Mechanical Seals and Packing

Question 1

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

Answer 1

A rate of 40 - 60 drops per minute leakage.

Question 2

Where are mechanical seals never permitted?

Answer 2

On pumps used for fire safety.

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

Question 3

What are the four components that make up mechanical seals?

Answer 3

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

Question 4

Where is the primary sealing point?

Answer 4

Between the stationary face and the rotating face.

Question 5

Where is the secondary sealing point?

Answer 5

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