Shaft Sealing

Compression Packing

Packing Material

New Packing

Static seal is formed at the ends of the packing rings and outside diameter of the

stuffing box.

Dynamic seal is formed between the shaft or shaft sleeve.

After installation

Material should be resilient to compensate for installation variables.

Packing should be adjusted to control leakage.

Stuffing Boxes

Packing Pressure distribution

Stuffing Box Packing

Lantern Rings

Mechanical Shaft Seal

Mechanical Seal

Mechanical seal

Single Seal

Double Mechanical Seal

Double Mechanical Seal

NON-CONTACTING GAS LUBRICATED SEALS A sealing concept has its origin in gas sealing

technology developed for gas compressors in the mid-1970s.

Development of this technology for pumps was accelerated in the early 1990s as a way to control emissions.

Gas, rather than a liquid, must be used as a barrier fluid

one of seal faces must be designed with a lift mechanism.

Spiral groove seal face

LIFT MECHANISM

Can take the shape of a spiral groove, an L-shaped slot, or a controlled wavy surface.

When the shaft turns, pressure builds up in the seal faces. which causes the face separation.

Face separation is very small and could be measured in nanometers, which enables a small amount of gas to flow across the seal face.

Benefits

The only heat that is developed is from the shearing of gas at the seal faces.

The small amount of gas flow helps cool the seal faces.

The preferred seal for heat-sensitive liquids.

Applications

Pumping liquid near its vapor pressure.

The amount of heat generated would require too much cooling to prevent the liquid from flashing.

Allowing the liquid being sealed to flash to a gas and use a non-contacting gas lubricated seal.

For dangerous liquids a tandem seal is utilized.

Bearing