A Guide to Select Oil Seals for Your Industrial Application

An oil seal is a type of seal used in various industrial equipment to close the gap between its moving and non-moving components. These oil seals help prevent lubricant leakage at high pressures and block foreign components from entering the machinery. With such an important role to play, these oil seals must be chosen carefully. This post discusses the types of oil seals and also guides you through the important factors to choose an appropriate oil seal for your industry.

Types of Oil Seals – Based on Materials

There is a wide range of seals to select according to the type of material. Some of the types of oil seals are as follows:

Rubber Oil Seals:

Rubber seals are the most common types of sealing solutions preferred for tight sealing. Rubber seals are corrosion resistant and are used in both high and low-pressure applications. Nitrile, polyacrylate, Viton®, silicone, and polytetrafluoroethylene are a few common types of rubber materials used for this purpose. Each material possesses the typical capability, so, you must choose the rubber material carefully for your application.

Metal Cased Oil Seals:

These seals feature stamped metal cases with an elastomer bonded sealing lip. Carbon steel is the metal used for making the case. The case protects the lip seal during installation. Metal encased seals are generally used for high-pressure or high-temperature applications.

Leather Oil Seals:

These seals possess good running properties and are generally preferred for abrasive applications. The seals are usually used for shafts that possess surface roughness higher than rubber seals.

7 Important Factors to Consider When Choosing Oil Seals

With varieties of seals available, choosing the right seal for application can be a daunting task. The following factors will help make the right selection.

Lubricant: If choosing lubricated seals ensure they are continuously lubricated with oil that possesses appropriate viscosity required for the application and the lubricant is compatible with the elastomer material of seals.
Shaft Finishing: A good surface finishing of shafts gives a very effective oil sealing. The ground or polished shafts with concentric finish marks provide the best sealing that prevents leakage even during the shaft rotations. Hence, it is important to make sure that the shaft finishing is well maintained.
Shaft and Bore Tolerance: The seals must be strong enough to tolerate the pressure and vibrations caused by shaft and bores. The authenticity of metal and elastomer material is something that makes the shaft and bore tolerance possible. Therefore, check if the material meets these requirements before buying the seal.
Shaft Hardness: The life expectancy of a seal is measured on the basis of the hardness of its shaft. A shaft must possess a Rockwell hardness of 30 or above. When a seal is exposed to abrasive contaminants or high pressure, this RC hardness protects the seal from getting damaged. Hence, it is an essential factor.
Temperature: The temperature of the process should not exceed the temperature of the seal elastomer. Any increase or decrease in temperature may affect the sealing capability of the seal. Hence, it is an important point to be considered.
Pressure: Most seals are designed for applications where they may be subjected to pressures as low as 8 psi. However, if they are subjected to even low pressures then pressure relief must be ensured.
Shaft Speed: Shaft speed depends on many factors including shaft finish, its concentricity, the type of liquid being transferred, and the type of oil seal material. So each of these factors must be considered to achieve a maximum shaft speed.

In addition to the above-given factors, sourcing high-quality seals from a trusted manufacturer are quite important. SSP Seals provides high-quality oil seals for industrial applications in automotive, oil and energy, and other sectors. The company can provide seals made of a wide range of materials including PTFE, Viton, Silicone, Nitrile, and so on.

Oil Seal, Shaft Seal, Rotary Seal, stainless steel oil seal, PTFE oil seal

Oil Seals (Rotary Seals)

Oil seals (also known as rotary seals or shaft seals) cover a wide range of applications ranging from domestic equipments to automotive and power plant machinery, industrial pumps, gas and aircraft turbines and compressors.

If yours is a modern system, the surface speed can go up to 30 m/s and operating temperature can be as high as 250 degree Celcius. For these type of oil seals, our general purpose high performance oil seals can be employed. When the speed is increased up to 90 m/s, the lip will be produced using PTFE based compound to reduce heat generation. For high pressure applications, we offer a wide range of oil seal profile made using PTFE based compounds.

Here at Advanced Sealing Devices, we make and design reliable oil seals for your demanding tasks. If the oil seal is not selected properly, then even a few percents of leakage can be inconvenient and incur expenses to a large number of users, as well as cause environmental pollution. Note that the oil seal is not only to seal lubricating oil, it can also be used to seal other fluids such as water, foodstuff and chemicals. We understand that the reliability and reputation of your system depends on the well functioning of these oil seals.

Standard oil seals operate in a splash environment with no pressure or little pressure as low as 0.3 – 0.5 bars. If you have a higher pressure requirement, contact us and we can provide you with a different type of oil seal design. If a standard type of oil seal is used in a high pressure situation, lip distortion and wear will occur. This will shorten the lifespan of the oil seal and create unnecessary downtime. If your housing tolerances are not controlled as closely as standard housings, we can make the outer casing of oil seals with special profile so that the oil seals can seat properly in your housing before the assembly press tool is removed.

If you application is such that the lubricating liquid is not continuously available, or the operating temperature, fluid compatibility, the speed and pressure are of a more demanding nature, then we can make oil seals using stainless steel outer casings with various pure and filled PTFE lips (type ASD SS-PTFE). This type of oil seal is now widely used by our customers in the automotive and transmissions industry. A stainless steel casing with a PTFE lip oil seal will support more highly rated machinery and allow longer oil change intervals. Our ASD SS-PTFE type is particularly suitable for dry running application, for example, an engine may run dry for some period during startup until oil splash is available especially after a long period of storage or transportation. There are certain design aspects that are required in your system before using our ASD SS-PTFE type oil seal; contact us and we will advise you on this aspect. The following are some examples of stainless steel oil seals we make for our customers.

Beside oil seals, we can also make sealing devices which seal on the radial face of your system, as opposed to the axial face for oil seals. With this type of seals, your shaft surface finish can be less critical and the seals can operate with minor runout and misalignment.

Various Types of Precision Oil Seals

In making oil seals, we employ modern polymeric seal materials and we rely on our good understanding of the sealing mechanism that occur at the sealing interface. We will thus provide you with reliable oil seals and also to enhance protection of the environment. We offer the following types of oil seals:

General Purpose High Performance Oil Seal
Rubber Fabric Oil Seal
Rotary V-Seal
PTFE O-Ring Energised Oil Seal
PTFE Metal Case Oil Seal
PTFE Spring Energised Oil Seal
PTFE Lip Oil Seal

General Purpose High Performance Oil Seal

Type

Code

Description

Applications

Speed (m/s)

Pressure (bar)

SAA

Metal casing and reinforced inner ring, sealing lip with garter spring

dust free application

0.5

SAB

Metal casing, sealing lip with garter spring

dust free application

0.5

SAC

Rubber casing and metal insert, sealing lip with garter spring

dust free application

0.5

TAA

Metal casing and reinforced inner ring, additional dust lip and sealing lip with garter spring

dusty application

0.5

TAB

Metal casing, additional dust lip and sealing lip with garter spring

dusty application

0.5

TAC

Rubber casing and metal insert, additional dust lip and sealing lip with garter spring

dusty application

0.5

KAA

Metal casing and reinforced inner ring, additional dust lip and rubber sealing lip

oil or dust seal, for dusty application

KAB

Metal casing, additional dust lip and rubber sealing lip

oil or dust seal, for dusty application

KAC

Rubber casing and metal insert, additional dust lip and sealing lip

oil or dust seal, for dusty application

VAA

Metal casing and reinforced inner ring, rubber sealing lip

oil or dust seal

VAB

Metal casing, and rubber sealing lip

oil or dust seal

VAC Rubber casing and metal insert, sealing lip oil or dust seal 10 - HATC-R Metal casing, sealing lip with garter spring and hydrodynamic rib, right rotation engines or transmissions 30 0.5 HATC-L Metal casing, sealing lip with garter spring and hydrodynamic rib, left rotation engines or transmissions 30 0.5 ACN Metal casing and reinforced inner ring, additional dust lip and sealing lip with garter spring; high pressure application 15 10 DAC Rubber casing, metal insert, and double sealing lips in opposite direction separating two types of oils 10 0.3 DAB Metal casing, and double sealing lips in opposite direction separating two types of oils 10 0.3 SACY Seal is fixed by clamping the flange, low friction reciprocating motion, for hydraulic control valves 10 6 SACJY With nylon backup ring for high pressure reciprocating motion with large shaft misalignment 10 6 TAC4 Rubber casing with metal insert reciprocating motion, designed to minimise lip deformation 1.5 0.3 TAB4 Metal casing reciprocating motion, designed to minimise lip deformation 1.5 0.3

Rubber Fabric Oil Seal

Type

Code

Description

Speed (m/s)

Pressure (bar)

RFS

Rubber fabric with spring sealing lip

0.5

RFSD

Rubber fabric with spring sealing lip and additional dust lip

0.5

RFSH

Heavy-duty steel mill roll neck bearing seal with steel band

5.0

RFSSP

Rubber fabric with spring sealing lip (split design)

0.5

Rubber fabric with springless sealing lip

0.5

RFD

Rubber fabric with double springless sealing lip

0.5

RFWRR

Rubber fabric rod wiper for rotary and reciprocating applications

0.5

RF0S

Rubber fabric with outside spring sealing lip

0.5

Rotary V-seals

Type

Code

Description

Speed (m/s)

Pressure (bar)

RS6

Most common profile, with sizes up to 2 metres, for gearboxes, electric motors and drives

RS6A

Compact v-seals, used in confined spaces

RS6B

Heavy-duty v-seals, for rolling mills

RS6C

Heavy-duty v-seals, for rolling mills, papermaking and large machine

RS6D

Heavy-duty v-seals, unique profiles to accommodate radial and axial support, for metals and paper mills

RS7

Wide body and tapered heel to hold ring on shaft firmly, for agricultural and automotive applications

PTFE O-Ring Energised Oil Seal

Type

Code

Description

Speed (m/s)

Pressure (bar)

RS10

PTFE sealing ring with preloading elastomeric o-ring element - for internal rotation

300

RS11

PTFE sealing ring with preloading elastomeric o-ring element - for external rotation

300

PTFE Metal Case Oil Seal

Type

Code

Description

Speed (m/s)

Pressure (bar)

TSM

Metal casing with machined PTFE sealing lip

TSF

Metal casing with formed PTFE sealing lip

TSFD

Metal casing with formed PTFE sealing lip and additional PTFE dust lip

TSF2

Metal casing with double formed PTFE sealing lip

TSF2D

Metal casing with double formed PTFE sealing lip and additional PTFE dust lip

TSMS

Metal casing with machined PTFE sealing lip and garter spring

TSMSD

Metal casing with machined PTFE sealing lip and garter spring and additional PTFE dust lip

TSM2S

Metal casing with double machined PTFE sealing lip and garter spring

TSM2SD

Metal casing with double machined PTFE sealing lip and garter spring and additional PTFE dust lip

PTFE Spring Energised Oil Seals

Type

Code

Description

Speed (m/s)

Pressure (bar)

TUcRT

Reduce friction; O-ring in OD, ID lip chamfered, canted-coil spring

210

TUvRT

Good sealing; O-ring in OD, ID lip chamfered, cantilever spring

210

TUcRR

Reduce friction; O-ring in OD of heel, ID chamfered, canted-coil spring

TUvRR

Good sealing; O-ring in OD of heel, ID chamfered, cantilever spring

TUcL

Reduce friction; OD flanged, ID chamfered, canted-coil spring

210

TUvL

Good sealing; OD flanged, ID chamfered, cantilever spring

210

PTFE Lip Oil Seal

Type

Code

Description

Speed (m/s)

Pressure (bar)

TC1RT

Sealing Lip (formed) with O-ring in OD

TC1SRT

Spring Energised Sealing Lip (formed) with O-ring in OD

TC2RT

Sealing Lip (machined) with O-ring in OD

TC1DRT

Sealing Lip (machined) with Dust Lip and O-ring in OD

TC3RT

Double Sealing Lip (formed) with O-ring in OD

TC3DRT

Sealing Lip (formed) with Dust Lip and O-ring in OD

What are Oil Seals - Guide to what an Oil Seal is used for

What are Oil Seals – A guide to Oil and Rotary Shaft Seals

Also known as a Rotary Shaft Seal, Shaft Seal, Lip Seal, Elastomeric Lip Seal or any variation of these. It is a simple device for excluding dust, dirt, water or any other contaminant whilst retaining lubricant in rotary shaft equipment. Generally, it has been developed as a means of protecting the bearings of rotating shafts.

In this blog, we attempt to highlight what are Oil Seals and the various Rotary Shaft Seals including Mechanical Face Seals, Water Pump Seals, Gland Packings, and V-Seals that are readily available.

What are Oil Seals and how do they work?

The basic principle of sealing is straightforward – the flexible lip is held against the rotating part (usually the shaft) whilst the casing (or O.D.) is pressed into the housing or bore and holds the seal in place. The sealing lip needs some form of lubrication to avoid overheating and is usually energized by means of a garter spring.

What are Oil Seals and the different types?

Many – too numerous to list, covering a vast range of designs, sizes, and materials suitable for a never-ending range of applications. Some designs conform to International Standards such as BS1399 and DIN 3760 for metric sizes and seal types, but the majority have been manufactured to suit particular applications – hence the enormous selection available. This blog is intended to assist in this selection and will consider seal type, materials, and sizes.

What are Oil Seals and how should they be ordered?

The simplest way is to know either the preferred manufacturers part number, the overall sizes of shaft diameter, housing diameter and bore depth, or use our brochure to establish the M Barnwell Services ordering reference. Many of the old traditional names of seal manufacturers have either changed or disappeared in this age of “acquisitions”. If no longer available, we will advise you and offer a suitable alternative seal, from stock whenever possible. If your concern is getting the right seals for the job, you will need to know something about the application as well as the overall sizes. If you have any doubts – contact us, we will help in your seal selection.

What materials are available?

Leather is probably the oldest of the lip materials still in common use, but the move towards mass production methods has seen a massive increase in the development of synthetic rubbers which lend themselves to accurate and repeatable injection and compression moulding. Nitrile (NBR) is still by far the most common elastomer for “normal” use, whilst Viton® (FKM/FPM) is rapidly replacing Polyacrylate (ACM) and Silicone (VMQ) for high-temperature applications. Viton® also has high resistance to abrasion and chemical attack making it a preferred elastomer. Recent developments in the use of PTFE for Rotary shaft seals has caused widespread interest particularly for high-speed shaft rotation or poor lubrication applications.

How are they used?

Once you have selected the most suitable seal available, considering the environment, temperature, shaft speed, pressure, lubrication availability, as well as the size, of course, the seal should be stored adequately and then fitted properly. Here are a few suggestions that could help:-

Storage and Handling

There is a British Standard laid down for the control of synthetic rubbers. BS 3574 (1989) helps to determine shelf life – for instance, Nitrile (NBR) and Polyacrylic (ACM) are Group ‘B’ rubbers and have a 7-year life, whilst Silicone (VMQ) and Fluoroelastomers (Viton®) are Group ‘C’ rubbers and have a 10-year shelf life. PTFE and Leather do not come into this category but like the others should be kept in the original packing for as long as possible away from direct light, dust, and humidity. Ozone, which can also be produced by battery-driven forklift trucks has a very bad effect on synthetic rubbers. Finally, protect the sealing lip – DO NOT hang the seals on nails, wire etc.

Installation

If the seal is being fitted to original equipment you may have some influence over the shaft and housing bore finish, but if you are replacing a worn seal you still need to take into account the condition of these 2 essential parts. Check for sharp edges and burrs – particularly on the shaft and housing chamfers or you could ruin the seal before you start up. If the shaft is too worn consider using an M Barnwell Services Shaft Repair Kit.