1 reply to this topic

[m42364236k]

dears 

 

i have one question

 

in the suction line of the plunger type pump we have the strainer with differential pressure indicator ,but up stream and down stream of this strainer and also in the suction line of the compressor we do not have any pressure gauge 

 

do we need to add one pressure gauge on this line

 

and also we have same problem in in let of heat exchanger ,we have the filter with PDIT but in the line we do not have any pressure gauge,

 

 

THANKS

 

MIKE

[samayaraj]

hi,

 

For pump, if strainer getting chocked, pressure drop across strainer will rise and flow will be reduced. This will reduce the NPSH(A) to the pump. So, to restrict the pressure drop within the limit, we need a diff. pressure indicator/switch/transmitter to initiate a alarm or trip action to the pump.

 

For heat exchanger, tube side liquid strainer DP indicator/switch/transmitter is required to ensure the strainer is not chocked and to provide sufficient flow to take care of the heat load.

 

So you no need to have pressure gauge in suction of line until there is a need. You can also connect two pressure gauges one at the upstream and other at the downstream of strainer. The same job is done in a diff. pressure indicator.

 

In general, for compressors, discharge pressure is more important. Hence, suction pressure gauge is not required.

 

 

#Samayaraj

Edited by samayaraj, 16 July 2014 - 06:43 AM.