Search results
Results From The WOW.Com Content Network
A blowdown valve (BDV) is a type of shutdown valve designed to depressurize a pressure vessel by directing vapour to a flare, vent or blowdown stack in an emergency. BDVs fail-safe to the open position upon failure of the control system. [1] The type of valve, type of actuation and performance measurement are similar to an ESD valve.
If there is a spring inside of the actuator, it will force the valve open or closed and will keep it in that position while power is restored. An actuator may be specified "fail open" or "fail close" to describe its behavior. In the case of an electric actuator, losing power will keep the valve stationary unless there is a backup power supply.
CITHP – closed-in tubing head pressure (tubing head pressure when the well is shut in) CIV – chemical injection valve CK – choke (a restriction in a flowline or a system, usually referring to a production choke during a test or the choke in the well control system)
ISO 14617 Graphical symbols for diagrams is a library of graphical symbols for diagrams used in technical applications. [1] ISO 14617 consists of the following parts: Part 1: General information and indexes; Part 2: Symbols having general application; Part 3: Connections and related devices; Part 4: Actuators and related devices
A control valve is a valve used to control fluid flow by varying the size of the flow passage as directed by a signal from a controller. [1] This enables the direct control of flow rate and the consequential control of process quantities such as pressure, temperature, and liquid level.
In conventional PRVs, the valve is normally held closed by a spring or similar mechanism that presses a disk or piston on a seat, which is forced open if the pressure is greater than the mechanical value of the spring. In the PORV, the valve is held shut by piping a small amount of the fluid to the rear of the sealing disk, with the pressure ...
ISO 7010 states on all symbols with a first aid cross, that it "may be replaced with another element appropriate to cultural requirements". In countries with a Muslim -majority population, an appropriate symbol is the crescent .
A safety valve is a valve that acts as a fail-safe. An example of safety valve is a pressure relief valve (PRV), which automatically releases a substance from a boiler, pressure vessel, or other system, when the pressure or temperature exceeds preset limits. Pilot-operated relief valves are a specialized type of pressure safety valve.