Tandem seal for pump and compressor
Tandem seal for pump and compressor
(OP)
Hi,
If I have a tandem seal for pump and a tandem seal for gas compressor, what I understand is that the primary seal will be drawn from pump or compressor discharge to the stuffing box, and the secondary seal could be water for pump (API seal plan 52) and nitrogen for gas compressor. I would like to know if the above is correct? And if so, my question is, does the secondary seal pressure must be higher than the pump or compressor discharge pressure in order to prevent the primary seal from 'leaking'?
Also, does any one know which website can I find the relevant information?
Thanks a lot!
If I have a tandem seal for pump and a tandem seal for gas compressor, what I understand is that the primary seal will be drawn from pump or compressor discharge to the stuffing box, and the secondary seal could be water for pump (API seal plan 52) and nitrogen for gas compressor. I would like to know if the above is correct? And if so, my question is, does the secondary seal pressure must be higher than the pump or compressor discharge pressure in order to prevent the primary seal from 'leaking'?
Also, does any one know which website can I find the relevant information?
Thanks a lot!





RE: Tandem seal for pump and compressor
Tandem seals in a Gas Compressor is diffierent to a Pump. This equipment does not use API Plan 52. You must treat these as two different applications. The compressor would normally have a Gas Panel that delivers clean N2 to the secondary seal and dry filtered Process gas to the primary seals. This will vary depending on application.
trust this helps.
RE: Tandem seal for pump and compressor
Thanks for your explanation. I must admit that I am not familiar with the seal plans for both pumps and compressor!
Regarding your seal plan 52 on pump, what should be the buffer fluid pressure? If this pressure is lower than the primary seal (which is taken from pump discharge and hence discharge pressure?), how will the buffer fluid be able to prevent the primary seal from leaking?
Regarding the compressor seal, is the nitrogen pressure be higher than the compressor discharge pressure (which in this case, discharge fluid also will be the primary seal)?
Please provide more information and explanation
Thank you very much for your help.
RE: Tandem seal for pump and compressor
Gas compressor tandem seals are different animals as mentioned, but there are similarities. You must keep in mind of course, that when discussing gas compressor seals of this type you are talking about a non-contacting seal design. The process gas will be applied to the primary seal; typically a lower pressure nitrogen sweep is applied the outer seal and leakage from both are sent to a flare. There are variations, but this would be the most common. A pressurized seal can also be used here, but you need adequate pressure differential over your sealed pressure (suction pressure typically in a beam type centrifugal compressor) for this to work.