Hydro
Hydro turns up in 2 fields: valves, hydrography. Here is what it means to the people in each one.
Hydro in valves
A hydrostatic pressure test: filling a valve, piping system or vessel with water and pressurizing it to prove strength.
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."
Hydro in hydrography
Clipped insider word for hydrography, hydrographic surveying, or the survey team itself.
Shorthand for the discipline, the activity and the people. Crews say they are doing hydro, ship's officers talk about the hydro department, and a hydro day is a day spent running lines rather than transiting or fixing gear. On mixed marine projects the word separates the depth survey team from geophysics, geotechnical or construction survey crews.
"We lost two hydro days to the swell, so the patch test slides to Friday."