A valve is a mechanical Organe being used for closing and opening a room or a conduit with the request.

Mechanics

The valves are essential to the operation of some Moteur S. They are generally actuated by a Camshaft S with one or more individual return springs, or by bar of torsion (Honda CB 450). They are said to mechanically operated valve. In the case of some internal combustion engine, it are simply ordered by the difference in pressure between their two faces (automatic valves).

Safety

A relief valve (also known as valve of safety) is a device safety against overpressures in units subjected to Pression.

One installs a valve of Sécurité (called Spill valve on the vehicles with Turbocompresseur) on the tanks/pipings of Gaz/Liquide which can be subjected to variations of Pression, like on steam boilers

For example, a valve allows the exit of the vapor when the pressure reaches a certain threshold in a Autocuiseur. A small ball closed by a spring acts as relief valve if the revolving valve (that which whistles) would be blocked. The spring is damaged so as to release the opening of the ball to a certain value of acceptable Pression by the pressure-cooker.

The tanks of LPG of the cars comprise a valve of safety, in order to avoid an explosion of the tank in the event of fire (fire external generating the rise in pressure of LPG in its tank)

In industry, the devices safety against overpressures generally answer standards, laws or directives. The principal ones are:

  • ASME (American Society off Mechanical Engineers) Boiler & Presses Vessel Code, Section VIII, Division 1

    • API
  • (American Petroleum Institute) Recommended Practice 520 and API Standard 526 (pressure > 1 barg), API Standard 2000 (depression and low pressure > 1 barg)
  • ISO (International Organization Standards) 4126
  • IN 764-7 published by CEN (European Committee for Standardization)
  • AD-Merkblatt (in Germany)
  • DESP 97/23/CE (Directive of the Equipment under Pressure) (in English the DEVELOPING COUNTRIES 97/23/EC)

List partial manufacturers of relief valves (pressure > 1 bar) in the world: --November 29th, 2007 with 05:50 (THIS)

  • Sarasin-RSBD (France)

  • Sapag (France)
  • H+ Valves (France)
  • Crosby (the USA)
  • Consolidated (the USA)
  • Anderson-Greenwood (the USA)
  • Farris (Canada)
  • Fukui (Japan)
  • Toa (Japan)
  • To injure (Germany)
  • Bopp & Reuter (Germany)
  • Sempell (Germany)
  • Broady (England)
  • Triangle (England)
  • Tai (Italy)
  • Ast (Italy)
  • Carraro (Italy)
  • Parcol (Italy)
  • Besa (Italy)

List partial manufacturers of relief valves of depression and low pressure (pressure < 1 bar) in the world: --November 29th, 2007 with 05:50 (THIS)

  • Sarasin-RSBD (France)
  • 3B Controls (England)
  • Marvac (England)
  • Whessoe-Varec (the USA)
  • Protectoseal (the USA)
  • Rampini (Italy)

Language

In general in the French language, the term “valve” indicates a loophole or a means cause a drop in the nervous tension ( Stress ).

See too

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