Strainers are installed inline to clean debris out of the fluid moving through a pressure vessel to avoid it damaging expensive downstream equipment like pumps. As the strainer does its job the strainer will begin to accumulate debris, and if it accumulates too much material, or the strainer is not periodically cleaned, the pressure in the strainer can become too great and it can damage the strainer and if undetected, can potentially damage the downstream equipment it was installed to protect.
Regularly scheduled cleaning is the best way to avoid damage. The challenge for many of our customers is that it can be difficult to anticipate how much debris may need to be removed over any given period because the source may not be consistent.
A Differential Pressure Assemblies can be an integral part of a design in these instances. A differential pressure gauge will measure the difference in pressure between two points. In the case of our strainers it will measure the difference between the pressure of the fluid on the inlet side of the strainer and again on the outlet. If the difference is too great, the strainer needs to be cleaned.
While you could install two pressure gauges, one on each side of the strainer, it would require someone to watch two gauges and determine the difference. Obviously, a differential pressure gauge makes the whole process much easier, and less susceptible to an error in calculation.
You can install a pressure differential assembly on any Sure Flow strainer, including our simplex strainers which would have just one strainer inline within a process system. But they are much more common in our dual basket strainers.
Our dual basket strainers are designed for applications where flow cannot be interrupted to service the strainer basket. Rather than stopping the line to clean and replace the basket, the dual basket strainer allows for flow to be redirected through a second basket while the initial basket is serviced.
The changeover is accomplished by use of a hand wheel (or lever) operator on an isolation valve, usually a butterfly valve. The timing of the changeover is made easier by a pressure differential gauge because it will indicate to the operator when the pressure on the inlet is too high, indicating that it needs to be cleaned or replaced.
Here are differential pressure gauges installed on a ‘simplex’, or single high-pressure basket strainer:
Here are some samples of pressure differential gauges on dual basket strainers: