Oil Seals

An Oil Seal is a combination of metal shell and elastomer vulcanized together to the designed dimensions having a sealing lip. This lip type seals are used for retaining fluid or grease in equipment employing rotating shafts.

 

In some instances,tha shaft is stationary and the housing rotates.Sealing of a lip type seal with low differential pressure is normally a result of a designed interference fit between tha shaft snd the flexible sealing element,which is usually fitted with a garter spring.

 

An interference fit between the outside surface of the seal and the housing bore surface retains the seal in the hosing and prevents leakage at the outer diameter.

 

More than one hundred standard seal profiles have been discovered.Few of the popular standard profiles are given to suit majority of the application.Varieties of metal to polymer combinations also available based on application media,temperature,weather condition,shaft speed and pressure.

 

Important Standard Rotary Oil Seal Types

 

 

 

A unique design and technology in polymer and polymer to metal bonding ensured to perform.We make products using Nitrile, Viton, Silicon, Polyacrylic, EPDM, Neoprene, Butyle, Hyplone, Vammac, Zetpol and NR.

 

HOW TO SELECT A SEAL?
 

It is purely based on the application of the installation. You can select the seal by referring the table given below which is matrixed based on the polymer and application conditions. While selecting the seal consider the function, media and environment of the seal being installed. In order to select various sealing conditions.

 

Table No: 1 Gives ELASTOMER INFORMATION

 

PROPERTY

Base polymer and its code

Nitrile

Polyacrylic

Silicon

Fluoroelastomer

 

N

P

S

v

Temperature

-350  C to 1200 C   -300 C to 1500 -600 C to 2000 C -350 C to 2000 C

Oil Resistance

Excellent Excellent  Good

Excellent

Acid Resistance Good Fair Fair Excellent
Alkali Resistance Good Not Suitable Not Suitable Fair
Water Resistance Good Fair Good Good
Heat Resistance Good Excellent Excellent Excellent
Cold Resistance Good Fair Excellent Fair
Wear Resistance Excellent Excellent Good Excellent
Ozone Resistance Good Excellent Excellent Excellent

 

Table No: 2 Gives MERITS AND DEMERITS

 

Polymer

Merits Demerits
Nitrile

Good resistance to petroleum  Oils, water, silicone oils, greases. Resistant to Glycol base fluids. Good abrasion resistant cold flow and tear resistant.

Poor resistant to ozone and weather.

Polyacrylic 

 

Good resistance to mineral oils Hypoid gear oils, E.P additives greases. Good ageing and flex cracking resistant.

Poor cold temperature limit  dry running and water resistant.

Fluroelastomer

 

V.Good temperature resistant.

Fair resistant to water, dry (Viton) running and low temperature application.

Silicon 

Wide temperature range application good ozone resistance. Resistance to compression set. Low resistance to hydrocarbon fluids like gasoline and paraffin fluids and steam above 50 psi.

 

ANOTHER CRITERIA FOR SELECTION OF SEAL

 

Table No: 3 Gives FLUID COMPATIBILITY

 

PROPERTY

                  Base Polymer and its code

Nitrile Polyacrylic Silicon Fluoroelastomer
N P S V

Engine oil

Excellent Excellent Good Excellent

Gear oil

Good  Good    Not suitable  Excellent
Turbine oil Good   Good Good  Excellent

Machine oil

Good

Good

Fair Excellent
Automatic Transmission Fluid Excellent Excellent Fair Excellent
Petroleum Base lubricating oil Excellent Excellent Fair Excellent
Gasoline Fair Not suitable Not suitable Good
Light oil Fair Not suitable Not suitable Good
Cutting oil  Excellent Good Fair Excellent
E.P Lubricants Good Excellent Not suitable Excellent
Water – Glycol Excellent Not suitable Good Good
Alcohol Excellent Not suitable Good Fair
20 % Hydrochloric acid solution Fair Fair Fair Excellent
30 % sulfuric acid solution Fair Fair Not suitable Excellent

 

SEAL NOMENCLATURE

    

All industrial application and general application calls for rubber OD seal type. Which is known as TC type. Another type commonly used is metal OD, mostly in automobile application which is known as SB or TB type. Supply  of SB ot TB type will be based on requirement.