Inspectioneering
Explore:

Pressure Relieving Devices (PRDs)

Overview of Pressure Relieving Devices (PRDs)

Pressure Relieving Devices (PRDs) are components used in refineries, chemical plants, and other similar facilities to prevent pressure vessels and other equipment from overpressurization by relieving excess pressure when necessary. They can be used release gas, steam, liquids, or vapors. Properly functioning pressure relief devices are essential for protecting plant personnel and equipment, since unexpected overpressure events can potentially cause equipment damage, loss of containment, and result in costly plant shutdowns.

Pressure relieving devices include mechanisms such as Pressure Safety Valves (PSV) and Pressure Relief Valves (PRV), although there are other types of pressure relieving devices as well, such as Rupture Disk Devices and Pin-Actuated Devices. These devices can come in many different sizes and shapes and allow pressurized fluids or gasses to escape through a secondary passage out of the system so that pressure cannot build up beyond safe operating limits.

Most pressure relieving devices work automatically, opening once certain internal pressure limits are reached or exceeded, and closing once the pressure has returned to an acceptable level. The level of pressure at which a valve will re-seal is known as its blowdown. Blowdown levels usually vary from around 2-20% and some valves have adjustable blowdowns.

In the United States and many other countries, industries are required to use PRDs on pressure vessels, piping, and other equipment. Several codes and standards that discuss the safe construction and operation of PRDs include API RP 520, API RP 521, API RP 526, API RP 527, API RP 576, ASME PD 583 and ISO 4126-1:2013. 

 

Is this definition incomplete? You can help by contributing to it.

Share this Topic

Related Topics

Aboveground Storage Tanks (ASTs) Boiler Tubes Boilers Bolts Bull Plugs Coker Units Cooling Towers Crude Distillation Unit (CDU) Deaerators Fin Fan Coolers Fired Heaters Fixed Equipment Flanges Flare Systems Furnace Tubes Glass-lined Equipment Heat Exchangers HF Alkylation Units Hydrocracking Unit Hydrotreater Pipelines Piping Pressure Vessels Rotating Equipment Turbines Valves
Articles about Pressure Relieving Devices (PRDs)
    Companies
    Videos related to Pressure Relieving Devices (PRDs)
      White Papers related to Pressure Relieving Devices (PRDs)
        Downloads & Resources related to Pressure Relieving Devices (PRDs)
          Events related to Pressure Relieving Devices (PRDs)
            News related to Pressure Relieving Devices (PRDs)
              Stay up-to-date with the latest in industry — for free. Join thousands
              of others

              Inspectioneering Journal

              Explore over 20 years of articles written by our team of subject matter experts.

              Company Directory

              Find relevant products, services, and technologies.

              Job Postings

              Discover job opportunities that match your skillset.

              Case Studies

              Learn from the experience of others in the industry.

              Event Calendar

              Find upcoming conferences, training sessions, online events, and more.

              Industry News

              Stay up-to-date with the latest inspection and asset integrity management news.

              Blog

              Read short articles and insights authored by industry experts.

              Acronyms

              Commonly used asset integrity management and inspection acronyms.

              Asset Intelligence Reports

              Download brief primers on various asset integrity management topics.

              Videos

              Watch educational and informative videos directly related to your profession.

              Expert Interviews

              Inspectioneering's archive of interviews with industry subject matter experts.