Can GPH Be Converted to PSI for Leak Testing?

In summary, the conversation is about converting gph to psi for a pressure test on a 24" pipe. The pipe lost 4 psi during the test, and the person is looking for help to convert the loss to gph. However, since the pipe was plugged on both ends, there was no flow, and the person questions the relationship between pressure and flow.
  • #1
CaityAnn
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How do I convert gph to psi?...

Here is the deal, we are testing a 24" pipe for leaks doing a pressure test. the pressure at the pipe in question is 185 psi, and it lost 4 psi. I have a chart showing the allowable loss in GPH, but I don't know how to convert to PSI. Since this was a test, the pipe was plugged on both ends, therefore there was no flow.

Any help appreciated...
 
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  • #2


How long did it take to lose 4psi?
 
  • #3


You also need the pipe volume.
 
  • #4


CaityAnn said:
...the pressure at the pipe in question is 185 psi...the pipe was plugged on both ends, therefore there was no flow.

That should answer your question. You can have pressure without flow, so how can they be related?
 
  • #5


Converting from gallons per hour (gph) to pounds per square inch (psi) requires knowledge of the specific gravity of the liquid being tested. Once the specific gravity is known, the conversion can be done using the following formula:

psi = (gph x 8.33) / (specific gravity x 60)

In this case, since the pipe was plugged and there was no flow, the specific gravity can be assumed to be 1 (the specific gravity of water). Using this information and the given values, the conversion would be:

psi = (4 x 8.33) / (1 x 60) = 0.555 psi

Therefore, the allowable loss in psi would be 0.555 psi for this test. It is important to note that this is a general conversion and may not be accurate for all liquids. If you are testing a different liquid with a different specific gravity, the conversion may be different. It is always best to consult a conversion chart specific to the liquid being tested for more accurate results.
 

FAQ: Can GPH Be Converted to PSI for Leak Testing?

1. What is the formula for converting gph to psi?

The formula for converting gallons per hour (gph) to pounds per square inch (psi) is: psi = (gph x 8.34) / (60 x A), where A is the area of the pipe or container in square inches.

2. Can I use this formula for any type of liquid?

Yes, this formula can be used for any type of liquid as long as the units for gph and psi are consistent. For example, if gph is in US gallons and psi is in US pounds per square inch, the formula will work for liquids such as water, oil, or gasoline.

3. How do I determine the area (A) of the pipe or container?

The area (A) can be calculated by multiplying the diameter of the pipe (in inches) by itself and then multiplying by 0.7854. If the container is not a perfect circle, you can use the formula for the area of the shape (e.g. rectangle, triangle) that most closely resembles it.

4. Is there a conversion factor for gph to psi?

No, there is no specific conversion factor for gph to psi as it depends on the size of the pipe or container. The formula takes into account the area of the pipe or container to accurately convert the flow rate (gph) to pressure (psi).

5. Why would I need to convert gph to psi?

Converting between gph and psi is useful for understanding the relationship between flow rate and pressure in a liquid system. This information is important for designing and maintaining systems such as pumps, filters, and irrigation systems.

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