What are the different styles of PTFE

Molded and Sintered PTFE:

This type of PTFE was the first to be introduced to the market. This style is made from virgin or reprocessed PTFE resin, without fillers, which is then molded, compressed and sintered. As with any other type of plastic, PTFE has a high creep factor when compressed. The creep factor is detrimental and can lead to having to re-tighten the bolts to maintain seating pressure and prevent leakage. The higher the temperature in the application it is used for, the more the creep factor will increase. Even with these drawbacks, PTFE is affordable, easily available and highly chemical resistant.

Skived PTFE:

This style is similar to molded and sintered PTFE as it is also make of virgin or reprocessed PTFE without fillers. Instead of molding an individual sheet, the sheets are taken from a billet of PTFE with a process called skiving. The skiving process was developed to overcome manufacturing deficiencies of the molding process. Skived PTFE shares the same creep characteristics as molded and sintered PTFE.

Molded or Skived Filled PTFE:

In order to correct the creep characteristics of molded and skived PTFE, manufacturers started adding mineral fillers or fibers in order to reduce creep factor. This indeed reduced the creep characteristics but not by a significant amount.

Restructured Filled PTFE:

Besause the addition of fillers in the molding process was not enough to significantly reduce creep, a new manufacturing process was developed to produce filled PTFE sheets. In this new process the material is laminated before being sintered, which yeilds a highly fibrillated structure with significantly less creep. The different fillers used in this process are as follow:

• Barite: Added for use in strong caustic service. Also FDA compliant.

• Mineral Silica: Used for strong acidic service.

• Hollow Glass Microshperes: Used to increase compressibility.

• Synthetic Silica: Used as subsitute for glass microspheres.

Expanded PTFE:

This style of PTFE is made by heating and stretching PTFE before sintering it. Lke all PTFE it has strong chemical resistance, but unlike molded or skived PTFE, this material has a high compressibility and is good for use in flanges made from fragile materials. The only drawback to this material is that its floppy and difficult to install, especially if the flanges cannot be separated.

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Types of Cartridge Seal

Single Cartridge Seal

A versatile single seal for use in a wide variety of applications.

• Stationary Seal
• Self-Centering Lock Ring
• Adjustable gland tabs
• Monolithic Seal Faces
• Low heat generation
• Non fretting pump/seal parts
• 360 degree flush port orientation
• Low emissions design

Buy online : http://www.sealsales.com/MScart1.shtml Double Cartridge Seal Double Cartridge Seal is a general duty, dual seal for plant wide use.

• Geometric Double Balance
• Self-Centering Lock Ring
• Unified Seal Face Alignment
• Internal Pumping System
• Floating flow channel
• Springs isolated from fluids
• Large barrier fluid ports
• Monolithic Seal Faces

Buy Online : http://www.sealsales.com/mechanicalseals/Doublecartridge.shtml

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Why Mechanical Seals ?

One of the most important advantages of the mechanical seal is its low leakage rate, resulting in a cost saving because of the reduxtion in lost liquid.
The hazards of fire and personal injury are also reduced when the pumps are handling inflammable or toxic products. Simplified pump designs and reduced maintenance costs are also plus factors.

Mechanical Seals Online Shopping in USA by mechanical-seal The Most Common Seal Consists of a stationary flat seat which is mounted into a gland or seal chamber, a spring loaded rotating face and a static seal along the shaft. The spring holds the rotating face to the stationary face and sealing occurs between the parallel faces. The static seals stop leakage between the shaft and the rotating seak head and also behind the stationary seat. The faces of the Mechanical Seal in operation do not actually rub against each other, but are separated by a thin lubricating film a few molecules thick. This can account for the slight weepage from some seals that are operating satisfactorily.

Since all the wear is on the seal faces, further savings are realized due to elimination of shaft or sleeve wear which would result in use of packing.
Most Seal applications will runs years with little or no maintenance. Time formerly spent on adjustment of packing can be used elsewhere.

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Rubber Molding

Ever look at a molded rubber part and ask yourself “how do they make that”? Those of us that had toys that would surely be ruled as unsafe for children today, just might have had a small rubber molder.

The advantages of being able to create worms, spiders, and cockroaches that looked, real but did not hurt when your older sister threw it at you...was priceless. I had no idea at the time, but it served a my introduction to the rubber industry. I’m sure I used that machine until I ran out of the included silicone compound, or until I burned myself one to many times.

I did not know it at the time, but my process for making worms and spiders was compression molding. My spiders were made using what amounted to a hot plate, with attachable molds. Select your mold, add enough compound to fill the mold with minimal excess (see flashing). Close the lid and turn on the hot plate. After waiting the prescribed amount of time, turn off the heat & let the mold cool. If your impatient like me, this is where you burn your fingers. Once cool, open and gently remove the spider from the mold, being careful not to remove it too quickly and tear the legs off, or leave legs in the mold (which will ruin the next spider).

Today I’m out of the spider making business. But having that childhood experience helped me to understand what was happening the first time I stood in front of a multi-mold compression press producing thousands of parts for the oil industry.

Now at American Seal & Packing, we can offer custom made shapes, from o-rings to golf grips and well head components utilizing Compression Molding, Transfer Molding or Injection Molding. Each method has it’s own advantage.

Compression Molding is the ideal method for medium-sized and large items produced in small to medium batches. It is also the best method for expensive rubber types such as Viton® and Aflas®, FFKM, and applications which require extreme rubber hardness.

Advantages:
Low mold production costs

Short tooling times

Helps in the processing of rubber types which are difficult to work with Excellent for products with high density and therefore long process times

Transfer Molding - combines the advantages of injection molding with the practicalities of compression molding.

Advantages:

Perfect for items with complex design

Provides short lead times

Allows narrower dimensional tolerances than compression molding

High uniformity with little flash

Quick tooling

Suitable for micro-components (like injection molding)

Injection Molding Rubber injection molding is the ideal method for the mass production of small or medium-sized items, complex inserts, items with narrow dimensional tolerances and components which require high uniformity. Liquid Silicone Rubber molding is another injection method we can offer. Similar to rubber injection molding, it offers the advantage of speed for high volume production. Advantages:

Short molding process

Low unit cost

Narrow cross sectional dimensional tolerance

Minimal flash

Minimal waste

So, if your in need of high volume parts, low volume with low tooling costs, or small parts with high detail, we have the best method available to produce your parts.

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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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