elastomeric seals
- January 20, 2023
Tech Bulletin: How to Read an ASTM D2000 Standard Callout
Here at Gallagher, our engineering team loves to help customers with their technical and application challenges.
If you are new to the sealing industry, returning after a hiatus, or just haven't needed to be in-the-know with ASTM D2000, it can be a confusing concept. That's why we put together this handy 2-page tech bulletin to give you everything you need to know about how to interpret your own ASTM D2000 callout.
This short bulletin will discuss:
- Measurement Units
- Grade Number
- Type and
- August 31, 2022
A common question that comes from many customers is: “Can you tell me which O-ring compound meets this ASTM D2000 callout?” It’s understandable, since at first glance, the ASTM D2000 callout can be intimidating for determining the type of O-ring material. However, the ASTM D2000 is a very useful tool to quickly specify requirements for O-ring materials, and is standardized so it is easy to interpret industry wide. So, what is the ASTM D2000 specification, and how can I interpret it?
What is ASTM D2000?
ASTM D2000 is a standardized description of rubber compounds. It was first developed for use in the automotive industry, however it is now used by many industries to specify requirements for rubber compounds in a consistent way. Think of the specification as a common language everyone in the rubber industry speaks, allowing us to communicate easily with each other without an interpreter. An ASTM D2000 callout
- August 19, 2022
VICTREX CT™ 200
VICTREX CT™ 200 is a High-performance thermoplastic PEEK polymer suitable for dynamic sealing applications at very low temperatures.
As the latest member of the VICTREX CT™ PEEK polymers, the 200 grade series exhibits improved sealing over a wider range of temperatures, compared to commonly used materials such as PCTFE. It does so at low temperatures on account of its greater ductility, and at high temperatures due to its superior creep resistance. It also offers a lower static and dynamic coefficient of friction which helps minimize torque and wear, allowing smaller actuators and saving space and weight.
In addition, laboratory testing indicates that they may require less torque to actuate since they have a lower static and dynamic coefficient of friction compared to PCTFE. This results in less wear, higher performance and a potential for cost savings.
VICTREX CT™ 200 can replace Kel F PCTFE in
- May 06, 2022
More often than not, the process of parts material selection and/or development can get fairly involved. To summarize: it’s similar to a game of pros vs cons where so many different variables come into play. In the case of TPE, the principle is no different. Factors such as meeting the performance requirements for a specific application, economic assessments, and processing issues, should all be reviewed in order to make the optimal choice. Looking at the qualities and considerations of this material can get this quest for the best off to a great start.
What is TPE?
Thermoplastic Elastomers, or TPEs, are flexible materials that exhibit the properties of rubber, but are processed like plastics. When they first became available commercially in the 90’s, it was a whole new exciting development for the realm of engineering. TPE’s growth rate escalated as these high-performance materials continued to be used in a plethora of applications.
- March 23, 2022
Natural Rubber Short Supply
Plagued by global supply chain issues stemming from coronavirus and environmental issues, the natural rubber shortage continues to be exasperated by the war in Ukraine and Russia.
In 2021, shortages were reported mainly due to flooding and leaf disease. A poor crop led to a decrease in the cultivation of these highly desirable trees. The supply for raw gum already was expected to remain tight for several years due to the 7-year maturity period for the trees, but the unfavorable seasonal crop significantly affected the availability of rubber.
This blog article will also dive into the short supply of carbon black and its affect on the rubber availablity on a global scale.
- April 28, 2021
In the Oil & Gas industry, the need for elastomers to seal higher pressures for sustained periods of time with minimal damage is abounding. Applications such as drilling tools, completions equipment, blow out preventers, and subsea pressure control systems now routinely require or exceed 15,000 psi with both liquid and gas media for functional testing and qualification. Parker meets this challenge, providing a best-in-class extrusion and rapid gas decompression resistant hydrogenated nitrile (HNBR) compound called KB292.
One of the most common failure modes for seals utilized in high pressure applications is known as extrusion or nibbling. This failure method emerges when the seal material is forced into a clearance gap that is present between the mating substrates and gradually can be cut, nicked, or chewed away.
- April 13, 2021
Have you been frustrated with going through multiple design iterations when rubber components are failing due to high stresses or your device has been leaking due to insufficient compression? Have you lost months and months of precious time having to recut tools and make design changes?
FEA takes out the guesswork
Finite element analysis, also known as FEA, is an effective tool used in design iterations. It allows for different design ideas, options, and alterations to be quickly, effectively, and precisely compared.
Using FEA can improve both the speed and quality of product design as well as reduce the overall cost. Rubber parts, such as silicone diaphragms, septums, seals, valves, tubing, and balloons are critical components in today’s medical devices that can benefit from the use of FEA.
- February 12, 2021
The manufacturing and installation of specialty seals must be handled in a certain way to ensure their quality and longevity.
The following guidelines and/or rules are the basics for regulating the engineering of seals to ensure top performance.
Performance vs Knowing Your Seals
The performance of your machine(s) depend on the quality of your seal and the conditions they succeed in. They can directly affect how well or how poorly your machines function. By extending the life and care of your seals, you can, in turn, extend the life of your equipment.
- April 15, 2020
Article re-posted with permission from Parker Hannifin Sealing & Shielding Team.
Original content can be found on Parker’s Website and was written by Jarrod Cohen, marketing communications manager, Chomerics Divison.
Electrically conductive elastomers are elastomeric polymers filled with metal particles. They can be grouped by filler type and elastomer type. Then within each of these classes, there are standard materials and specialty materials.
Parker Chomerics manufacturers electrically conductive elastomers in gasket form, also known as EMI elastomer gaskets, under the CHO-SEAL brand. We won't get so much into gasket configurations and dimensions here, we'll just stick to classes of materials. So what is available? Let’s find out.
Conductive elastomers are metallic particle filled elastomeric polymers, the particles giving the shielding performance and the polymer making them “rubber." There are many materials within this generic material type, but we'll focus on the below.
Particle fillers
Setting up the grades of conductive elastomers by filler types involves six different particles:
Three types of elastomer material
- Silicone
A polymer that has a large temperature range especially on the low end down to -55F. It is a very soft material with a low compression set. - Fluorosilicone
Close to silicone, but will not swell and degrade when exposed to solvents, fuels hydraulic fluids and other organic fluids. Although slightly harder than silicone, it is still relatively soft with low compression set properties. - Ethylene propylene diene monomer (EPDM)
Does not have the temperature range nor the softness of silicone, but is resistant to highly chlorinated solvents used for compliance with NBC decontamination and is only used for applications with those needs.
All of these materials are cured or cross linked when the gasket is made. The cure either happens with heat or atmospheric moisture.
- Silicone
- February 07, 2020
The term “plastics” is generic way of describing a synthetic material made from a wide range of organic polymers. Organic polymers describes a man-made substance that is formulated using polymer chains to create what we commonly refer to as…(you guessed it), plastics.
Before plastic, leather had been used to create Backup ring devices behind O-rings. Leather allows fluids to be retained, providing lubrication for the O-ring when the system was running dry.
The problem with leather was that it could become dry and shrink away from the sealing service, exposing the elastomer to same pressure it was intended to protect against.
With the advent of polymers, a piece of plastic could be cut or formed into the exact shape to allow for zero extrusion gap, and for continued protection for the O-ring.
Some polymers were very brittle. Since they needed to be deformed to allow for installation into solid glands, the cut of the plastic could nibble at the O-ring, causing premature failure of the element it was supposed to be protecting.
The Revolution of PTFE
When PTFE moved out of the lab and into industrial use, it quickly found itself adjacent to the O-ring. PTFE offers extrusion resistance and, at the same time, doesn’t erode or nibble at the O-ring due to the “softness” of the polymer.(Hardness between 55 and 65 Shore D)
Given the composition of PTFE, or Teflon, it could be utilized as a sealing element to protect Backup rings and conform to the shaft. The bonus was it was generally easy on shafts (depending on the filler added to the PTFE).
There are some negative aspects to Teflon that needed to be overcome by early engineers. First, it has a fairly high rate of Thermal expansion which, by its own nature, could often times lose contact with the sealing surface. This meant some kind of loading was necessary to ensure contact.
PTFE is as tough as other polymers, so the fact that it could seal on a shaft made it vulnerable during installation for tears or nicks on sealing surface.
Second, if it were stretched during installation, the material had to be sized back to its original shape due to its poor elastic properties.