Overpressure Protection System Compared: PSV or HIPPS?

Related Vendors

DÜPERTHAL Sicherheitstechnik GmbH & Co. KG

Italvacuum, Srl

Donadon SDD Srl

While HIPPS has the mentioned advantages over PSV, it has certain disadvantages too:

• Since HIPPS acts by closing an inlet flow-stream, it may lead to shut-down and production losses. The plant has to be restarted, and hazardous events and associated risks are more likely during start-up and shut-down operations than normal operations.

• Whereas PSV can be useful for all the commonly known over-pressure scenarios, HIPPS cannot be applied for all such scenarios. For example, it cannot be applied for over-pressure scenarios such as fire and thermal expansion. Thus, HIPPS may not be used as a substitute of PSV in all situations, rather it can supplement the PSV.

• Stricter requirement of maintenance, testing and inspection may add to cost of HIPPS.

• In order to avoid spurious functioning of the sensor, two or three sensors may be required to increase the regularity with 1oo2 or 2oo3 voting, which may complicate the system and reduce the safety reliability of HIPPS.

While both PSV and HIPPS serve the purpose of providing protection against overpressure, they function entirely different. A PSV is a mechanical device whereas HIPPS is an instrumented system. The advantages and disadvantages of one over the other are underpinned by the fact that the PSV provides overpressure protection by releasing containments from the system into atmosphere (often after flaring) whereas HIPPS does the same by shutting the source of the overpressure. A decision as to which one to be applied in a given situation has to consider cost and benefits of the two as discussed in above paragraphs.

* * The author is General Manager and Head of Department-Process at Simon India. Contact: Phone +91-11-42602222

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