Hydrostatic Test Check

Before a line goes into service it is filled with water and pressurised. For a support, this is a different load case from operation — often the heaviest one it will ever see — and the software checks it separately.

Why it is a separate case

Two things change during the test.

The line is full of water. A large-diameter vapour or gas line carries almost nothing in operation and a great deal of water during the test. The ratio between test and operating load can be several times over.

The pipe is cold. Materials are at full strength, so no temperature correction applies. But equally, thermal movement is zero and springs sit at their installed position.

The combination is a support at its cold position carrying its heaviest load.

What the software does with it

Enter the value in Hydrotest Load on the support datasheet. Then:

• It never selects a model. Selection uses the operating load.
• It is only compared against the capacity of the load-bearing parts.

If the comparison fails, the software warns. It does not change the selection.

Which components are checked

The check applies to the parts that carry the load in tension or compression.

What to do when it fails

In order of preference:

1. Check the value you entered. The hydrotest load should be the weight of the water-filled line at that support, not the test pressure and not a factored operating load.

2. Provide temporary support for the test. Common practice on lines where the test load is disproportionate to the operating load. A temporary support under the line during the test removes the case entirely. This is an engineering decision outside the software, but it is frequently the right one on large vapour lines.

3. Accept it with justification. If your project specification permits a lower factor of safety during a controlled, one-off test with no personnel present, that is a documented decision — not something to leave as an unread warning.

If you leave the field blank

The check is not performed. No warning is issued for its absence.

On any line that will be hydrotested, this means an unchecked load case. It is worth making the field part of your standard datasheet routine rather than something filled in when remembered.