HP draw of packing vs mechanical seals
HP draw of packing vs mechanical seals
(OP)
How do you calculate the horsepower draw of packing versus mechanical seals?
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HP draw of packing vs mechanical seals
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RE: HP draw of packing vs mechanical seals
Mech seals use 2 contact surfaces. You would have to know all the info on the seal and operating conditions. Best to contact your seal vendor and see if they have a value.
"If A equals success, then the formula is: A = X + Y + Z, X is work. Y is play. Z is keep your mouth shut."
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RE: HP draw of packing vs mechanical seals
Although as sprintcar said the power loss is dependant on the seal face design / contact area, running conditions and amongst other things the spring load.
However the graphs can give you a ball park figures for losses.
Since John Crane has already been mentioned - in their general mechanical seal catalouge these graphs are towards the back that cover this.
RE: HP draw of packing vs mechanical seals
A properly packed stuffing box will have low friction loss, therefore a low power consumption, an overtightened gland, resulting in high friction of the packing on the shaft will increase the power consumption and also accelerate the wear on the shaft / shaft wear sleeve. Therefore the power consumption of a gland / stuffing box is mainly a maintenance problem.
The decision to use a packed stuffing box or a mechanical seal is usually based on other considerations than power consumption.
Also if you are looking at overall power consumption - don't forget to add in the cost of pumping, collecting and processing any sealing water supplied to the packing or mech. seal.
Naresuan University
Phitsanulok
Thailand