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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.
BTO/C – break to open/close (valve torque) BTU – British thermal units; BTU – Board of Trade Unit (1 kWh) (historical) BU – bottom up; BUL – bottom-up lag; BUR – build-up rate; BVO – ball valve operator; bwd – barrels of water per day (often used in reference to oil production) bwipd – barrels of water injected per day
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.
λ D = The dangerous failure rate of the safety function. TI FC = The full closure interval, i.e. how often the valve must be full closed for testing. TI PST = The partial stroke test interval. The proof test coverage is a measure of how effective the partial stroke test is and the higher the PTC the greater the effect of the test.
A high-integrity pressure protection system (HIPPS) is a type of safety instrumented system (SIS) designed to prevent over-pressurization of a plant, such as a chemical plant or oil refinery. The HIPPS will shut off the source of the high pressure before the design pressure of the system is exceeded, thus preventing loss of containment through ...
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.
The blue valve body is visible in-line with the pipe. The valve actuator opens or closes the butterfly disc of the valve based on electrical signals sent to the actuator. Another valve actuator is visible in the background, with windows to indicate the valve position. A valve actuator is the mechanism for opening and closing a valve. Manually ...
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 ...