Pipe Line Hydro Static Pressure Test

[djmret]

We reciently completed a hydro (14000 kpa) on a 24" line. As the temperature fell the pressure raised slightly approximately 200 kpa.
What is the relationship between pressure and temperature,is there a caculation or graph for making this correction.

 

[dtn6770]

I would have expected the pressure to drop with a reduction in temperature. What was the temperature swing? I haven't tried the math but in theory the lower temperature may have increased the water's density and over some elevation differance prompted the pressure increase.

A less than 1.5% pressure dip should be viewed as fairly insignigicant, 14,000 kpa is a health hydro. How was the pressure measured? I'd question the low end resolution of a gauge that goes to 14,000 kpa.

 

[djmret]

Test pressure at start 14700 kpa, @ -6C
Test pressure at end of 4 hour hold 15120 kpa @ -5.5C
Pressure was measured with strip records at the low and high end of the lines.

 

[dcasto]

AWWW, brine!?

 

[BigInch]

Water expands with decreasing temperature when the temp is below about 2ºC!

BigInch-born in the trenches.

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