The steady-state techniques discussed in CCPS GPREH 2nd Edition §3.31 are usually conservative in nature when applied correctly. In general, some conservatism is desirable due to the variables involved in abnormal events that lead to…

A commonly encountered system involving both material accumulation and heat input is the low pressure tank. For fixed roof tanks, a vapor headspace is typically present above the residing liquid, and without credit for any…

The proper evaluation of some causes of overpressure for nonreactive systems involves consideration of both excess material entering/leaving the system and heat transfer within the system. Many causes of overpressure affecting distillation towers require this…

With the tube failure overpressure scenario deemed applicable and decision as to the geometry of the break made, an appropriate required relief rate calculation model can be chosen.1 Steady-state calculation methodology. These calculation models require…

The structural failure scenario is a special case of excess inflow.1 The method of estimating the flow through the break depends on the service and the specific type of equipment. After establishing the flow rate…

One of the flow limiting elements introduced in Excess inflow or outflow can be the fluid driver itself — the pump or compressor that establishes the maximum throughput available to the protected container at its…

For excess inflow into a system, the flow rate entering the system from a higher pressure source can be determined based on the flow limiting element between the high pressure source and the system of…

For excess inflow into a system, the flow rate entering the system from a higher pressure source can be determined based on the flow limiting element between the high pressure source and the system of…

In Orifice Flow for Subcooled Flashing Liquids and Orifice Flow for Two-Phase Fluids – Part 1, we outlined our effort to verify a calculation model for two-phase orifice flow using the data of Richardson, et…

We have continued our effort to verify a calculation model for use with determining the flow rates of two-phase fluid through orifices based on the data of Richardson, et al.1 In that work, they have…