Pressure relief valve

Pressure relief valve

A pressure relief valve is a safety device that relieve in case of overpressure in vessel or piping. The generic term is or pressure relief Valve (PRV) or pressure safety valve (PSV).

Main types of pressure relief valves include:
*Relief valve (RV) automatic system that relief by static pressure on a liquid. It specifically open proportionally with pressure increasing.
*Safety valve (SV) automatic system that relieve static pressure on a gas. It specifically opens almost straight to full lift after a pop sound.
*Safety relief valve (SRV) automatic system that relief by static pressure on both gas and liquid.
*Pilote operated safety relief valve (POSRV) automatic system that relief by remote command from a pilote on which the static pressure (from equipment to protect) is connected.
*Low pressure safety valve (LPSV) automatic system that relief by static pressure on a gas. The pressure is small and near the atmospheric pressure.
*Vacuum pressure safety valve (VPSV) automatic system that relief by static pressure on a gas. The pressure is small, negative and near the atmospheric pressure.
*Low and vacuum pressure safety valve (LVPSV) automatic system that relief by static pressure on a gas. The pressure is small, negative or positive and near the atmospheric pressure.

RV, SV and SRV are spring operated (even said spring loaded). LPSV and VPSV are spring operated or weight loaded.

Legal and code requirements in industry

In most countries, industries are legally required to protect pressure vessels and other equipment by using relief valves. Also in most countries, equipment design codes such as those provided by the ASME, API and other organizations like ISO (ISO 4126) must be compliant with and those codes include design standards for relief valves. [ [http://www.onetb.com/asme_code_countries.htm List of countries accepting the ASME Boiler & Pressure Vessel Code] ] [ [http://www.techstreet.com/cgi-bin/detail?product_id=235758 API 5210-1, Sizing and Selection of Pressure-Relieving Devices] ]

The main standards, laws or directives are:
* ASME (American Society of Mechanical Engineers) Boiler & Pressure Vessel Code, Section VIII, Division 1
* API (American Petroleum Institute) Recommended Practice 520 - Sizing, Selection, and Installation of Pressure-Relieving Devices in Refineries: Part I - Sizing and Selection
* API Standard 521 - Pressure-relieving and Depressuring Systems
* API Standard 526
* API Standard 527
* ISO 4126
* ISO 23251 - Petroleum, petrochemical and natural gas industries - Pressure-relieving and depressuring systems
* AD Merckblatt
* [http://ec.europa.eu/enterprise/pressure_equipment/ped/index_en.html PED 97/23/EC] (Pressure Equipment Directive)

References


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • pressure relief valve — A one way valve designed to open at a specific pressure to prevent pressures in the system from exceeding certain limits. In an engine s lubrication system, a pressure relief valve opens to relieve excessive pressure that the oil pump might… …   Dictionary of automotive terms

  • pressure relief valve — apsauginis vožtuvas statusas T sritis automatika atitikmenys: angl. pressure relief valve; relief valve; safety valve vok. Überdruckventil, n; Entlastungsventil, n; Sicherheitsventil, n rus. предохранительный клапан, m pranc. clapet de décharge,… …   Automatikos terminų žodynas

  • pressure-relief valve — i. In pneumatic and oxygen systems, the valve that ensures that the pressure of air or oxygen entering the working system is reduced to the correct value. ii. A valve that returns the fluid to the reservoir or manifold if its pressure rises above …   Aviation dictionary

  • negative pressure relief valve — A relief valve in an aircraft pressurization system that prevents the pressure in the cabin from becoming lower than the ambient outside pressure. The cabin air pressure safety valve combines functions of over pressure relief valve, vacuum relief …   Aviation dictionary

  • high pressure relief valve — [1] A safety valve located in the discharge line (six cylinder compressors) or the compressor block (two cylinder compressors) [2] Located somewhere on the high side of the air conditioning system often next to the receiver drier this safety… …   Dictionary of automotive terms

  • Temperature/Pressure Relief Valve —   A component of a water heating system that opens at a designated temperature or pressure to prevent a possible tank, radiator, or delivery pipe rupture …   Energy terms

  • pressure regulating valve — [1] any valve which maintains pressure at or under a certain pressure; specifically the pressure relief valve of the oil pump. [2] In a continuous injection system, part of the fuel distributor, consisting basically of a spring loaded steel… …   Dictionary of automotive terms

  • Relief valve — The relief valve is a type of valve used to control or limit the pressure in a system or vessel which can build up by a process upset, instrument or equipment failure, or fire. The pressure is relieved by allowing the pressurised fluid to flow… …   Wikipedia

  • relief valve — [1] A valve in the air pump of an air injection system which dumps part of the air at high pump speeds to prevent pump damage. It may be combined with the air gulp valve. [2] Safety device on a sealed system. It opens to release fluids before… …   Dictionary of automotive terms

  • relief valve — A pressure control valve in any fluid system, which limits the pressure in the system by releasing it at a preset value. The pressure is not allowed to be built up above this preset figure. A typical oil pressure relief valve …   Aviation dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”