PTFE Gaskets

Polytetrafluorethylene or PTFE is a polymer with an exceptional chemical resistance and is the most widely used plastic for industrial sealing. The only substances that attack PTFE are liquid alkaline metals and free fluorine.

PTFE Gasket products are manufactured by taking either pure PTFE or PTFE with other materials mixed in and sintering or extruding it. Sintering is a process where powdered material is held in a mold and then heated to a temperature below the melting point.

There are different styles of PTFE for different application needs and several different styles can be used in the same application. Additionally, PTFE has good electrical insulation, anti-stick, impact resistance and low friction properties. PTFE was first developed by Dupont who still holds the most recognized brand name "Teflon" by DuPont Co. TEFLON® is a registered trademark of E.I. du Pont de Nemours & Co. Your Order Free Quote for PTFE Gaskets : http://gasketsales.com/PTFE-gaskets.php

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Sealing why we need gaskets?

IF it was possible to manufacture flanges to be perfectly smooth and polished, and IF it were possible to maintain these surfaces in permanent contact, then we simply wouldn't need gaskets. Unfortunately this is an impossibility which results from several factors:

! The size of the vessel and/or flanges.

! Difficulty in maintaining these surfaces while handling and installing.

! Corrosion or errosion of the surface over time.

To overcome these factors we use gaskets, which fill these surface imperfections and allow for reliable fluid sealing. In order to get the optimum sealing results from your gasket, these four factors must be considered:

Seating Stress:

You first must provide an adequate sealing pressure in order to seat the gasket so it can fill the imperfections of the flange without destroying the gasket or causing it to extrude. To this end the American Society of Mechanical Engineers, or ASME, has set a minimal initial seating stress guideline in their Pressure Vessel and Boiler Code. ! Sealing Force:

You must ensure that the residual stress on the gasket after seating is adequate enough to make sure the gasket does not separate from the flange. ! Material Selection:

You must make sure that the material you are using is rated for both the pressure it will be opperating under and the fluids that are being contained by the seal.

! Surface Finish: There is a recommended surface finish for every style of gasket and every application. The leading cause of gasket leakage is the incorrect matching of a surface finish to an incompatible gasket material. FAQ for Above Products, Call Phone: (714) 361-1435 & sales@aspseal.com Visit: http://www.aspseal.com

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Three extreme in-house tests for ProTech and competitive Seals

ProTech and Competitive Seals were subjected to three extreme in-house tests with ProTech clearly the seal of choice.
They are,

• 1. Oil Leakage Test
• 2. Water Exclusion Test
• 3. Dust Exclusion Test

1. Oil Leakage Test

ProTech and other seals were subjected to critical oil seal testing using a test machine built to SAE J110 standards. One-hundred hour tests were conducted with severe oil splash.

2. Water Exclusion Test

The test machine was modified by mounting five nozzles at various positions relative to the exterior of the seal to simulate a most severe external hose down. Using water at pressures of 30 to 62 psi, these nozzles individually sprayed each seal from a distance of 3" in both a static mode and while the shaft rotated at various speeds up to 3525 rpm. The nozzles tried to force water past the seal for nearly two hours.

3. Dust Exclusion Test

The test machine was modified with an enclosed chamber containing a large quantity of fine dust and sand which was vigorously agitated with the chamber attached to the outside of each seal area. The equipment operated at speeds up to 3525 rpm for a period of 70 hours in an environment that was literally a dense dust storm. ProTech was the only seal that passed all three torture tests. After lab testing, it was ready to confirm its performance superiority in field trials.

Read More Information about Mechanical Seals click here.

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EPDM Gasket Material

Description: Ethylene Propylene Diene Monomer (EPDM): EPDM is a black plate finish sheet with superior resistance to weathering, ozone and UV exposure. EPDM also provides excellent chemical resistance*, and good electrical properties. EPDM resists animal and vegetable oils, steam, water and oxygenated solvents. This material meets ASTM D-2000-2BA specifications.

High grade material including Mil-specification is available. EPDM is also available in a white FDA approved sheet.

Typical EPDM Specifications: Excellent resistance to UV rays and ozone. Good resistance to Anti-freeze, Synthetic Detergents, Acetone, Boric acid, Ethanol, Formaldehyde, Mercury, Potassium Sulfate, Silver Nitrate, Steam (up to 212 Fahrenheit), Saccharin. For EPDM's gasket materials compatibility with your specific medium please contact American Seal & Packing.

Flexibility: This medium durometer (45-55) sheet rubber offers moderate pliability and elasticity. The harder durometer variant (55-65) offers higher abrasion resistant durability, but less pliability and flexibility.

Applications: Provides outstanding resistance to weathering, ozone and UV exposure. Gasket, bumper and general exterior applications.

Custom Cuts: In addition to hand fabrication, this product can be fabricated using laser, die, and water-jet cut. Please submit your drawings for a price quote. Available in 1/32", 1/16", 1/8", 3/16" and 1/4"

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Spiral Wound Gaskets

Spiral Wound Gaskets :-

Properties And Application :-

Spiral Wound Gaskets are special semi-metallic gaskets of great resilience, there fore they are very suitable for applications featuring heavy operating conditions. Spiral wound gaskets are manufactured by spirally winding a Vshaped metal strip and a strip of non-metallic filler material. The metal strip holds the filler, providing the gasket with mechanical resistance and resilience.
Spiral Wound Gaskets can be reinforced by an outer centering ring and/or inner retaining ring. The outer centering ring controls the compression and holds the gasket centrally within the bolt circle. The inner retaining ring increases the axial rigidity and resilience of the gasket.

Spiral Wound Gaskets should always be in contact with the flange and should not protrude into the pipe or project from the flange. Spiral wound gaskets can be used for sealing flange joints, manhole and handhold covers, tube covers, boilers, heat exchangers, pressure vessels, pumps, compressors and valves; in industries such as petrochemical, pharmaceutical, shipbuilding, and food processing, in power industries and nuclear power stations. They are ideal for steam, oil, liquids, gases, acids, alkalines, various organic mediums and solvents.
ADVANTAGES of Spiral Wound Gaskets

• Sealing under heavy operating conditions.
• Strong stress compensation, stable and reliable sealing performance even
• Under frequent pressure fluctuation condition.
-Solid construction provides stability and seallability even when the sealing surfaces
• Are slightly corroded or bent. - Easy installation.

SHAPE AND CONSTRUCTION OF SPIRAL WOUND GASKETS
Spiral Wound Gaskets are produced in several styles and combination of materials to fit the most stringent application. Spiral wound gaskets are usually of circular shape, however we can produce them in other shapes such as: oval, rectangular, with round corners, etc. Our standard production program comprises a range of spiral wound gaskets with inner diameters of 10 mm to 3000 mm and a nominal thickness of 3.2 mm, 4.5 mm and 6.5 mm. Spiral wound gaskets of non-standard dimensions and shapes, and larger diameters are available on request.

Gasket standard styles: - Gaskets without guide and inner ring - Gaskets without guide and inner ring - Type S - Gaskets with inner ring – ASP-CI - Gaskets with guide (outer) – ASP-CG - Gaskets with guide and with inner – ASP-CGI

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General Service of Metal Bellows

Metal Bellows seals can seal with Flexible Graphite instead of a rubber boot or O-Ring Elastomers allowing it to be used in higher temperature applications. No Springs to clog. Metal Bellows seals are a very effective method of maintaining Mechanical Seal face pressure on the seal face.

Metal Bellows seals that do use O-Rings only require one static o-ring to seal off any leakage along the shaft in Chemical Service this o-ring can be Aflas, EPDM, Nitrle, Viton, Encapsolated PTFE, Ameri-rez, or PTFE.
Because the O-Ring is static it will not wear on the shaft. When installed correctly metal bellows seals will provide exceptionally long service. Metal bellows seals are and excellent solution on chemical applications where Kalrez, Chemrez,Viton, FKM, Buna, Aflas or EPDM are not compatible.
For many years an inexpensive form of metal bellows seals have been used very successfully in the waste water / sewage industry and in the agricultural fields pumping irrigation water. These Mechanical Seals were generally made of a formed bellows rather than a welded bellows. Welded bellows seals are much stronger and have superior flex and recovery characteristics which are more ideal to holding seal faces together but cost more to manufacture. Welded metal bellows seals are less prone to metal fatigue and are available in single and double ply.

General Service of Metal Bellows

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