Hydro is the universal short form for hydrostatic test, and it works as a verb: hydro the spool, it's been hydroed. Process piping is typically tested at about 1.5 times design pressure, held long enough for a full walkdown of every joint. Valves get their own shop shell test, and relief valves, control valves and instruments in the system are removed, gagged or blinded first.
Hydro on the new header is at 9, everything has to be filled and vented by then, and pull the PSVs.
Also heard as
- hydrostatic test
- hydrotest
- hydroed
Related terms
Shell test
A hydrostatic pressure test of the valve body and bonnet, run with the valve partly open, to prove the shell holds.
Golden weld
The final tie-in weld between new and existing piping that cannot be included in the hydrotest.
Gag
A clamp or screw fitted to a safety valve to hold its disc shut during a system pressure test.
Bleeder
A small vent or drain valve used to release pressure or fluid, especially between two block valves.