Hydrostatic Test

<...How many pressure gauges to be used when a set of >20 coils are tested at a time?...>

The Engineer/Surveyor for the firm providing burst insurance indemnity cover reports for the equiipment will determine this.

<...What is ideal location to connect pressure gauge / gauges?...>

At the top. It's also a useful place to let the air out when screwing the gauge on.

<...If two gauges are connected (One at inlet /Bottom and other is at outlet / Top ) then do we expect a pressure reading difference in these two gauges?....>

Yes, there will be a pressure difference.

<... If yes then...How much difference?....>

Δp=ρgΔh

where p is pressure, ρ is the density of the fluid, g the acceleration due to gravity and Δh the difference in elevation between the two gauges.

<...Which gauge should show higher?...>

The lower one.

<...What are the other parameters to confirm?...>

The temperature at which the test was carried out should be on the Engineer/Surveyor's witness test report from the firm supplying burst indemnity insurance cover for the equipment. The report needs to be either

• placed in the General Register for the facility if the equipment is used internally, or
• a copy needs to be supplied to the end Customer with the equipment and the original archived.

I tried to use above formula to calculate pressure difference. I have tested a boiler coil with two gauges ( One at inlet - Bottom one and other at outlet - top one ) My test pressure was :- 200Kg / cm2 My coil tube size is Ø38.1 x 4.05 thk testing media is water at ambient temp (30deg C) dial gauge range is 0 - 420 Kg / cm2 I considered values as follows Delta P :- to be calculated Density of water is 1gm/cm3 gravitational acceleration is 9.8m/sec2 height difference between two gauges - 2Meter Using formula I got the answer as 0.001x980x200 = 196 kg/cm2 I am not getting convinced with this answer What I want to find out is how much pressure readings difference I am suppose to get in top and bottom gauges when test conducted with parameters s explained above regards deorem