Safety valve:

An automatic valve that opens or closes when an abnormal condition occurs (e.g., a pressure relief valve on a separator that opens if the pressure exceeds the set point, or the shutdown valve at the wellhead that closes if the line pressure becomes too high or too low).

2.

A valve installed at the top of the drill stem to prevent flow out of the drill pipe if a kick occurs during tripping operations.

Terms Related to Safety valve

• Pressure relief valve

  A valve that opens at a preset pressure to relieve excessive pressures within a vessel or line. Also called a relief valve, safety valve, or ...

• Drill stem safety valve

  A special valve installed below the kelly. Usually, the valve is open so that drilling fluid can flow out of the kelly and down the ...

• Valve

  A device used to control the rate of flow in a line to open or shut off a line completely, or to serve as an ...

• Check valve

  A valve that permits flow in one direction only. If the gas or liquid starts to reverse, the valve automatically closes, preventing reverse movement. Commonly ...

• Nail pin

  A pin shaped like a carpenter's nail and placed in a pressure relief valve. When the pin shears, it opens the valve to relieve pressure ...

• Downhole safety valve

  A downhole device that isolates wellbore pressure and fluids in the event of an emergency or catastrophic failure of surface equipment. The control systems associated with ...

• Stabbing valve

  A special drill stem valve that, when in open position, allows fluid to flow through it, thus allowing the valve to be stabbed into the ...