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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1

What is the rule of thumb for leakage in a compression packing?

A rate of 40 - 60 drops per minute leakage.

2

Where are mechanical seals never permitted?

On pumps used for fire safety.

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

3

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

4

Where is the primary sealing point?

Between the stationary face and the rotating face.

5

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