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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.
A depressurization system comprises an actuated valve and a restriction orifice. The BDV valve is normally held in the closed position but opens on demand or on failure of the actuator. A restriction orifice (RO) downstream of the BDV is sized to achieve the desired blowdown rate. A locked-open valve may be located downstream of the orifice.
A clean-in-place unit on display at the World of Coca-Cola in Atlanta. Clean-in-place (CIP) is an automated method of cleaning the interior surfaces of pipes, vessels, equipment, filters and associated fittings, without major disassembly. CIP is commonly used for equipment such as piping, tanks, and fillers.
Unlock and open, then close and relock the vent and drain valves. Unlock and open door, load pig into launcher, close and lock door. Unlock and open valves V1 and V3, to create a flow path through the launcher. Partly close ‘kicker’ valve V2 to launch the pig. The launch alarm XA will indicate when the pig has been launched. Open valve V2 ...
Fittings allow multiple pipes to be connected to cover longer distances, increase or decrease the size of the pipe or tube, or extend a network by branching, and make possible more complex systems than could be achieved with only individual pipes. Valves are specialized fittings that permit regulating the flow of fluid within a plumbing system.
"Air or control signal failure to open" – On failure of compressed air to actuator, the valve opens under spring pressure or by backup power. The modes of failure operation are requirements of the failure to safety process control specification of the plant. In the case of cooling water it may be to fail open, and the case of delivering a ...
Unlike a ball valve, the disc is always present within the flow, so it induces a pressure drop, even when open. A butterfly valve is from a family of valves called quarter-turn valves. In operation, the valve is fully open or closed when the disc is rotated a quarter turn. The "butterfly" is a metal disc mounted on a rod. When the valve is ...
Partial stroke testing (or PST) is a technique used in a control system to allow the user to test a percentage of the possible failure modes of a shut down valve without the need to physically close the valve. PST is used to assist in determining that the safety function will operate on demand.