With the exception of a PSV downstream, is there any other application where a restriction orifice should NOT be used?? I am refering mostly to code restrictions, although best practices would also be of interest. My service is in the oil and gas business only.
In general, restrictions, either a specially designed spool piece or a restriction orifice, should not be used as a means
of limiting the capacity of a pressurization path.In special cases, where large incentives (such as reducing the size of
the flare system) apply, a restriction may be used, provided that all the following conditions are satisfied:
1. A warning against unauthorized removal is provided by means of the following:
2. A warning sign plate welded to the restriction, and
3. A note in the relevant documentation (specification, flow diagrams, operating manuals, etc.) is provided.