Basic Requirements and Tips for Choosing and Using Oil Seals

Nov 23, 2015 Oil Seals

The oil and gas industry comprises some of the most dangerous applications. It involves the use of aggressive chemicals, such as amines, sour oil and gas, hydrocarbons, and polar solvents. Equipment used in this industry includes mud pumps, compressors, blowout preventers, and drilling risers and valves.

Pressures handled by the equipment increases up to 50,000 PSI. The equipment is exposed to a variety of elements and contaminants. These include sea water, drilling mud, steam and oil mixtures, and vibrations.

The success of an oil or gas unearthing operation depends a great deal on the equipment that is used. Hence, the oil seals used for the equipment need to be tough, performance driven, and durable.

Common Requirements for Oil and Gas Seals

The design of the oil seals will differ depending on the equipment and application they are used in. However, there are a few common points, which all customers can keep in mind.

The elastomer used should be able to resist high temperature up to minimum 600^o
Seals that come in contact with metals should be resistant to temperatures up to 2000^o
Tolerances need to be at least +/- .001ʺ.
When installing the oil seals, it should never come in contact with the metal shaft. If it does, then the seal will wear off in a few hours.

General Manufacturing Materials

Once you understand the application requirements, you will be in a better position to choose the material with which you can manufacture the oil seal. Luckily, there are a variety of sealing materials, which can be used.

Silicon
Nitrile
Poly Acetal
Polyurethane
Fluorocarbon
Fluoro-Silicone
Ethylene Propylene
Nitrile Buna Rubber
PTFE Filled Polyamide
Fluoroelastomer (Viton)
Molecular Weight Polyethylene
PolyTetraFluoroEthylene (PTFE)

Tips when using Oil Seals

The oil seals can provide the performance that you are expecting if you keep these tips in mind.

Use a non-molybdenum based grease on the seals, as it enhances the seal’s lubrication.
PTFE seals are the only exception to the previous point. Grease or oil should not be applied to PTFE seals; they must be kept dry.
Generally, the sealing lip protected by a plastic sleeve, which can be used as an assembly aid. If the sleeve needs to be removed, use special tools recommended by the seal manufacturer for installation.
The shaft should not comprise any sharp chamfers. If any chamfers are seen, have them removed.

Understanding the basic requirements of oil seals can help you to make a better informed decision as a customer. The above mentioned tips can help ensure consistent seal function and performance.