Mechanical Seal
Mechanical Seal
(OP)
Hi,
We have a situation where we operate three horizontally split case centrifugal pumps that are connected to the same suction line and discharge line. When operating under suction mode, the gland packing are known to leak air into the system. Usually it's one pump duty and two of the pumps on standby.
I have been told that to prevent air leak into the system, a flushing line that bleeds water from the pump volute and provides pressure on the packing gland can be installed. This should solve the air leak through the duty pump. However air would still leak into the pumps through the packing gland of the standby pumps.
Hence, i am thinking of mechanical seals on all three of the pumps. My question is how good are mechanical seals under very low or vacuum condition? Would low pressure in the pump push the two faces apart to leak air into the system?
Thanks for any information
We have a situation where we operate three horizontally split case centrifugal pumps that are connected to the same suction line and discharge line. When operating under suction mode, the gland packing are known to leak air into the system. Usually it's one pump duty and two of the pumps on standby.
I have been told that to prevent air leak into the system, a flushing line that bleeds water from the pump volute and provides pressure on the packing gland can be installed. This should solve the air leak through the duty pump. However air would still leak into the pumps through the packing gland of the standby pumps.
Hence, i am thinking of mechanical seals on all three of the pumps. My question is how good are mechanical seals under very low or vacuum condition? Would low pressure in the pump push the two faces apart to leak air into the system?
Thanks for any information
Talk To Other Members
RE: Mechanical Seal
Or actuate the valves which are there.
Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
RE: Mechanical Seal
Johnny Pellin
RE: Mechanical Seal
RE: Mechanical Seal
Johnny Pellin
RE: Mechanical Seal
Thank you for the response.
#littleinch - That is definitely one option. I will look further into that.
#JJpellin are you saying if we go with mechanical seals, flushing would need to be provided for all the pumps simultaneously? is that the case for pumps on your surface condenser system? There needs to be some sort of flow control to prevent high velocity water from damaging the mechanical seals?
RE: Mechanical Seal
Johnny Pellin
RE: Mechanical Seal
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)