Propylene Glycol Hydro Testing

Posted by novamen on October 4th, 2017

Hydro testing is conducted to determine the integrity of pipelines, gas cylinders, plumbing, fuel tanks, boilers, and other pressure vessels, to discover leaks and verify the strength. It is required before a new installation is put into service and after repairs and shutdowns are completed, to make sure the equipment can operate properly and safely according to the required specifications before they are returned to service. Propylene glycol is used in hydro testing where environmental sensitivity is required or where ethylene glycol may not be recommended. Adding propylene glycol is essential when testing during winter, as water will freeze and pipes and equipment may burst during freezing temperatures without it. Here are some test procedures for propylene glycol hydro testing: 

• Using the water jacket method – This method can be used to test small pressure vessels. This is accomplished by filling the vessel with fluid and loading it into a test jacket, which is a sealed chamber filled with water. The vessel is pressurized, allowing it to expand in the test jacket, which forces the water into the measuring tube, determining total expansion. The vessel is then depressurized, and as it shrinks back to its original size, the fluid should flow back to the jacket. 

In some cases, the vessel may not return to its original size, resulting in a phenomenon known as ‘permanent expansion’. A vessel may be decommissioned when its percentage of expansion is too high. 

• Hydrostatic pressure testing – The pipe is filled with liquid which can be plain water, or most commonly a water and glycol mixture. Dye is often added to help detect leaks. The vessel is pressurized and then observed to see if the pressure is maintained. Pressure loss indicates leaks in the system. Visually identifying leaks is easier when dye is added. The strength of the pipe can be determined by measuring permanent expansion deformation. 

Renting hydro testing fluid, rather than purchasing, is a common practice. It eliminates the need to buy, store and dispose of propylene glycol after use. Reputable providers carry different volumes for short, long-term, and medium-term rentals, and the service covers transportation to and from your test site. Tank rentals can be included upon request, and several kinds of hydro testing fluids, including propylene glycol, are available. 

About the Author: 

Novamen Inc. is a privately held company and was started in 2010. With over 30 years of combined knowledge and experience in these markets, the founders are building the company with the intention of offering products and services to industrial clients that go beyond those of traditional chemical companies. Operating in Alberta, Novamen’s focus is primarily to the industrial, oil, natural gas and mining industries throughout Canada. Visit Novamen Inc. to learn more about the chemical solutions you need that are more accessible, efficient, and cost effective than ever.