Choosing the Right Gasket

Gasket Installation Guide

Download Installation Instructions for KLINGERŪ Gaskets

Please Note: you will require Adobe Acrobat Reader to View Gasket Installation Instructions, Approvals and Technical Data Sheets - Click Here to Download Acrobat Reader.

Correct gasket choice is an important step in the design of a process system as choosing the correct gasket from the beginning can result in significant savings due to longer gasket life, reduced gasket failure and lower leak rates.

This guide is included here to provide practical advice and recommendations on achieving optimum performance from asbestos free gaskets.

This guide is supplied as an initial reference only, and many of the theories behind the recommendations are not discussed in detail.

Possible Material Options are

  Class 150 Class 300 Class 400 Class 600 Class 900 Class 1500 Class 2500
Rubber¹
   
Klingersil C4243
     
Klingersil C4400
     
Klingersil C4430²
     
Klingersil C4500²
     
Klingersil C8200
     
Graphite SLS
     
Graphite PSM-AS
     
PTFE envelope³
   
Spiral Wound
 
maxiprofile
 
Sealex
   
  Suitable for use
  Suitable for use depending on temperature, pressure and media
  Not suitable for use
  • Not exceeding 10 bar pressure and usually for liquids only
  • Recommended Thickness 1.5mm
  • Insert type C4430

 


Other Considerations
Limitations in steam

Steam duty is perhaps the most common and one of the most arduous gasket applications. It is difficult in part because

  1. Steam is a powerful hydrolyser capable of changing the nature of many polymers and fibres.
  2. An increase in the pressure of saturated steam results in a corresponding increase in temperature. Gaskets under increased stress (ie higher internal pressure) in general require a reduced operation temperature.
  3. Many materials harden in steam leading, in some cases, to embrittlement. This is especially applicable to asbestos free calendered materials.

When discussing temperature limits in steam only approximate guide-lines can be given due to considerations such as

  • Flange design (ie spigot and recess is far better than raised face)
  • Gasket thickness (thinner gaskets perform better)
  • Required service life
  • Assembly techniques
  • Maintenance procedures
  • Degree of acceptable embrittlement
  • The use of jointing compounds in an assembly

Bearing these factors in mind we suggest that very careful consideration be given to the above parameters, especially where operation is near the borderline of the PT diagrams available on this website. If in doubt contact Klinger (technical_service@klinger.com.au) for technical advice.

Low Temperature Duty

The following conditions need to be met before determining suitability of materials at low temperatures.

  • The gasket is completely dry when installed
  • The flange is assembled at ambient temperature
  • The flange and bolt materials are suitable for low temperature use
If these conditions can be met the following minimum operating temperatures apply
Natural Rubber
-70°C
Neoprene Rubber
-40°C
Nitrile Rubber
-40°C
Viton Rubber
-15°C
PTFE envelope gaskets
-80°C
Klingersil C4500
-196°C
Klingersil C4430
-196°C
Sealex
-196°C
Spiral Wound gaskets
-196°C

Gasket Size
A general rule is that gaskets cut from a sheet (eg Klingersil, Top-chem, etc) can be successfully used at smaller diameters, lower pressures and/or lower temperatures. As diameter, temperature or pressure increase the use of semi-metallic gaskets are more common. This is largely due to the effect of hydrostatic end thrust in reducing stress on the gasket and increasing the chance of a blow-out.

As a general rule, special care should be taken for gaskets above 600mm diameter, or operating above 200°C or 50 bar.

Steps To Effective Gasket Choice
1. Determine the likely gaskets for your application (above)
2. Check Chemical Compatability of the possible Materials