'O' Rings

‘O' rings play a vital role in making the equipment, in which these are used, leak proof. ‘O' rings are engineered from a variety of elastomers for different applications. Some of the critical application are viz. Cylinder-liner rings for diesel engines and sealing systems in aircraft engines. 'O' rings can be designed for both static as well as dynamic applications. We have the facility to design an 'O' ring as also to manufacture it in bulk as per customers' specifications. The following parameters are required to select the right material for the 'O' ring as also to determine its correct size :-

Washers can be custom manufactured in different sizes and shapes at no extra cost for practically any purpose. Our range of washers are well accepted by clients for its superior make and high quality.

1. Fluid to be sealed.
  2. Nature of application.
  3. Lubricant used.
  4. Working temperature.
  5. Minimum and maximum and working fluid pressure. 
  6. Speed of shaft or frequency of reciprocating parts. 
  7. Type of finish on metal parts.

O’ RINGS

1. Used predominantly for sealing of stationary machine parts against liquid and gaseous media.
2. Available for stock in all standard sizes and in various qualities of material and of material hardness.
3. ‘O’ Rings for special uses in particular dimensions, special forms and special material mixtures.
4. Support rings, spiral back-up rings and USIT-Rings in standard versions and customer-specific versions.

STATIC SEALING

‘O’ Rings can be used for sealing static parts of machinery, i.e., for static sealing. With correct installation and proper choice of material, pressures up to 1000 bar and more can be sealed. The dimensions of the housing depend on the thickness of the ring used and on the given application. The hardness of the O-Ring material should not be less than 80 Shore A for pulsating pressures. The hardness of the material is chosen depending on the prevailing pressure and on the specified tolerances (gap widths). We recommend the following grades:

DYNAMIC SEALING

With dynamic sealing, a distinction is made between the use of O-Rings in hydraulics and pneumatics. On account of frictional resistance, the deformation is kept smaller in dynamic sealing than in static sealing. Good lubrication by the medium to be sealed in the case of hydraulics, or by an oil atomizer in the case of pneumatics, reduces frictional losses and wear. We recommend the following grades:

TOLERANCE FOR ‘O’ RINGS

O-Rings are made to very close tolerances. The indicated values apply only to O-Rings made from standard material. Materials of different base (elastomers) polymers or different hardness, deviations from the listed values can occur due to different shrinkage behavior, although these are normally so small that they have no effect on the intended performance of the O-Ring.

INSTALLATION OF ‘O’ RINGS

The entire system should be cleaned to remove dirt and fabrication detritus before the installation of O-Rings. O-Rings should not be pulled over sharp edges, stepped shafts, screw threads, grooves and the like. It is advisable to cover sharp edges during fitting in order to avoid damage to the O-Ring. The O-Ring must not be allowed to become twisted in its locating groove. Short-term stretching during fitting is permissible. Time must be allowed however for the ring to undergo elastic recovery after fitting. Care is necessary when fitting piston seals or shaft seals having external diameters below 10 mm because of the percentage enlargement. The use of a fitting mandrel or a fitting sleeve is recommended.