The offset pressure pipe sampler is used to take a primary process control sample from a pumped or pressurised line. For all pressurised lines of 250 NB and larger, the use of an offset centre pipe sampler to increase the representivity of the final sample is recommended.
There are two main variants depending on the specified use of the sample:
- If supplied with a continuous nozzle, then this sampler is suitable for supplying a sample to an on-stream analyser.
- If supplied with a recirculating nozzle then this sampler is suitable, along with a poppet sampler, for producing a shift or composite sample without the discard stream. It is an advantage to eliminate the sample discard stream as this in turn means less pipes and pumps required to return it to the process.
- These samplers feature a robust nozzle made from stainless steel and cast liner in polyurethane. The nozzle ensures that a sample is taken from the centre of the pipe, in a well-mixed turbulent zone.
- The recirculating nozzle ensures a fresh stream is directed to the measurement zone where the secondary poppet sampler is located.