Two-Phase Flow There are no precise formulas for calculating orifice area for twophase flow. The common convention is to calculate the area required for the…
Conventional Valve, Balanced-Bellows Valve, or Pilot-Operated Valve The corresponding equations for liquid flow are the following: Note that a preliminary orifice size must be determined…
The flow rate for gas through a given orifice area or the area required for a given flow rate is obtained by:
Back-pressure can affect either the set pressure or the capacity of a relief valve. The set pressure is the pressure at which the relief valve…
The flow of a compressible fluid through an orifice is limited by critical flow. Critical flow is also referred to as choked flow, sonic flow,…
These are thin diaphragms held between flanges and calibrated to burst at a specified static inlet pressure. Unlike relief valves, rapture discs cannot reseal when…
Pilot-operated relief valves use the pressure in the vessel rather than a spring to seal the valve and a pilot to activate the mechanism. Figure…
Balanced relief valves are spring-loaded valves that contain a bellows arrangement to keep back-pressure from affecting the set point. Figure 13-4 shows a cross section…
Figure 13-2 shows a cross section of a conventional relief valve and Figure 13-3 is a schematic that shows the valve’s operation. Convention al relief…
A vessel may be subject to more than one condition under different failure scenarios. For example, a low pressure separator may be subject to blocked…