Hydrostatic Pressure Testing Vs Pneumatic Pressure Testing

Playing an enormous role in just about every manufacturing plant today, pipelines are much more than just about placing a couple of pipes and tubes together, and expecting them to perform. Used in extremely harsh and demanding conditions, pipelines can not only cause extensive damage and financial loss, but they can also cause fatalities if not installed, operated and serviced periodically.

Whether you’re working with liquid chemicals or gas, in order to certify that pipelines, plumbing, gas cylinders, boilers and fuel tanks can handle the load, Integrity Management regulations require manufacturers to consistently conduct integrity assessments by way of pressure testing. A non-destructive reliable method of determining the integrity of the pressure shell on equipment, pressure testing analyses ensure safety, reliability of operation and quality of piping, as well as rupture or leak integrity. Essential for new pressure systems, existing pressure systems, or installed pressure systems that have just undergone an alteration or repair – two practices are always used: pneumatic pressure testing and hydrostatic pressure testing. Below we take a closer look at each.

Hydrostatic Pressure Testing is a Commonly Accepted Safe Practice

A practice that involves filling the pipe system with red or fluorescent dyed water to aid in visual leak detection and pressurisation of the vessel, hydrostatic pressure testing is a commonly accepted safe practice that can be used in any manufacturing site by skilled operators. A practice that uses non-flammable and nontoxic gas, air or nitrogen to test the pressure system, pneumatic testing is much more dangerous and is only recommended for low application uses.

Pneumatic Testing is Limited to Lower Pressures or Smaller Systems

While hydrostatic pressure testing is hugely popular for the post-construction testing of hazardous liquid pipelines and higher stress natural gas pipelines, pneumatic pressure testing is rarely used for systems that operate at pressures above 100psig due to safety concerns. Limited to lower pressures or smaller systems, pneumatic testing is much more dangerous because of the higher level of potential energy stored during compression of the gas, which increases the chances of equipment failure and explosions.

Extremely low risk in terms of failure when compared to pneumatic testing, the only real disadvantage of hydrostatic pressure testing is the introduction of water in systems that must be water free. Following an approved test plan documented in a test record, it’s imperative that both types of pressure testing always be performed under strict conditions, ideally in a specially designated area with minimal personnel in the area.

For more information on hydrostatic pressure testing, as well any customised designs you may require for your precise operational needs, contact us at Bestline Manufacturing in Johannesburg.