How do you select O-ring groove size?
Rod Gland Seals: The o-ring OD should be slightly larger than the ID gland depth (max 2%) External Pressure Face Seals: The o-ring ID should be slightly smaller than the gland inner diameter (Gland ID) (max 5%)
What is groove in O-ring?
STANDARD AS568B O-RING GROOVE DESIGN The three main types of standard groove designs are Industrial Static, also called Radial, Industrial Reciprocating, also called Dynamic, and Face Seals also called Axial or Flange. Radial and Dynamic seals require the presence of a diametrical clearance gap for installation.
Why groove width is necessary in O-ring?
Experimental analysis and experience have shown that elastomer o-rings must always be smaller than the grooves they fit in. If the o-ring volume approaches the groove volume, forces increase and shearing failures become apparent. To minimize forces, the o-ring should never be larger than 85% of the groove.
How do you choose an O-ring cross-section?
A thicker seal has more cross-section to withstand the movement and will theoretically handle more cycles than a thinner cross-section. A thicker seal will also have more stability in the groove and be less prone to rolling. However, thick seals will also have more friction in dynamic applications.
How do you spec an O-ring?
How to Measure O-Rings
- Place the O-ring on a clean, flat, level surface.
- Determine the inside diameter by using a ruler to measure from one inner edge to another.
- Use a ruler to measure the diameter, from one outer corner of the O-ring to the other outer corner.
- Finally, measure the cross-section.
Is standard for O-ring design?
AS568B STANDARD O-RING GROOVE DESIGN The three main types of standard groove designs are Industrial Static also called Radial, Industrial Reciprocating also called Dynamic, and Face Seals also called Axial or Flange. Radial and Dynamic seals require the presence of a diametrical clearance gap for installation.
How do you measure internal O-ring groove?
Place the O-ring on a clean, flat, level surface. Determine the inside diameter. Use a ruler or calipers to measure from one inner edge to another. To measure the outside diameter, use a ruler or calipers to measure from one outer corner of the O-ring to the other outer corner.
How much crush does an O-ring need?
Compression should not exceed 3% of the O-ring diameter. Stretch for a smaller O-ring should not exceed 5%.
How do you spec O-ring?
Can O-rings be used in non circular groove patterns?
Can O-rings be used in rectangular or non-circular groove patterns? This question comes up weekly, and the answer is a resounding “Yes!” however there are definite guidelines we want to follow. A non-circular face seal footprint might also be called a racetrack groove, a wandering groove or a custom plan view.
What is O-ring groove design?
Designing the parts of an application where o-rings will be applied is broadly termed “o-ring groove design”. In order to seal properly, the o-ring has to deform in the application by being compressed and stretched in any number of ways. The design of the groove where the o-ring sits plays a major role in how the o-ring performs its sealing role.
What is a dovetail groove on an O ring?
DOVETAIL O-RING GROOVE DESIGN Dovetail grooves are used to hold the O-ring in-place on a face seal groove during during assembly and maintenance of equipment. An undercut or dovetail groove has proven beneficial in many applications to keep the o-ring in place.
What does an O-ring groove look like on a piston?
One of the faces will be completely smooth and one will have an o-ring groove cut into it; depending on your application you can have the groove be cut in either the piston or the bore. The groove shape is very similar to that of face seals.
What is the fourth table for O-ring groove design?
Lastly, the fourth table is for dovetail groove design. These o-ring groove design guides offer default dimensional guidance for basic o-ring groove design applications. Flange/Face Seal A flange or face sealis static and will not have a gap between surfaces, eliminating any design issues associated with extrusion.