Mechanical Seals and Packing Flashcards Preview

Fourth Year Millwright 2018 > Mechanical Seals and Packing > Flashcards

Flashcards in Mechanical Seals and Packing Deck (5)
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What is the rule of thumb for leakage in a compression packing?

A rate of 40 - 60 drops per minute leakage.


Where are mechanical seals never permitted?

On pumps used for fire safety.

This is because when a mechanical fails, it fails completely.


What are the four components that make up mechanical seals?

1.) A set of primary sealing surfaces.
2.) A mechanism for holding the seal faces together to form a seal.
3.) A set of secondary seals (commonly known as shaft packing or insert mounts)
4.) Metal components -
Eg. Set screws, Springs, Drive lugs, Collars, Pins, Retainers And Snap Rings


Where is the primary sealing point?

Between the stationary face and the rotating face.


Where is the secondary sealing point?

At the outside or around the stationary face, by means of packing, Such as Gaskets, O-rings, and V-Rings