Webinar: Extreme Low Temperature Elastomers and Custom Sealing

Parker Webinar Extreme Low Temperature Sealing.mp4 - powered by Happy Scribe

Welcome to Parker's webinar on extreme low temperature resistance in elastomers. My name is Samantha Sexton and I'm the marketing communications manager at Parker O-ring and Engineered Seals Division.

Before we get started, I'd like to point out a few housekeeping items. All participants will be placed on mute during the webinar. Please take a moment to check your audio settings and ensure you are in listen only mode. We will have a Q&A session at the end. So if you have questions during the webinar, please submit these via the Q&A feature in your Zoom panel. Also, this webinar will be recorded. A recording will be available at www.parker.com/OES under the Solutions tab. We will also send you a link to the recording via email. And lastly, there will be a short survey at the end of the webinar. Please take time to fill this out so that we can bring you future topics of interest. And now I'll hand the discussion over to our speakers. Tyler Karnes and Max Miller. Max.

Hi, everybody. I'm Max Miller, currently, part of Parker EMG's aerospace and defense sales team covering the Northeast region. Prior to my current role, I was a market manager at Parker CSS's North Haven facility, also known as the Advanced Products Business Unit. There, I covered the metal seal product line, providing commercial and application support for various industries.

And my name is Tyler Karnes. Just like Max, you know, I'm also one of the aerospace and military sales engineers of Parker EMG covering the southeast United States. Before that, I had roles in our OES Division as a business development engineer for aerospace and military. And then before that was also with the applications engineering team.

So for many of you all who may know Parker, this is probably just a recap of some information for you guys. But Parker is one of the global leaders in the motion control industry. We have hundreds of thousands of customers. We have facilities on many continents around the globe servicing, you know, like I said, hundreds of thousands of individuals. And again, as a $14 billion company that puts us around in the Fortune 200 range. So, you know, we're an industry and a company that understands various markets, various industries and how to solve needs with a personal focus on our customers.

Diving into specifically what we're going to talk about in this presentation is, again, the extreme low temperature sealing options we have with our Engineered Materials Group.

We're going to start off talking about some elastomeric polymers and compare those in the low temperature performance that those materials offer. And then we'll jump over and Max will share from our CSS Division some other low temperature options within the metal seals and other types of sealing solutions as well. He'll give some real life examples, and again, we'll finish off with some dynamic sealing. And then we should have some time at the end for a summary. And then question and answers that you guys can submit during this presentation.

So as I mentioned, we're going to start it off with our O-ring and Engineered Seals Division material family, specifically elastomeric polymers.

I always like to start off with this slide as it gives a really good visual representation of all of the different types of polymers that we have to offer. And you can see on the vertical axis there shows the temperature range, relatively, for each of these materials. We're going to focus within this first part of the presentation, specifically on the VMQ or silicones, our FFKM offering that's pushing the boundaries of lower temperature. And our FKM offering that's also pushing the lower boundaries of what those materials are capable of.

Before we get into specific materials, it's always good to understand exactly how we measure a low temperature capability with elastomers. So in a minute, you're going to see this picture animate in front of you and show the test that we do to determine this. It's called the TR 10 test.

That black sample you have in there is what we call a dog bone shape cutout of an elastomer material. And what we do is we elongate it, as you'll see here, 50 percent beyond its initial length. And then we'll cool that solution down to a very cold temperature. We'll release that sample and slowly warm that solution back up to where that sample is going to retract back to its original length. When it retracts 10 percent, that temperature recorded the temperature of the solution is in recorded, and that's called the TR 10 temperature-- the temperature at which that sample has retracted 10 percent.

In this instance, you can see the TR 10 is about minus 45 degrees Fahrenheit. Industry standard tells us that elastomers can perform in static low temperature environments about 10 degrees Fahrenheit below their recorded temperature. So in this case, the low temperature capability of this material would be about minus 55 Fahrenheit. Again, we use this as a very objective way to determine what the low temperature capabilities of elastomers are.

So again, jumping into some specific materials that we want to highlight as being really what has pushed the boundaries of technologies in this extreme low temperature environments. On our FFKM or perfluoro-elastomer side, our FF400 is best in class in terms of low temperature capability within that material family. Having a low temperature range of minus 40, this materials commonly used in our oil and gas markets. As you can see, it also has ISO Total and other RGD and sour service certifications. It's also gotten a lot of traction within the chemical processing, and we've even had some inquiries for it in aerospace, where they continue to need to push the boundaries both on a low temperature performance and a high temperature performance side.

Some of you may know FFKM's are excellent on high temperature resistance and chemical resistance, but their big drawback has been not as great low temp performance compared to other materials. However, the FF400 pushes that boundary down to a minus 40 Fahrenheit.

Looking at some specific data, as you can see while we have a very strong, low temperature performance of a TR 10, we also have strong high temperature performance, as you can see with the compression set data there. So even after 70 hours at 250 Celsius, which is about 500 Fahrenheit, still only about a 30 percent compression set. So strong high temp performance, as well as having a strong low temp performance. You're not giving up anything on the high side to get that great performance on the low side.

In our FKM's the material that really pushes that boundary is the VX065. This is one we've had out for a little bit, but continues to be best in class on low temp resistance for FKM services. Additionally, there's an AMS spec for military and aerospace service that's written with the VX065 in mind. AMS7410 defines how these low temperature FKM materials should perform and VX065 has already passed certification testing for that spec. In addition to having great low temp service, we still have excellent compression set and excellent fuel and turbine oil resistance as well.

Within the aerospace industry. For many years, companies had to kind of make a compromise. They would either put FVMQ or fluorosilicone materials which, as you can see, have a really great low temperature performance minus 105 Fahrenheit. But the compression set even at 400 Fahrenheit wasn't as great. Or they could put a GLT FKM, which before that was sort of the benchmark for low temperature performance for fluorocarbons, which had great compression set compared to the fluorosilicone, but didn't really get to the lower limits that the industry needed. With the VX065, as you can see, it has the best in class compression set compared to either of those materials and the minus 65 Fahrenheit low temperature limit, which is really what the industry needs for those high atmosphere commercial aircraft or other low temperature services needed.

In addition to having these low temperature tests completed, we also did some extreme high temperature testing with this material. So the VX065 was tested all the way up to 570 Fahrenheit and still only had a 60 percent compression set, which is very good for an FKM material at that high, aggressive temperature. So we've expanded the high temperature compression set capabilities while also having best in class low temperature with the VX065.

Very similar to the VX065 is really what we'd like to call its sister compound, the VX365. This material has very similar properties, similarly in the low temperature and compression set range. The only difference is this is a 90 durometer material. So you have all the same properties, but with an increased pressure rating and hardness. This is a material that's commonly used in the oil and gas industry. As you can see, we've got the RGD and our service ISO certifications for this material as well. And again, you get all of the great properties of VX065 just within 90 durometer increase pressure rating.

And the final elastomer that I'll talk to you guys about today is our S0383. We like to call this the deep space silicone. Having a temperature range down to negative 175 Fahrenheit, it's the lowest an elastomer can go that Parker offers for cold service that can handle those extreme deep space cold applications. In addition, similar to like other silicones, you get great compression set properties on the high side as well, but you get this extreme low service.

An interesting anecdote about this material: When we went to tested to see how low that the low temperature could perform, we really maxed out the capability of our cold temperature machine. So it was still flexible at that extremely low negative 175 Fahrenheit benchmark. But that was as low as the testing equipment could go. So we weren't able to to fully max out and demonstrate what this material could do. But in any case, you still get that great low temp performance. And as you can see here, compression set 300 degrees Fahrenheit 70 hours, still, only 15 percent taken.

The typical applications we recommend for that, as I've mentioned, is those outer space applications. But we also have it certified to the various AMS and MIL specs as well in case that is needed for those services as well.

So that concludes what we'll talk about in terms of our elastomer offerings. I'm going to throw it over to Max, who will tell you a little bit more about what Parker CIUSSS and other divisions within EMG have to offer in the way of low temperature service.

Hey, everybody, in the next few slides, I'm going to discuss using metal seals in low temperature applications and conclude with a quick summary of Parker's dynamic sealing options.

So to begin, it's best to understand the basic question of what is a metal seal? A metal seal is an engineered device that can be made from various metal alloys designed to connect two pieces of hardware while minimizing or preventing leakage. A main advantage of a metal seal over other metallic based seals is that they are resilient, meaning they're able to recover after being compressed.

Parker offers their metal seals in a variety of cross-sections, as shown below, which provide varying levels of sealing load and leak performance. These provide the same function as an elastomer seal, but metal seals are chosen on application for an elastomer sale just won't cut it.

The most common reason for selecting a metal seal over an elastomer seal is temperature. Tyler presented this chart earlier, showing the temperature capabilities of various elastomer seals. Here we added a block to show Inconel 718's capability. In reality, this only shows a limited range of Inconel 718's capability. We recommend it for use up to 1250 degrees Fahrenheit on the upper range and on the lower range, it s recommended for use down to near absolute zero. 718 is a suitable material at these low temperatures because it is able to maintain its strength and ductility, whereas various other alloys can become brittle, which can weaken a seal.

A metal seal's advantage doesn't stop at their extreme temperature capabilities. In addition, metal seals can be used in applications with extreme pressures -- from vacuum applications to pressures of well above 50,000 psi. In some cases, high pressures can even improve the sealing ability due to a phenomenon we call pressure energization. Explosive decompression, UV and ozone degradation and permeation are not a concern in using metal seals. They also offer excellent chemical resistance. Lastly, metal seals have the potential to offer ultra low leak rates. Some cross-sections will seal helium to leak rates as low as 10 to the negative 11 cc's per second. That is equivalent to 1cc of leakage every 3000 years.

Metal seals can be extremely useful in certain applications, but there are some strict requirements and limitations that need to be kept in mind if planning on using these seals. Metal seals are only suitable for static applications. Parker doesn't have any metal seals suitable for dynamic applications. Compared to elastomer seals, metal seals require much higher loads to compress the seal. Compression loads are dependent on which cross section you choose, but some cross-sections will require thousands of pounds force per inch circumference.

It is extremely important to take this into consideration, as it will require your hardware to be sturdy enough to handle these loads. And the mating surfaces will have strict requirements of surface hardness. A good surface finish typically of 32 micro-inch Ra or better is recommended as metal seals are unable to conform to the surface imperfections due to their base materials' hardness.

As already touched upon, metal and elastomer seals are often used in similar applications. It's important to understand when to use one over the other. A quick recap on the advantages of metal seals are as follows. A metal seal is able to function at extreme temperatures and pressure while offering resistance to a wider range of fluids and chemicals. This combination is important to note. For example, Tyler noted, the extreme low temperature capability of the silicone compound S0383-70. It's true that you can use this compound at negative 175 Fahrenheit in some applications. However, if you're looking to seal any aggressive chemistries, you may run into issues and be forced to use a metal seal. Other requirements that may force you to use metal seal over an elastomer are extended fire resistance and needs of extreme lifespan.

To close the metal sales, I'd like to give you a few low temperature applications for Praker metal seals relating to the aerospace industry. The first example relates to rocket propulsion systems. Specifically, PTFE-coated metal C-Seals are often used to seal connections in the fuel feed system --the turbo pumps used in rocket engines. These connections are notoriously difficult to seal due to rapid temperature changes and high pressures. On top of that, the fluid being sealed can be extremely low temperatures down to negative 300 Fahrenheit and can be highly reactive. Parker's PTFE-coated C-Seals are chosen in these types of applications due to their ability to maintain seal performance in extreme conditions.

Speaking more generally, Parker's metal seals are chosen in a wide range of space exploration applications, on programs ranging from landers, rovers, probes and satellites. Our seals have been chosen on a variety of these projects for a wide variety of reasons and uses. For example, some seals have been chosen as a simple debris seal where leak rate was not a concern but the seal had to withstand temperatures of outer space. Some applications have strict leak requirements where a vacuum must be maintained during extreme temperature cycling. And some applications use a metal seal where an elastomer would function, but there were concerns of a limited lifespan.

To make the point clear, there is not a single use for metal seals in low temperature aerospace applications. There's a wide range of uses. If you or your customer has a specific sealing challenge, please reach out to a Parker application engineer and they would be happy to help you find a solution.

Lastly, I'd like to touch upon Parker's offering of dynamic seals. Up until this point, Tyler and I only discussed static seals, as that is the focus of both Parker OES and CSS (divisions).

However, Parker's Engineered Polymer Systems Division offers a wide variety of safe solutions for dynamic applications. Parker's dynamic sealing products can be broken down into two major groups linear and rotary sealing. For applications that have linear motion, such as hydraulic, pneumatic or electrical actuators, it is important to keep the devices properly sealed. The media being sealed can range from hydraulic fluid, lubricants or debris. For these applications. Parker offers a variety of products from T-seals, wiper seals and wear rings. Parker's experience is best utilized in custom solutions where Parker engineers can design custom sales for your unique application by taking the strengths of various types of seals and combining them into a unique solution. These linear seals are often found in linear actuators that control flight control surfaces such as the rudders and wing flaps, or extend and retract landing gear. These systems are often exposed to atmospheric conditions outside the aircraft, so it's important for these seals to be able to withstand temperatures of below negative 65 degrees Fahrenheit.

Another category of dynamic seals are rotary seals. There's various options for the rotary seals, such as FlexiSeals® and FlexiLip™ seals, which are machined from PTFE, as well as Clipper® seals, which are molded elastomer seals.

Custom solutions are also available, where features of these seals can be combined into one unique solution. Examples of these applications are gearboxes in both helicopters and fixed wing aircraft. Air management systems, engine drive shafts, bearing compartments, and wheel and brake systems. As with linear seals. These systems are often exposed to the environment, so maintaining sealing ability at extreme low temperature, so maintaining sealing ability at extreme low temperatures is necessary.

Many of Parker's dynamic seals are available for use at extreme temperatures due to Parker's wide material offering. Choosing the right material for your seal is critical. There are three broad families of materials used by Parker EPS (division). First are thermoplastics. Most commonly used are nylon and PEEK. While both of these materials do boost activity, and strength at low temperatures is not a concern, since these materials are primarily used as backup rings which do not rely on these properties.

Second are thermosets such as elastomers. These are the same type of materials that Tyler already discussed. In fact, Parker EPS uses some of the exact same materials that Tyler mentioned, such as the FKM VX065, which is suitable for use down to negative 65 degrees Fahrenheit. Also popular for low temperature applications are nitrile EPDM materials such as EM163 which can be used down to negative 60 degrees Fahrenheit.

Lastly, PTFE and PTFE-based compounds are some of the most useful and versatile compounds to be used in low temperature dynamic seals. Most commonly modified and filled PTFE's are used in such applications and will be able to accommodate temperatures down to negative 250 degrees Fahrenheit. Their low temperature capability and low friction coefficient makes them ideal dynamic seal materials.

For more information on any of these seals discussed on today's webinar, please reach out to Tyler or myself and we'd be happy to assist with that.

This concludes our webinar. Thank you for your attention and we will now move on to questions.

Thanks, Max. So the first question we have comes in here and asks: "So Tyler mentioned that TR10 is a method to use low temperature capability of elastomers. Sometimes I see Tg reported for low temp. What is that and how does it differ from TR 10?

So that's a good question. Tg is basically the shorthand way to say glass transition temperature. And oftentimes it's a it's a different method used to analyze a low temperature capability of a material. It's a more analytic way in terms of instead of taking an actual sample, stretching it, cooling down and doing a very manual process, you simply put a sample of the material into an analytical machine and through various processes, it measures how heat is transferred through the material as it's warmed up. So it's an electronic analytic measurement. But fortunately, you often see that the glass transition temperature and the TR10 temperature of a material is typically no more than maybe one degree Celsius off from each other. So it's very similar to TR10. Parker also can test Tg as well. And it's simply a different way to get the similar type of result for a low temperature capability of a material.

Hey, this is Max Miller, and I'm going to take the next the next question. This one comes from Ryan. And I'll just read it really quick. "Is there a concern about galvanic corrosion when using the Inconel 718 metal seals with carbon/alloy steel components? How would one mitigate corrosion between 718 seals and a carbon alloy steel component?"

And to answer that, you know, you really need to understand the galvanic potentials of each alloy that you're talking about; the first one being Inconel 718, another one being some sort of steel alloy. And, to be honest, off the top of my head, I don't know the galvanic potential of 718, so I can't give you a direct comparison. But Rory, I can follow up with you on that and give you some more details after I do a little research.

To answer your second part, "How would one mitigate corrosion between the 718 seals and the carbon alloy steel component?" There's a couple of different ways to do that. I think the most obvious one, the easiest way of preventing it ,is putting some sort of barrier between the two components. And Parker offers a variety of different electroplatings or coatings as well. You know, whether or not the silver or tin plating or even a PTFE (Teflon®) coating. So it really comes down to the exact, specific application of which plating or coating you will use, but that would be the most common way of preventing galvanic corrosion.

This is Tyler again. We've got another one on the elastomers side in terms of sub zero elastomer seals for dynamic applications. "How close are we to the Tg at the seals minimum temperature range? Viscous losses are maximizing your Tg, so friction wear values are very large. Is there any information on this?" So I briefly mentioned at the very beginning, so when we do these type of analytical tests or the TR 10 tests to determine the low temperature capabilities, we take the TR10 and then you can either take 15 degrees Fahrenheit below as the minimum static temperature at which we recommend that seal - or translates to about 8 or 7 degrees Celsius below. So there is a range where you take this recorded value and we say the static capability is a little bit below. On the dynamic side, however, our recommendation is to not use any type of elastomeric seal in a dynamic application below its recorded TR10 or Tg temperature. So if the Tg of a material is minus 40 Fahrenheit, we can say you can use it statically down to about minus 55 Fahrenheit. But we would not recommend using it dynamically below that minus 40 Fahrenheit TR10 or Tg value. So that's our recommendation on dynamic applications in low temperature for elastomers.

Next we have a question for metal seals. "Do metal seals become permanently deformed, or can they be reinstalled?" And the answer to that, generally speaking, is metal seals do permanently deform on use. But the level of permanent or plastic deformation that occurs is really going to depend on the specific cross-section chosen. So if you're using a higher load, less resilient cross-sections, such as the C-seal, you're going to see more plastic defamation. Whereas if you're using a more resilient lower load cross-section such as an E-seal, there's going to be less deformation. But in general, Parker's standard recommendation is due to this plastic deformation, the performance of the seal after each use is going to diminish, so we wouldn't recommend it for re-use.

I have another question that came in kind of a specific one, but "Is VX365 available in cord? Can it be glued?" So both the VX065 and the VX365 materials have been extruded and spliced. Parker uses a hot vulcanization process. We don't do any cold splicing, super gluing or anything like that in our facilities. Really, to get into specifics about an application, you would absolutely want to contact an application engineer if it's if it's an interesting shape. But in very simple circular shapes, standard cross-section profiles, those materials can be extruded and spliced.

All right. The next up, "How do you measure leakage for static seals?" This is a bit of a generic question. The answer really depends on your application and what your requirements are. Each Parker division does have specific leak test setups that we could use. But really, all depends whether you're looking for, you know, nitrogen leak test, a helium leak test or some other type of specific leak test. So to answer that question, I would ask you to reach out to a Parker application engineer, and we can talk to you about our capabilities in terms of testing.

I had another question come in about the VX065 material. "The MIL spec you mentioned, the AMS7410, is it currently available from OES for the VX065?" So I briefly touched on it. This is maybe one of the newest MIL specs that the SAE committee has come out with in general. Our team of engineers have been involved in those discussions at the national level and with that organization all along the way. The material's been tested and it is -- it meets that spec and will be certified to that spec. Really, what it comes down to is, as far as I'm aware, we've seen very little demand from it, from the industry side. So once that spec becomes more well known and users start putting it on their drawings, Parker will absolutely have the capability to certify that material to that MIL spec.

The next question is "What are the performance differences between copper seals and the Inconel alloy?" So with that being said or that question being read, I would say that Parker doesn't offer a wide range of copper seals. We do offer a copper wire seal, which is an extremely high load -- virtually no resiliency in a wire seal. So for the Inconel alloy, that is going to give you a much wider range of options in terms of what seal you're able to use. You can use an Inconel alloy for our most resilient seals to our highest load, lowest leaking seals. So I would just sum it up with the Inconel alloy is going to give you a lot more options.

Got a question asked, "What material would Parker recommend for valve stem seal for a cryogenic application?" So part of that would come down to specifically the chemical or fluid or what's being sealed in that low temperature application. Depending on the chemistries, you might pick a specific type of elastomer that would have low temp capabilities. Again, if it's something pretty basic like air or extremely low temp, oxygen or nitrogen or something, something pretty standard, you could use that S0383 as well and that extreme low temp environment, but might have to understand what the chemistry is you're sealing. to get a specific recommendation with material family.

Another question from Frank, we're going to have dynamic seals. "Do the dynamic sales have recommended PV values or is it more of a test and see situation?" And Frank, to that question, I believe that we have some stated values in our design guide and catalogs. But I will reach out to you directly to get you some more information and get you in contact with an application engineer at the EPS Division to answer that more more clearly.

We get a question from Chris asking about, "Do you have any butyl rubber seals which have a low compression set less than 15 percent for temps of minus 40?" Looks like he uses some seals and some pretty specific packages .."Competitors have only been able to meet various requirements." Yes, even though we did not mention that material family in this presentation, we do have butyl rubber. In fact, we have B0612 which does go down to minus 75 Fahrenheit. It's been used very regularly in aerospace applications. I believe it's been used in nuclear applications as well. It has a lot of pedigree within the elastomer market. We've , we've had that compound around for quite a while. And have used it in many different capacities. It would absolutely be good below minus 40 Fahrenheit. And I believe it has a pretty good low compression set rating as well.

The next question, "What material besides PTFE will be good for negative 423 Fahrenheit, liquid hydrogen?" To answer that's really going to depend on the specific application. If you're looking at a dynamic application, the PTFE is probably a virgin PTFE is going to be your only option. Whereas if it's a static seal, you would be able to potentially get away with using a metal seal. But it's really going to come down to the specific details of your application. So again, I would recommend you reaching out to a Parker application engineer, and they'll certainly be able to point you in the right direction.

We have another request for, it looks like somebody says they "...Need very low temp FFKM's around minus 65 Celsius for cryogenic etch applications in the SEMICON market. Does Parker have any material development for this?" So as mentioned as far as I'm aware at this time, our FF400 is the best in class of any FFKM material at the minus 40 Fahrenheit and minus 40 Celsius. They are the same kind of benchmark there that temperature. So at this moment, we do not have something that goes all the way down to minus 65 Celsius, which I believe is about minus 80 Fahrenheit for a FFKM. But this is something that we should certainly-- if there is a large demand for it-- getting in touch with an applications engineer at our OES Division is a great way to start the conversation and see if maybe if an FFKM may not work, if there's another material family that might work in that specific application.

We have another one as well, "Is the VX365 material available for packing for valves?" Yes, we we do manufacture that material in O-rings, mini valve applications, any type of custom applications as well.

That was another question I saw, "Do we make custom molded seals out of this?" Yes. The materials we mentioned in many cases, if there is a custom shape type of design that is specific that you need, we can certainly look into what our engineers can do to design and to manufacture non-circular non- O-ring type seals out of these applications and materials as well.

And we have two more that we will answer, so "I'm familiar with AS3209, which aligns with FKM O-ring's X75, is there an industry standard that aligns with VX065 and GLT FKM?" So yes, as mentioned, the VX065 -- that's the brand new AMS7410 hot off the presses for that one -- that's for the VX065 material. And then our GLT FKMs are the AMS7287 spec. Parker has materials that meet those. And again, that AMS7287 meets or kind of calls out the guidelines to manufacture and the properties for a minus 40 Fahrenheit GLT- type FKM.

And then, "Do you offer any O-rings made of AMS-R83412-1, hydrazine resistant EPR?" So we do not have any materials that meet that specific spec, that AMS spec, but we have had good history with our E0540 material in hydrazine type applications. And if there's a specific situation, specific application, an application engineer may be able to work through that and see if that material -that EPDM -could work for that. But as far as certification to that spec, as far as I'm aware, we do not have a material that meets that.

All right, it looks like that that's all the questions we have. Feel free to reach out to Tyler or Max. Their information is on the screen. We will send out a recording of this webinar as well as have it posted to Parker.com/OES under our Solutions tab. When I conclude the webinar a survey will pop up, so please take the time to fill that out and answer any future topics of interest.

Thank you all for joining us today. We really appreciate it.