Sealing Devices, Inc.
Gaskets

 

Compressed Sheet Gaskets
Spiral Wound Gaskets
PTFE Gaskets
Flexible Graphite Gaskets
EMI Shielded Gaskets

  

Gaskets are materials that seal between two different surfaces, under compression. The sealing is a result of the compressive forces created by sufficient bold load, and also works to fill the imperfections on the mating surfaces to be sealed. Key factors involved in choosing a suitable material for a given gasketing application include:

Temperature - possibly the most important factor in choosing a gasket material. When higher temperatures at the gasketed joint need to be sealed, the potential choices are quickly eliminated. If the system operating temperatures approach a gasket materials max. continuous operating temperature threshold, the next best material should be chosen.

Chemical compatibility to the media to be sealed against (including flushes and system cleanouts). There are many different fluids and gasses to seal against, and many different choices of gasket materials to seal against them.

Pressure at the gasketed joint. The internal pressure of the fluid should be a determining factor in choosing a sealing material. If severe cycling or pressures changes occur frequently, a more robust material may be required.

Application - this includes all factors such as the number, grade and size of bolts to create compression, the surface areas of the sealed joint.

Because pressure and temperature are so closely connected, it is often effective to consider them together by measuring Pressure x Temperature or PXT value. Review the specifications of the material you are considering - if they are both near the max. continuous operating limits of the application, a more robust material should be used.

An important factor to consider in selecting materials is that most testing for OEM products is conducted under laboratory conditions. Actual field environments must be considered before a recommendation for materials can be made.

Compressed Sheet Materials - Common sealing materials include for die-cut, compressed sheet gasketing: compressed non-asbestos, vegetable fiber, neoprene, nitrile (buna-N), red rubber.

> Bolt Torque Values for ASME B16.5 raised face flanges, with A193 grade B7 bolts, compressed sheet recommendations from Garlock Sealing Technologies. Class 150# and 300#. (External link to Garlock.com)



Spiral Wound (semi-metallic) gaskets
- Resiliency and strength make spiral wound gaskets a good choice for a variety of applications and environmental conditions. They are made from winding a thin strip of metal wire, with soft fillers added to create an effective seal, and often have an outside centering ring, with an inner ring to offer additional radial strength.

Spiral wound gaskets have markings that indicate the manufacturer, the winding and filler materials, the pipe size (nominal), and the materials that the inner and outer rings are made from. The markings conform to ASME B16.20.

PTFE
PTFE - One of the most chemically-resistant materials available, PTFE can fit the bill for extreme sealing with sheet gasketing, gasket tape, joint sealant, and universal gasket configurations. In addition to resisting most chemicals, the expanded PTFE gaskets are outstanding at resisting creep and cold flow. There are also gaskets created specifically for low bolt load, or for use in sealing fragile pipe flanges.


Flexible Graphite for high temperatures, and heat dissipation.
> More Info on Grafoil®


EMI Shielded Gasketing and a variety of packings and different sealing sets.
> More Info

 

Call us at 800-727-3257 to determine your the correct compressed sheet gasketing material for your next sealing project.

   
 

Sealing Devices
 Customer Service: (716) 684-7600
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