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A Complete Guide to Rubber Gasket Materials

In our February blog post, we shared five common materials used to make gaskets, which included three types of rubber gasket materials: Silicone, Viton® and Propylene Diene Monomer (EPDM). In this blog post, we will highlight these, and other rubber materials, their applications and their uses as a guide for choosing the right rubber gasket for your next job.

Rubber gasket materials vary in composition and functionality. When choosing a rubber gasket material, several factors need to be considered including temperature range, thickness, system pressure, application, industry and FDA grade to determine the right material for your intended gasket use. While rubber gasket materials may have similar temperature ranges and thicknesses, they are constructed for different applications and purposes.

This guide for rubber gasket materials is meant to highlight important material distinctions to help you make the most informed decision.

EPDM Rubber

EPDM rubber is typically used in hot water and steam conditions. It performs well when used with glycol-based brake fluids and is known for great resistance to ozone, aging and a range of weather conditions. EPDM rubber gaskets offer great resistance to heat, which is why these types of rubber gaskets are used for caustic service and mild acids.

  • Temperature Range: -50° F – +300° F
  • Thickness: 1/16” to ¼”
  • P Max (psi): 150
  • Applications: Water, steam, animal/vegetable oils and oxygenated solvents. Excellent with acid.
  • Typical Industries: Aerospace, construction
  • FDA Approved Compounds: Yes

 Silicone Rubber

You could say that silicone rubber is built for planes, trains and automobiles. Silicone rubber is a versatile material that performs well in low and high temperatures. A silicone rubber gasket prevents oxygen from penetrating and will resist potential problems, like ozone, UV rays and inclement weather. Silicone rubber is used in FDA/food processes, high temperatures and where electrical resistance is needed.

  • Temperature Range: -75° F – +450° F
  • Thickness: 1/32” to ¼”
  • Maximum Pressure (P Max): 150 psi
  • Applications: High temperatures in air or water (excluding oil or steam)
  • Typical Industries: Aerospace, food and beverage and transportation
  • FDA Approved Compounds: Yes

Viton® Rubber

Viton® rubber has a broad range of chemical resistance making it ideal for most applications involving oils, fuels and acids. Viton® rubber boasts excellent resistance to oxidation, ozone and UV exposure. Viton® rubber’s fuel resistance means these gaskets can withstand high-temperature conditions and is widely used for its chemical compatibility.

  • Temperature Range: -20° F – +400° F
  • Thickness: 1/32” to ¼”
  • Maximum Pressure (P Max): 150 psi
  • Applications: Oil/aromatic fuels, mineral, animal and vegetable oils, solvents and hydraulic fluid; Excellent with petrol and lubricating oils, as well as solvents, caustics, acids, etc.
  • Typical Industries: Automotive, food processing and pharmaceutical
  • FDA Approved Compounds: Yes

 Neoprene® (Chloroprene) Rubber

Neoprene® is the most prominent synthetic rubber material. It performs well in low and high temperatures and is commonly used in water, refrigerants, some mineral oils and ammonia applications.

  • Temperature Range: -20° F – +225° F
  • Thickness: 1/32” to 2”
  • Maximum Pressure (P Max): 150 psi
  • Applications: Oil and gasoline, excellent weather resistance
  • Typical Industries: HVAC, automotive and electrical
  • FDA Approved Compounds: Yes

Nitrile (Buna-N, NBR, Acrylonitrile-butadiene) Rubber

Nitrile rubber is used in low and high temperature environments for petroleum-based fluids. This type of rubber is ideal for a majority of mineral oils, some fuels and petroleum-based oils and grease. It is important to note that Nitrile rubber does not match well with glycol-based brake fluid, phosphate-ester fluids and high aromatic content fuels.

  • Temperature Range: -25° F – +212° F
  • Thickness: 1/32” to 2”
  • Maximum Pressure (P Max): 150 psi
  • Applications: Oil/aromatic fuels, mineral, animal and vegetable oils, solvents and hydraulic fluid
  • Typical Industries: Military vehicles, mobile equipment, white FDA, general service and utility
  • FDA Approved Compounds: Yes

SBR (Styrene-Butadiene) Rubber

SBR rubber is the oldest synthetic rubber material and is durable and resilient. The most popular form of SBR rubber used to make gaskets is called “Red Rubber,” named for its reddish-brown color. SBR rubber performs well in low and high temperatures and is typically used in a range of wastewater and many other utility applications.

  • Temperature Range: -40° F – +180° F
  • Thickness: 1/32” to ¼”
  • Maximum Pressure (P Max): 150 psi
  • Applications: Air and hot and cold water; excellent abrasion and impact resistance, and resilience
  • Typical Industries: Interior plumbing and drainage systems
  • FDA Approved Compounds: Not typically used in food applications, however some specialized food-grade versions (white SBR) have been developed

There are many impactful characteristics and features to consider for your intended gasket purpose. When choosing a gasket material, the main objective is to pick one that will seal the deal. Let this blog post be your guide for making that decision.

To learn more about gasket materials, contact Expert Gasket & Seal today at (330) 468-0066.

 

Five Gasket Materials That Will Seal the Deal

There are a variety of materials that can be used to make gaskets. When preventing leaks is the objective, it’s very important for these materials to be reliable and long lasting. But before determining the right material for your project, you must first consider how your gasket will be used. Here are some things to think about before deciding what material to use:

  • What application will the gasket be used in?
  • What temperature range will the gasket be used in?
  • Are there any potential chemicals that may come in contact with the gasket?
  • What type of system pressure will the gasket need to endure?

Once you have determined the use for your gasket, the next step is figuring out the type of material that will best serve this purpose.

There are many types of materials we use at Expert Gasket & Seal to make gaskets. Here are a few popular materials to consider for your next project.

Rubber Gasket Materials

  • Silicone rubber is a versatile material that is effective in high and low temperature environments. A silicone rubber gasket will prevent oxygen from penetrating as well as resist a lot of potential problems, like ozone, UV rays and inclement weather.
  • Viton rubber has an exceptionally broad range of chemical resistance making Viton a perfect option for most applications involving oils, fuels, acids, this material boast excellent resistance to oxidation, ozone, and UV exposure.
  • Propylene Diene Monomer (EPDM) rubber is used in hot water and steam conditions. EPDM rubber is also used with glycol-based brake fluids and is known for great resistance to ozone, aging and a range of weather conditions.

For compressed gasket materials, here are a couple of frequently used materials in this gasket category.

Durlon Gaskets

  • Durlon® 8500 is a green colored NBR binder/Aramid-Inorganic fiber compressed sheet. This would be a great choice for steam, natural gas and a number of petroleum-based fluids. It will perform in temperatures as low as -100 degrees Fahrenheit and as high as 700 degrees Fahrenheit. The continuous max temperature is 548 degrees Fahrenheit.
  • Durlon® 8400 is a gold colored NBR binder/Phenolic fiber sheet. This type of material is a popular choice when a wide pH range is needed. It’s an excellent choice in chemical, pulp and paper and other industrial applications. This material will perform in temperatures as low as -100 degrees Fahrenheit and as high as 800 degrees Fahrenheit. The continuous max temperature is 554 degrees Fahrenheit.
  • Durlon 9000 is extensively used in chemical, pulp and paper, food and beverage, and the railroad tanker industry.

There are many considerations to make when determining which material to use to make a gasket. Once you settle on the type of material you need, Expert Gasket & Seal’s sealing professionals will provide you with the precise gasket you need from our state-of-the-art facility using a traditional die-cutting process or a computer-controlled, die-less, Flashcut process.

To learn more about gasket materials, contact Expert Gasket & Seal today at (330) 468-0066.

Is CAD Needed to Prototype Custom Gaskets, Seals and Other Parts?

Traditional manual gasket production requires creating templates or steel dies, doubling the time to manufacture the gasket. When gasket designs are computerized and run through CAD software, small alterations to gasket designs take much less time and do not require dies or re-tooling, making them ideal for prototyping and perfecting your design before mass production. For prototyping purposes, having CAD designs ready to go for the parts you need is ideal. But what if you dont have a CAD file or drawing to start with?

Maybe you have a product sample and need to prototype two-dimensional gasket from the sample, or maybe you created a gasket manually, without a CAD file, that you need to duplicate. Expert Gasket has a solution that is both fast and accurate at replicating products without design files.

Gasket Prototyping Without CAD Files Via Optical Scanning

Along with our Flashcut technology, we utilize a high-tech optical scanner that allows us to make a 3D scan of the product or component sample and build a computerized model (CAD file) from the physical sample.

This scanner enables you to capture your object’s shape and geometrics quickly and accurately through millions of XYZ data points and provides thorough measurement data of the entire surface of your object, creating a complete digital representation of your part and verifying that the part matches your CAD model.

Once your CAD model is complete, your prototype can be created with our die-less Flashcut system. This entire process allows for fast, accurate results while shortening your time to market and reducing labor and material costs.

Rapid Gasket Scanning and Prototyping for Any Application

Expert Gasket & Seal provides cost-effective, rapid prototyping for most flat gasket non-metallic applications. Our Flashcut machinery’s computer-controlled, high-speed knife cutting system produces precise, close tolerance parts on soft materials. This allows us to design and quickly prototype custom gaskets made from rubber, cork, PTFE, compressed non-asbestos and many other materials.

This cutting-edge technology fabricates accurate gaskets and other products from your CAD file or from your original .pdf drawing, and it is die-less, so there is no need to tool new dies for each new design – plus, it’s simple to reconfigure new settings, so you get a finished product faster.

To learn more about Prototyping, with or without a CAD file, contact Expert Gasket & Seal today at (330) 468-0066!

What Are Mechanical Seals?

Mechanical seals are seals are typically used on rotating equipment such as pumps, compressors, and mixers. They keep potentially hazardous gas and fluids that are being processed from contaminating the environment. Keeping these materials away from plant personal and vulnerable equipment. devices that form a barrier around moving parts to prevent contamination from the outside, and to keep components within the device from leaking.

Common Types of Mechanical Seals

Cartridge Seals

Single Cartridge Seals are seals that are factory assembled so they avoid any field installation issues. They are preassembled components composed of a gland, sleeve, faces, and springs. All the components are factory pressure tested and have pre-set spring tension. These are basically bolt on seal.utilize two flat surfaces that slide against each other and are held together by a spring. They are pre-constructed and ready to use, which minimizes installation and maintenance.

Double Cartridge Seals are seals similar to single cartridge seals, but use two separate seals positioned next to each other to reduce or eliminate any leakage of fluid from the interior of the device chamber. Double cartridge seals are also ready-made to be used with minimal installation and maintenance effort. These seals maintain the lowest leak rates possible for fugitive emissions, environmental contamination and safety to plant personal.

Component Seals

Single Spring mechanical Seals utilize two separate components that are field assembled. The spring & face rotate together and run against a stationary seat to seal off process fluids. The single spring provides the load or pressure that holds these faces together.

Multiple Spring Mechanical Seals are built in the same way that single spring seals are built with the exception that they utilize multiple springs to ensure uniform distribution of force to keep the seal shut. This helps to reduce leaks and wear and tear on the seal.
Non-Metallic Cartridge Seals are similar to single cartridge seals with the exception that they do not use metallic components. These are often used when the fluids being sealed off would cause corrosion or damage to the mechanical seal.

Related Seals

Bearing Isolator Seals are seals designed specifically to prevent external contaminants from damaging bearings, and to keep bearing lubrication from leaking out of the bearing.

How Are Mechanical Seals Used?

Mechanical seals are typically used on pumps of all different varieties. Pumps typically need to seal off fluid contained within the pump while also allowing motion to be transferred away from the sealed chamber. This usually involves a rotating shaft. The problem is that this opens up potential for fluid to leak where the shaft connects from the exterior of the pump to the interior chamber. Mechanical seals help to prevent these leaks and seal the fluid inside the chamber without hindering the moving components’ motion.

Mechanical seals are used across an enormous range of industries and applications. Any industry that involves moving fluids will likely use pumps that require mechanical seals, and many other industries also regularly use mechanical seals.

Industries that use mechanical seals would include:

  • The Oil Industry
  • Chemical Industry
  • Food and Beverage Processing
  • Utilities and Wastewater Processing
  • And many more

To learn more about our mechanical seal offerings, contact Expert Gasket today at (330) 468-0066!

How to Choose Rubber Gasket Thickness

When choosing the gasket thickness for compressed materials,  remember that thinner is better.  Most compressed sheet gasketing sealing values are based on 1/16” thickness.  Thicker materials require a greater compressive force to seal and have lower pressure ratings. The use of 1/16” thick gaskets will provide better sealing with lower bolt loading than 1/8” thick gaskets.  Thinner is better! 

Do you know your Viton®?

Many rubber materials claim to be Viton®, but are generic fluoroelastomers, or blends of other compounds with some Viton®. Blends generally have lower fluorine content and will not withstand exposure to many fluids and elevated temperatures the same way as genuine Viton®. All of the Viton® gaskets and sheet goods we provide are 100% Chemours Viton®. Count on Expert Gasket & Seal to provide the proper grade of genuine Viton® for your severe sealing application.

Durlon 9000 vs Virgin Teflon®?

Durlon 9000 will seal better than Virgin Teflon® (PTFE) in typical flange gasket service.  This is due to its construction, combining inorganic fillers with pure PTFE resins.  The result is a PTFE material that does not cold flow, yet retains the inert properties of Virgin PTFE.

Durlon 9000 is also easier to fabricate than Virgin PTFE, can be factory welded into large single piece gaskets, and is excellent for chemical, FDA, and pharmaceutical environments.

Please ask us about improving your Virgin PTFE application using Durlon 9000.

Spiral Wound Gaskets Color Codes

Spiral wound metallic gaskets used on standard ANSI pipe flanges are color coded on the OD edge to identify their winding & filler materials.  The most common is a yellow painted edge with a pink stripe.  This signifies a 304 stainless steel winding and Mica-Graphite filler.

Another common winding is 316 stainless steel with a flexible graphite filler.  Its color code is a green painted edge with a gray stripe.  There are many others spiral wound gasket color codes.   Please contact us for a color code chart that identifies the various combinations.

Rubber Hardness for Rubber Gaskets, Seals & O-Rings

Rubber hardness is expressed on the Shore A scale, and is measured with a durometer. The number may be specified as “60 Shore A”, or commonly as “60 durometer”. The number, itself, signifies the relative hardness within the A scale. Typically, the hardness of calendered rubber sheet ranges from 40A (soft) to 90A (very hard) in 10 point increments. Hardnesses below 40A are also available, though these sheets might be molded rather than calendered.

The most common rubber gasket hardness for Neoprene, Nitrile, and EPDM compounds fabricated from sheet is 60A, though softer and harder grades are also available. Red SBR (red rubber) is generally 75-80A, and Viton is typically 75A. Molded rubber products are available in hardnesses from 20A to 90A. O-ring hardness is usually 70A and, as with all rubber products, options are available.

All hardnesses have a tolerance of +/- 5 points. This means a 70A rubber can measure 65A, and a 60A rubber can also measure 65A; both would be acceptable. Because of the tolerance, it might be advisable to consider at least 20 point changes when testing the effect of particular hardnesses.

Please contact Expert Gasket & Seal with questions regarding rubber hardness for your rubber gasket, rubber seals, or rubber o-ring applications.

FDA Rubber Gaskets

FDA rubber gaskets are fabricated from rubber sheet that is made from FDA approved ingredients in compliance with Title 21CFR177.2600.  The gaskets, and the sheet from which they are made are not FDA approved – it is the ingredients used to produce the sheet that meet the requirements of Title CFR177.2600.  This regulation for rubber materials includes many compounds, such as Nitrile, Neoprene, Viton, Silicone, and others.  FDA gaskets are required in applications where the gasket comes in contact with food products.

Expert Gasket & Seal stocks FDA Nitrile & FDA Silicone in several thicknesses and can provide FDA rubber gaskets from other compounds as well.  Expert Gasket & Seal also provides non-rubber FDA gaskets from Teflon® and PTFE based materials such as Durlon 9000 & Durlon 9600.  Please contact us for assistance with your FDA application.