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What do emergency pressure relief systems do?

Posted on October 21st, 2021

Emergency pressure relief systems help protect storage tanks, vessels, containers, silos and processing plant equipment from excessive pressure.

Overpressure can be caused by a number of factors, including external fires, abnormal processes, equipment failure or changes in ambient conditions. External fires are particularly dangerous because they lead to significant temperature changes and rapid pressure shifts.

Standard pressure and vacuum relief valves can be used to protect against normal pressure changes. But these systems aren’t designed to cope with fires.

open vent pressure relief valves

Fires can lead to loss of containment and catastrophic explosions, resulting in damage, financial losses and the potential for human casualties or fatalities.

Features and benefits of emergency relief systems:

  • High flow capacity for improved venting
  • Low leakage
  • Available in a range of sizes
  • Fully tested and certified
  • Self-draining
  • Non-sparking design
  • Can provide access to tanks/vessels

Emergency relief materials

Emergency relief systems can be manufactured using a range of materials.

System body parts are generally made from materials including aluminum, carbon steel and stainless steel. Stainless steel is also used for the body trim, while PTFE is used for the valve diaphragm.

In hazardous environments, non-standard materials such as Hastelloy and various plastics can be used. We can also use special coatings in extreme environments, including PTFE for low-temperature internal components.

Emergency relief sizing

Emergency pressure release systems need to be sized accurately for their safe operation. System sizing is determined by the physical properties of the reaction components.

Emergency relief maintenance

Emergency relief systems are generally easy to maintain. Our systems use standard components that are easily interchangeable and replaceable.

A lightweight design means that equipment is also easy to handle.

Emergency relief connections

All valves are supplied with drilled flanges to meet individual requirements.

B400 Emergency Relief Manway

In addition to protecting tanks and vessels from external fires, the B400 Emergency Relief Manway also allows access to the tank for inspection and/or cleaning purposes.

This product can be manufactured in a range of sizes, using corrosion-free materials including carbon steel, stainless steel and aluminum.

b400 emergency relief manway diagram

B400 PV Emergency Relief Manway with Vacuum Relief

Like the standard B400 emergency relief system, the B400 PV unit has a manway for tank inspection or cleaning.

This unit has a spring loaded vacuum relief system with standard vacuum settings of between -2 mbarg and 50 mbarg.

B800 Overflow Valve

Easy to maintain with standardised parts, the B800 also self drains.

B800 overflow valve diagram

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