When Selecting Hydro‐testing as a means of proof testing that a system can withstand thpressure of operations it is important to understand what is applicable to the job. A hydrostatic test is a way in which pressure vessels such as pipelines, plumbing, gas cylinders, boilers and fuel tanks can be tested for strength and leaks.
Water Quality‐ when hydro‐testing stainless materials it is important that the water quality is low in chlorine content. Cl2 (chlorine) is a very potent oxidizer (reason it kills bacteria) and therefore high levels of Chlorine may accelerate chloride corrosion of stainless steels. 304 and 304L, 321 SS may be used for “water applications” with up to 2 ppm chlorine, while 316 and 316L alloys may “take” up to 4 ppm. During hydro‐testing it is important to confirm with the
water supplier in the area that the chlorine levels are within tolerance, this can be especially problematic during spring as there is high levels of runoff in the rivers.
When recording hydro‐tests clients may require both chart recording, pictures, as well as digital recording devices be made available.
Hydro‐Test Chart Recorder Paper are used to show the needle marks on the recorder to prove that the test was held for a designated time as well as pressure.
Digital recording devices are very useful for companies to provide charted tests that allow the client to review the test results and ensure that the time and pressure was achieved during the test.