Hydrotesting & Pneumatic Test

Prior to the introduction of hydrocarbons, hydrostatic or pneumatic testing is typically employed to confirm the integrity of pipework and vessels. For LNG/LPG facilities the presence of the water or moisture poses a number of potential startup and operational concerns. Proper design and engineering of the overall program for hydrostatic testing and subsequent draining and dehydration of the system are critical to the safe startup and commissioning of the system. Process system and dehydration technique significantly reduces the potential risk and complications commonly associated with system startup.

The hydrostatic test method is the mandated and preferred method of pressure testing. Hydrostatic testing presents a much lower safe hazard. associated with the stored energy, compared to pneumatic testing. A hydrostatic test is performed by using water as the test medium, whereas a pneumatic test use air, nitrogen or any non-flammable and nontoxic gas. Pressure tests (both hydrostatic and pneumatic) must always be performed under controlled conditions, following and approved test plan and documented in a test record. A single approved test plan could be used for severalsimilar tests, but for each test a separate test record in required. Pneumatic test are potentially more dangerous than hydrostatic test because of the higher level of potential energy stored during compressing the gas. Care must be exercised to minimize the change of brittle failure during testing by initially assuring the system is suitable for pneumatic testing