NAK Australia Precision O Rings

Dynamic Applications

	Technical Information
	O-Rings, Kits & Cord
	Static Applications
	Dynamic Applications
	Running Surface
	Installation Instructions
	Compound Hardness
	Pressure Sealing
	O-Ring Materials
	BS 0 Series Size Charts
	BS 1 Series Size Charts
	BS 2 Series Size Charts
	BS 3 Series Size Charts
	BS 4 Series Size Charts

Dynamic Applications

Sealing the reciprocating piston of a hydraulic cylinder in a housing. The O-Ring is mounted in a rectangular groove on the outside of the piston. The depth of the groove should be such that the O-Ring shows a little above the groove. When the piston is installed in the cylinder, the O-Ring will be compressed 10-15%, so that an effective amount of sealing capacity will be obtained. The sealing is based on the elasticity of rubber and constructional data is listed elsewhere in this information sheet.

Sealing Rotating Shafts and Reciprocating Rods

The O-Ring should be installed in a groove in the housing. The depth of the groove should be such that the O-Ring rises a little above the groove. When the shaft or rod is mounted, the O-Ring will be compressed 10-15% so that an effective seal will be obtained.

The application of O-Rings for sealing rotating parts is not advisable. If it is necessary to use a compact sealing element in such cases, we recommend the application of a Quad Ring or other sealing element that is more suitable.

Choosing an O-Ring for Dynamic Parts

Cross Section Ų	Rod Cylinder Ų
1.6	0-13mm
2.4	13-25mm
3.5	25-40mm
5.3	40-115mm
7.0	>115mm

Always take the maximum cross section that the available room permits. Rubber behaves like water and consequentially cannot be compressed. When O-Rings rotate with the shaft the rubber is apt to "wind". When applied to a piston it may "twist".