cooling water piping system

[2007eng]

Hi guys,
I'm carrying out a pressure test for 600 ton cooling water steel piping system.
I need to know the effect of temperature drop on the system pressure during the test.
On the copper piping system the relation is 0.1 bar for each 1 degree C, what about the water piping systems.
Thanks

[Brian_UK]

Are you conducting an "dry pressure" test or a "wet pressure" test of the water piping system?

[Sridhar1312]

Effect of temperature on pressure testing will depend on the quality of water used as I had an experience while pressure testing of cooling water pipe 10 Kg/cm2 and would increase to 14 Kg/cm2 and the authorities started questioning why you have increased the pressure.
When we told the pressure has increased on its own, we were asked to investigate and on getting the water analysis it was observed the water used had lot of dissoled gases which was the cause for increasing pressure.

[nike123]

Effect of temperature on pressure testing will depend on the quality of water used as I had an experience while pressure testing of cooling water pipe 10 Kg/cm2 and would increase to 14 Kg/cm2 and the authorities started questioning why you have increased the pressure.
When we told the pressure has increased on its own, we were asked to investigate and on getting the water analysis it was observed the water used had lot of dissoled gases which was the cause for increasing pressure.

Doesn't pressure rise/fall also because of change in water temperature (water expand 0,00023% for 1°F temperature rise), or temperature in both measurements are been the same?