What is double block and bleed valves?
What is double block and bleed valves?
A double block and bleed valve is like having three valves in one. This trunnion style ball valve from Val-Matic provides double block and bleed in a single valve. This style can isolate piping on both sides of the valve (uni-directionally) to vent/bleed the valve cavity between the seats.
What is a block and bleed needle valve?
Block and Bleed needle valves provide controlled flow to high-pressure hydraulic and pneumatic systems through both shut-off regulation and diversion. These needle valves deliver safe, reliable operation to 20,000 psi.
What is trunnion in ball valve?
A trunnion mounted valve means that the ball is con- strained by bearings and is only allowed to rotate, the majority of the hydraulic load is supported by the Sy- stem constraints, resulting in low bearing pressure and no shaft fatigue.
What is the purpose of double block and bleed?
A double block and bleed is often used for a more positive isolation of a process fluid from other equipment. It normally consists of two block valves (Valves 1 and 2 in the pictures) and a bleed valve (Valve 3) to a safe location, consistent with local environmental regulations.
What is block valve?
Block valves are, as their name suggests, valves that are used to totally stop the flow of liquid or gas through a pipe. They are generally either open or closed and should not be used to control the flow of fluid. Different types of block valve include gate, ball, butterfly, plug, and needle valves.
How does a trunnion ball valve work?
How do Trunnion Mounted Ball Valves Work? Trunnion mounted ball valves are quarter-turn valves. This means you need to turn the actuator on a 90-degree angle to turn the valve on or off. Once the actuator is turned the ball rotates so that the bore faces the pipeline and medium can flow freely.
What is the difference between trunnion and floating ball valves?
The ball in a trunnion ball valve is supported by the stem and trunnion, reducing the operating torque, while the seats are spring loaded. In a floating ball valve, the ball floats and the seats are fixed while the ball is only supported by the stem.
What is the purpose of a double block and bleed?
How does a trunnion mounted ball valve work?
Trunnion-mounted ball design feature a “trunnion” anchoring at the top and bottom of the ball. This design provides a positive seal on both downstream and upstream seats, regardless of pressure, allowing for Double Block and Bleed, or Double Isolation and Bleed function.
Why do you need two bleed valves in a trunnion?
It requires two in-line isolation valves and a bleed valve used to drain or vent trapped fluid between the two closure elements in order to safely isolate the downstream pipe. This feature can be achieved with one single valves complete with a bleed port between the obturators.
How does a double block and bleed L & T valve work?
Double Block and Bleed L Valves offers Trunnion-mounted Ball Valves (TMBV) that conform to API 6D. The valve, in closed position, blocks flow from both valve ends when the cavity between the seating surfaces is vented through a bleed connection provided on the body cavity.
What are the advantages of a ball valve?
Advantages of a ball valve include Fast shut off, only a 90-degree turn required to close the valve. The opened or closed state of the valve can be easily detected by position of the handle. The Ball Valve provides tight seal, even after long periods, utilizing soft sealing components.
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