there will be no flow. If there is a leak, the flow meter will tell you the rate. You can put a totalizer counter on the flow meter to give you the total amount flowed.

 

[stewartcs]

I am looking to conduct a hydrostatic test on two short pieces of pipe connected via coupling a round thread coupling. Our intent is to pressurize the sample to 6000 kPa and hold for 1 hour to see if there is any sort of pressure drop, and if so what is the leakage rate of the system through the thread and coupled connection.

With this set-up we will know (or approximately know) the volume of the sample, the density of the test fluid, both initial and final pressure, both initial and final temperature (hopefully constant), and time the sample was pressurized.

If there is a drop in pressure over this time frame could someone help me determine the quantity of the test fluid that has leaked from the test specimen.

Regards,
Northdust

Use the bulk modulus of water:

http://hyperphysics.phy-astr.gsu.edu/HBASE/permot3.html

CS