Pressure Control
A valve used to control the pressure in a system or vessel which can build up by a process upset is called a relief valve. The pressure is released by allowing the pressurized fluid to flow from an auxiliary passage out of the system. The relief valve is designed to open at a programmed set pressure to protect pressure vessels and other equipment from being subjected to pressures that go beyond their design limits. When the set pressure is exceeded, the relief valve becomes the “path of least resistance”. The valve is then forced open and a portion of the fluid is diverted through the auxiliary route.
It is recommended that the outlet of the relief valve is in the open air in high-pressure gas systems. In systems where the outlet is connected to piping, the opening of a relief valve will give a pressure build up in the piping system downstream of the relief valve. This often means that the relief valve will not re-seat once the set pressure is reached. For these systems often so called “differential” relief valves are used. This means that the pressure is only working on an area that is much smaller than the openings area of the valve.
Related posts:
Follow Us On Twitter
