resulting from regulator or other component failure, restricting flow in a system in order to assure adequate pressure relief valve sizing and system over pressure protection, or restricting flow from bulk sources such as a water main.
This is done by first determining the flow through the same RFO at the required pressure with a reference gas and then adjusting the specific gravity accordingly.
In the natural environment, large orifice plates are used to control onward flow in flood relief dams.
In these structures a low dam is placed across a river and in normal operation the water flows through the orifice plate unimpeded as the orifice is substantially larger than the normal flow cross section.
Flow is then held back behind the low dam in a temporary reservoir which is slowly discharged through the orifice when the flood subsides.