Hydro-Test (Hydrostatic Testing) : To apply hydraulic pressure (usually with water) in order to find leaks in tubing, lines, piping, vessels and equipment. (ITOGP)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}