Mechanical Seals
The start-up process for pumps can be a critical time when problems arise with the mechanical seals they contain.cfw oil seal
selected materials. The pump manufacturers do not necessarily give
instructions on the right procedures to follow to protect the mechanical
seals when the pumps are turned on and the seals can be ruined if the
proper steps are not followed. rubber sealing.For
example, most pumps are self-venting but that does not mean that the
stuffing box area is vented. To make sure the mechanical seals do not
run dry, the stuffing box must be relieved of air.
Sometimes a pump in a critical application will be hooked up to a
stand-by pump in case there is a problem. However, if the mechanical
seals in the stand-by pump are not made from the right elastomer, they
could have a tendency to harden, distort their shape or stick to the
shaft if the pump is not used for a long period of time. Obviously, then
when the stand-by pump is needed and turned on, the mechanical seals in
it will fail.cfw oil seal selected materials.
If you have mechanical seals that have failed, it is important to look
at them to determine what caused the failure. There are many factors
that cause failure:
Chemical Degradation: The mechanical seals may exhibit many signs of
degradation including blisters, cracks, voids or discoloration. It may
be honey combed, flaky or starting to crumble. In some cases, the
degradation is observable only by measurement of physical properties.ring seal.
Extrusion or Nibbling: The mechanical seals develop ragged edges (generally on the low-pressure side) which appear tattered.
Thermal Degradation: The seals may exhibit radial cracks located on the
highest temperature surfaces. In addition, certain elastomers may
exhibit signs of softening – a shiny surface as a result of excessive
temperatures.
Fretting Corrosion: This causes leakage at the secondary seals and will
cause problems with the sleeve directly beneath the secondary seal area.
This area will be pitted and shiny.
Vaporization: You will see places on the seal faces where vapor was blown out.cap seal. There will be chipping on the inside and outside diameters and the whole area will be pitted.
Oxidation & Coking: The mechanical seals will have a film or sludge
on the side that is exposed to the atmosphere. This not only can lead to
the seal faces wearing quicker than usual, but it can cause the seals
to want to hang up.cfw oil seal selected materials.
Thanks For sharing this useful information on Oil Seals .
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