The last years there has been a large increase in the requirements for flush rings, flush flanges, reducer flanges and complete assemblies with special constructions with valves and extension with related requirements.
The flushing flange or ring is used for flushing solutions combined with diaphragm seals. This type of flushing flange or ring is clamped between the process nozzle and diaphragm seal. It is used with flanged or pancake style remote diaphragm seals. Commonly, they have one or two threaded holes in the side of the ring called ‘flushing connections’.
It is unusual to order a calibration/flushing ring without flushing connections. However it can be used without, as a spacer or a heat dissipater. They’re sometimes called flushing rings, because the flushing connection on the side of the ring allows the user to flush out buildup on their process diaphragm. The main advantage is that you can perform this task without disconnecting the remote seal from the process flange. Sometimes they’re also called calibration rings, because the flushing connection on the side of the ring allows users to apply a known pressure source and consequently calibrate the unit against that known pressure. Next to that, flushing constructions can be made with needle valves and extensions.
The flushing ring should be seen as a diaphragm seal accessory that is carefully designed to optimize the use of the diaphragm seal in your process conditions, or to ease the installation and protect it against damaging during installation.