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…

In the event of an imbalance in the volumetric flows in and out of a container, a change of pressure can result within the container. The flow rate entering and exiting the container can be determined using common engineering calculation techniques, either by evaluating the capacity of a single limiting source term or single piping component, multiple piping components in series, the limitations of a fluid driver, or the combined effect of the fluid driver and the intervening piping system. Several cases of overpressure scenarios are evaluated in this manner, including heat exchanger tube failure, inlet control valve failure, and inadvertent valve opening.

For heat input to two phase systems with a phase change, the vaporization of the liquid forms the basis for the required relief rate, ignoring the expansion of the individual phases. For these systems, the…

For heat input to two phase systems without a phase change, the expansion of the individual phases causes a displacement of the phase in contact with the relief device, and that displacement is the basis…

For heat input to single phase systems, the heat input, heat capacity, and cubic expansion coefficient are used to obtain a required relief rate. The relief requirements discussed below are for heating or cooling of…

When heat is transferred to a liquid that can vaporize, the phase change is usually the most significant contributor to the overall change in density, and any individual phase expansions are typically ignored. One key…

When heat is transferred to or from a single phase fluid, that fluid will expand or contract, and the isobaric cubic expansion coefficient is used to characterize that expansion. Usually this expansion coefficient is taken…

When evaluating the effect of heat input or removal from a closed system, the rate of heat transfer needs to be identified. Common heat transfer techniques, usually assuming a constant value, are employed while recognizing…

The transfer of heat into or out of a constant volume container results in an attempt of the entrapped fluid to change in overall density, leading to pressure increases or decreases. The change in fluid…

The Second Edition of the CCPS Guidelines for Pressure Relief and Effluent Handling was released recently, and we have finally had a chance to review the contents. Overall, the book has had a significant overhaul…