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The Online O-Ring Connection.
BD14581_.GIF (206 bytes) Material Selection Guide
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BD14581_.GIF (206 bytes) O-Ring Sizing Chart
BD14581_.GIF (206 bytes) O-Ring Gland Design
BD14581_.GIF (206 bytes) Fluid Compatibility Guide
BD14581_.GIF (206 bytes) O-Ring Failure Analysis
BD14581_.GIF (206 bytes) O-Ring Kits / Accessories
BD14581_.GIF (206 bytes) Semicon Applications
BD14581_.GIF (206 bytes) Request a Quote
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PO Box 1150
Seabrook, NH 03874
Fax# 603-468-3490

BD14581_.GIF (206 bytes)

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O-ring dimensions

Two dimensions define the size of an O-ring:  its inside diameter (ID) and its cross-sectional diameter (CS).  ( illustrated above.)

O-Ring Gland Design Charts
Select the type of seal below:

Static Radial Applications
Common Fixed Seal

Dynamic Reciprocating Applications
Moving Piston/Cylinder

Static Axial Applications
Face Seals

Metric Gland Design

Semiconductor Gland Design

 

O-Ring Gland Design Considerations

 


Proper Squeeze

•Compression expressed as a percentage of the free-state cross-sectional thickness:
    (O-Ring C/S) - Gland Depth
     (O-Ring C/S)
•Face Seal: 20-30%
•Static Male/Female: 18-25%
•Reciprocating: 10-20%
•Rotary: 0-10%

Pressure vs Clearance

•Excessive clearance can result in seal extrusion
Eccentricity & Side Loading
• Too much squeeze on one side and not enough on the other or none at all
•Can open too wide a clearance gap and result in extrusion of one portion of seal
Pressure vs Clearance Gap Chart

Gland Fill

•Gland volume vs. O-Ring volume
    (O-Ring Volume)
     (Gland Volume)
•About 25% void space or 75% nominal fill
•Need space in groove to allow for volume swell, thermal       expansion, and increasing width due to squeeze
•Narrower groove for sealing vacuum or gas
•O-Ring can get squeezed out into clearance gap or get squeezed in two directions

Stretch

    (Groove Diameter) - (O-Ring ID)
     (O-Ring ID)
•General rule is 0-5%
•Excessive stretch can overstress material
•Thins cross section and reduces % squeeze
•% cross section reduction due to stretch about half of the % ID stretch

Tolerances

•Have to be considered for O-Ring and the gland
•Affects squeeze and affects pressure rating
•Less a factor on larger cross sections

Surface Finish

•Seal material must fill in voids in surface.
•Static surfaces
   –32 rms to seal liquid
   –16 rms to seal gas
•Dynamic Surfaces
   –8 to 16 rms
•Too rough of a surface can result in abrasion or spiralling, even with a static seal

Sharp Corners

•Can cause damage during seal installation

 

Standard Sizes

The standard sizes used by allorings.com and other major O-ring manufacturers in the United States are defined by Aerospace Standard AS568A, Aerospace Size Standard for O-rings.  That document, published by the Society of Automotive Engineers, Inc. (SAE), groups most standard sizes under one of five cross-sectional diameters (or series).  Those standard sizes are also used for most military specifications.

allorings.com offers O-rings in all 369 standard sizes, including 20 sizes for boss seals listed under the 900 series.

Metric Sizes

Metric Sizes are available in most millimeter increments as well as many fractions.  Please contact us for pricing on Metric sizes.

Non-Standard Sizes

Non-standard sizes 26"ID or less in most materials can be produced with no tooling / set-up charges.  Please contact us with for pricing.

Material Selection Guide (Order Here) | 
O-Rings Explained  | O-Rings Sizing Chart | 
 | Fluid Compalibility Guide | O-Ring Failure Analysis | 
Home | Contact Us | Request a Quote |

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and Chemraz® are a registered trademark of Green Tweed


1998-2003  allorings.com Inc.   All rights reserved.

 
allorings_logo.gif (2918 bytes)
The Online O-Ring Connection.
BD14581_.GIF (206 bytes) Material Selection Guide
Place your order. Order Online Place your order.
BD14581_.GIF (206 bytes) O-Ring Sizing Chart
BD14581_.GIF (206 bytes) O-Ring Gland Design
BD14581_.GIF (206 bytes) Fluid Compatibility Guide
BD14581_.GIF (206 bytes) O-Ring Failure Analysis
BD14581_.GIF (206 bytes) O-Ring Kits / Accessories
BD14581_.GIF (206 bytes) Semicon Applications
BD14581_.GIF (206 bytes) Request a Quote
BD14581_.GIF (206 bytes) Contact Us

Special Offer! wpe1.jpg (4422 bytes)
Buna-N O-Ring Kits
$10.00
Click here for details

wpe1.jpg (1684 bytes)


allorings.com, Inc.

PO Box 1150
Seabrook, NH 03874
Fax# 603-468-3490

BD14581_.GIF (206 bytes)

Contact Us