Originally Posted by
Rick
There are legitimate reason as I'll explain.
The relief valve is a type of valve used to control or limit the pressure in a system or vessel which can build up by a process upset, instrument or equipment failure, or fire. The pressure is relieved by allowing the pressurised fluid to flow from an auxiliary passage out of the system. The relief valve is designed or set to open at a predetermined pressure to protect pressure vessels and other equipment from being subjected to pressures that exceed their design limits. When the pressure setting is exceeded, the relief valve becomes the "path of least resistance" as the valve is forced open and a portion of the fluid is diverted through the auxiliary route. The diverted fluid (liquid, gas or liquid-gas mixture) is usually routed through a piping system known as a flare header or relief header to a central, elevated gas flare where it is usually burned and the resulting combustion gases are released to the atmosphere. As the fluid is diverted, the pressure inside the vessel will drop. Once it reaches the valve's re-seating pressure, the valve will re-close. This pressure, also called blowdown, is usually within several percent of the set-pressure.
As a note of explanation, the elevated gas flare is usually only experienced when a source of ignition such as a BIC lighter is in proximity to the flare header or relief header. This is usually accompanied by a rich source of hops and, sometimes, hard boiled eggs.
It's very scientific.
