BLAISE PASCAL in mid of the 17th century explained the phenomenon of pressure acting in all directions when confined in enclosed spaces like pipelines, equipment etc. He foresaw the extreme usefulness of accurate measurement of pressure and scientists all over the world are indebted to PASCAL for his pioneering work on the subject. Accordingly, The International Body of Scientists has immortalized him by naming the basic unit of pressure as “PASCAL”.

Thus, we see that pressure is one of the prime process variables in most of the industrial sectors. Any unpredictable process upset can cause a sudden and alarming increase in pressure, more than the design or Maximum Allowable Working Pressure (MAWP) limits. This could result in the perilous rupture of pipelines and vessels leading to loss of both production and human life with irreparable damage to environment too, in other words……. PRESSURE is a savage force WHEN UNTAMED.

Boilers and Pressure Vessels play a critical role in almost every sector of the industry and Pressure Relieving Devices occupy a distinctive part in saving them from catastrophic disaster due to overpressure.

The primary purpose of a Pressure Relief device is the protection of life and property by releasing excess fluid in vessels, lines or system in abnormal or emergency situations and thus maintaining allowable limits of pressure at all time.

A Pressure Relief Valve must be properly sized, selected, tested and installed, in order to ensure its reliability thereby avoiding a possible catastrophic failure. It is vital that the Pressure Relief Valve that adheres to safety first is capable of working instantly, at all times, especially when all other system controls are rendered non-functional.

The sole source of power for any Pressure Relief Valve is its own process fluid, and its dependability is directly related to the complexity of the device. Thus, all efforts and time spent in sizing and engineering the system to provide adequate protection will be ineffective unless, maintenance, using established procedures and realistic inspection frequencies, is carried out at regular and required intervals. The importance of periodic maintenance should neither be underestimated nor underplayed, otherwise the Pressure Relief Valve would then function as a mere pressure controller for which it was not designed or selected.