Block and Bleed Valve
Definition - What does Block and Bleed Valve mean?
A Block and Bleed Valve, also known as double block and bleed valve, is a combination of one or more isolation valves (generally ball valves) and one or more bleed valves (generally ball or needle valves) in one single valve assembly. The functionality of the Block and Bleed Valve is to block the flow of oil or gas from one system and at the same time allow the flow of oil or gas from another system into the downstream network.
Petropedia explains Block and Bleed Valve
Block and Bleed valves can perform the tasks of multiple valves and thus they prove to be an economical solution for wide range of industrial applications. As per the API 6D specification for pipeline valves, block and bleed valve is a single valve with two seating surfaces. When it is in closed position, it gives benefit of a tight seal against pressure from both ends of the valve with a means of venting the cavity between the seating surfaces. However, as per OSHA (Occupational Safety and Health Administration) federation regulations, block and bleed valve can be described as the valve that can close a line, duct or a pipe by locking and closing two in-line valves and simultaneously opening and locking a vent valve in the line between the two closed valves.
Benefits of Block and Bleed Valves:
- It requires less space.
- Efficient pipeline design as requirement of multiple valves is not there as all valve components are house in single unit.
- It helped in replacing traditional pipeline engineering techniques.
- It is a cost-effective solution.