NES is at the forefront of technological development for the UK space sector. The UK space sector has been growing and going from strength to strength in recent years as we, as a nation, look to position ourselves as a leading manufacturer.

We provide a number of different seals to be used in this burgeoning sector, being at the cutting edge of developing and testing new materials to be used in high-pressure environments.

Alongside our sister company Rubbercraft, we are able to offer fully approved materials, supported by our wide-ranging experience, within the Group which extends to EMI-RFI shielding. We a

Why technological development is important

With space being such an unstable environment with a high potential for unforeseen mishaps it is extremely important that all the machinery and parts required are of the highest specification for safety and cost-effectiveness. It is important that we, as NES and the UK space sector as a whole, push for further product development to build the industry and remain at the forefront of it.

Regardless of the practicality of good-quality space components, constant product development is essential to the UK becoming the first choice for engineering within the space sector. Doing so will help to grow the space sector within the UK and subsequently boost the economy and provide jobs.

NES rigorously tests all elastomeric seals, no matter the industry, as we know that mishaps are unacceptable. We have a proven track record of supplying top-of-the-line seals to a number of industries that operate in the harshest environments.

As the industry grows, so do the requirements. Constant technological development in seals is important to ensure that our products are up to spec with the newest technology. This is key for functionality and overall safety. This is something we have done in the nuclear and aerospace sectors with great results and it is essential for us to continue to do so in the space sector.

What are the technological developments NES provides the space sector?

Our main products are an ever-expanding line of elastomeric seals with a proven track record of success in harsh environments.

NES offers the optimal choice of material compound; expertly developed with an excellent standard of project management and, above all, technical support. We are as renowned for our responsiveness and agility in finding the right solution as our product development and rigorous testing.

Sealing is particularly important when it comes to space as the harshest environment requires strong sealing for functionality and safety. We have developed a superb line of bladders, P seals, airframe seals, vacuum bags, extrusions/O Rings and custom mouldings to be used in conjunction with other mechanisms within the space sector.

All the materials we use are of the highest grade and have the ability to withstand the extreme environment of space with little issue.

The nuclear sector is among the most demanding energy sectors when it comes to what is required of materials used in energy production.

As producers of seals that will be put to use in crucial areas, we must rigorously test all the different types of materials and seal shapes we use. That way, if we encounter any faults during initial testing, we can develop solutions or, in some cases, entirely new products better suited to the job.

Elastomeric Sealing

Our main products for use in the nuclear sector are our range of elastomeric seals.

NES elastomeric sealing solutions utilise premium materials, including NORSOK-approved polymers that offer a useful mix of chemical resistance and extreme temperature performance.

When we develop elastomeric sealing solutions for nuclear, we rigorously test our products, naturally, with a key focus on these areas of resistance:

• Temperatures as low as -46°C (-51°F) or lower – NES elastomeric seals undergo rigorous temperature tests to ensure they can handle the lowest possible temperatures they will ever encounter. 
• High-temperature & high-pressure environments – Conversely, it is important that elastomeric seals can also deal with high temperatures. This extreme temperature functionality is what makes elastomeric seals doubly suited for use in the nuclear sector. Furthermore, elastomeric seals perform well in high-pressure environments, subterranean and underwater locales for example, which only adds to their usefulness. 
• Resistance to a wide range of aggressive chemicals – No matter which part of the nuclear process the chemicals are used in, our elastomeric seals are guaranteed to be able to withstand all commonly used chemicals and numerous others. 

All of the above factors are important within any of the energy sectors in which we operate, but doubly so for the nuclear sector where safety is of the highest importance. 

Membrane Technology

NES has worked extremely hard, tirelessly, to develop our range of seals using membrane technology to outperform most competitors being utilised within the nuclear sector. Choosing an NES seal guarantees you a high-standards where performance, durability and value are concerned. 

We like to manage and nurture relationships, which is why we put such a focus on aftercare and after-sales support. This is not only to help clients with any unforeseen issues but also to get feedback on the products which we can then utilise in future research and development to continuously improve and make the best products for use in the nuclear sector.

Membrane seals are all custom-made to suit a diverse range of applications. All of these seals are top-of-the-range and feature the highest quality imaginable for sealing solutions.

Our membrane seals feature:

• In-house extrusion or moulding – Using either of these offers complete control over dimensions. Extrusion moulding allows for materials to fit a number of different shapes, sizes and therefore environments.
• Patented membrane technology – This is essential for wrap-around sealing which subsequently saves downtime and reduces costs.
• A huge range of available materials – Materials include: EDPM, Silicone and Viton™
• The support of expert engineers – Our team of experts are always on-hand to assist with custom orders and fulfilment of complex requirements.

 

Astra seals are a unique seal developed for extreme temperatures to provide sealing in high-pressure environments. This is a pressure sealing solution developed and manufactured by NES and there is really no better sealing option for cryogenic application.

NES’ Astra seals have been successfully used in a number of space shuttle and rocket launches, our Astra seals are favoured by leading manufacturers like Boeing, NASA and Lockheed.

Extended rigorous testing in harsh environments has shown that the NES Astra Seal outperforms FFKM for compression sets.

Created by an Aerospace Engineer to combat the harsh environments associated with liquid oxygen and the problems associated with sealing other cold media, such as liquid nitrogen and hydrogen, the Astra Seal copes perfectly with the extremely low temperatures which make most O Rings brittle, which in turn leads to failure.

Astra Seals are composed of multiple elements all of which are selected to perform perfectly in extremely low temperatures. One of the primary applications of our Astra Seals is within the space sector, where materials that perform in extremely low, cryogenic temperatures are essential to maintaining the functionality of space crafts, shuttles and rockets. Proper materials and sealing are extremely essential within the space sector for safety foremost but also tyo avoid wasting money as faulty products can be extremely costly for space launches.

Below is a breakdown of the different seals which are generally utilised for cryogenic application. The attributes required of seals for cold temperatures are evident and therefore temperature resistance is absolutely paramount but not the only requirement.

What is required of seals for cryogenic application?

Cryogenic refers to extremely cold temperatures. Considering this, materials for seals are required to be functional under extremely low temperatures. There are many seals out there that claim to be able to withstand low temperatures and, while this may be true in part, most of them are too brittle to withstand cryogenic levels and are simply developed for colder-than-average applications.

Astra Seals from NES are developed to deal with elements like liquid oxygen, liquid nitrogen and hydrogen and maintain functionality.

Why Astra Seals are superior

NES’ Astra Seals are a type of O-Ring but Astra Seals differ greatly where it counts, when it comes to extreme temperatures.

Traditional O-Rings turn brittle when faced with truly extreme low temperatures, while Astra Seals are developed to mitigate the risk presented by cryogenic temperatures. The Astra Seal is comprised of 302 strainless flat-wound ribbon spring which is then encased in either FEP or PFA jacketing to form the O-Ring. FEP performs in temperatures between -250°C to 204°C (-420°F to + 428°F) and PFA functions in temperatures between -250°C to 260°C (-420°F to + 500°F).

Astra Seals come in a number of sizes so they can be adapted for a number of fittings for a variety of different mechanical elements. This size adaptability perfectly suits their ability to adapt to extremely low temperatures alongside the material variations mentioned above.

The renewable energy sector is growing every year with demand continuing to rise and technological advancements occurring at a rapid pace to meet the demand. Sealing for machinery and systems is important as not only does it literally help to keep the whole thing together but it also factors in massively to the overall functionality and maintenance of the renewable energy system.

When considering sealing options for the renewable energy system, it’s important to note the primary renewable energy forms are wind, hydroelectricity and geothermal. All of the afforementioned system types will present a number of different potential problems that will require adequate sealing to manage properly.

NES elastomeric sealings are developed specifically for the energy sector. This means they are extremely durable, being able to withstand extreme temperatures both low and high, high pressures and resistance to chemical damages.

It’s important to consider all the factors which the seals will impact or be impacted by before making a decision on which option to choose. Here are the factors to consider when choosing the best sealing for your renewable energy system.

 

Material

The material compound is essentially what dictates the solution to all the other factors on this list. NES offers seals for the energy industry primarily using four different compounds, each of which have their own benefits and are uniquely suited to specific tasks.

This section is essential in offering an overvie of the seal materials available and, combined with the other factors on this list, will hopefully help determine which seals work best in which environments.

 

EPDM

EPDM (ethylene propylene diene monomer) are an advanced formulation of elastomer with a variety of uses across a variety of industries. 

It’s worth noting that one of the major advantages of using EPDM for sealing is the compounds advanced temperature resistance. This elastomer performs amazingly in extreme temperature conditions of anywhere between -60° and 150°C which make it perfectly for renewable energy systems across the geothermal and wind sectors where extreme heat and cold respectively are unavoidable factors.

Furthermore, EPDM has a high resistance to a wide variety of chemicals and will be able to withstand the potentially detrimental effects of greases, sodium hydroxide solutions, mineral oil products, lubricants and fuels.

 

FKM

Made from highly fluorinated hydrocarbons, FKM is a copolymer with advanced resistance to ozone and atmospheric pressures as well as a range of media and general aging.

FKM is known for it’s ability to withstand pressure and high speeds as well as high temperatures. This makes FKM a good choice in systems with a lot of fast-moving, kinetic machinery. 

 

Silicone

Silicone is a highly resistant elastomer known for it’s thermal stability which is well-suited to mechanical application all across the renewable energy sector. Silicone is extremely heat-resistant and continues to function well in even the harshest climates, in temperature ranges of -73° to 260°C offering superb electrical insulation as well as sealing for high-temperature liquids.

On top of its heat-resistance, silicone is also extremely flexible hile also being durable and age-resistant. Silicone can maintain its shape and last for decades even in the harshest of temperatures.

 

Nitrile

Nitrile, or as it’s more commonly known NBR or Buna-N is a synthetic rubber composite of acrylonitrile and butadiene.

Nitrile seals are highly temperature resistant, however, most of their resistance benefits dry heat situations. That being said, nitrile seals will maintain their flexibility in high temperatures. 

However, Nitrile seals have a selection of other advantages and benefits to be put to use across the renewable energy industry.

Nitrile is extremely resistant to chemicals such as oil and fuel, greases, hydraulic fluids, water and different types of alcohol. Nitrile has a lo compression set and high tensile strength as well as high resistance to abrasions.

 

Temperature 

Temperatures both low and high are common in the renewable energy sector, particularly with wind and geothermal operations respectively. When factoring in that sealing is necessary to join mechanical mechanisms together, resistance to extreme temperatures is essential.

With most wind energy systems or wind farms, the machinery will be exposed to low temperatures as well as wind and rain, as they are primarily offshore, therefore any sealing used on these will have to be durable enough to literally weather a storm with little damage.

Most geothermal energy systems are subterranean and therefore experience the opposite problem to wind systems as they will be exposed to extremely hot temperatures.

 

Chemicals and Potential Contaminants

When it comes to wind, humidity and moisture can cause big problems to sealing not made from a durable material.  With offshore wind farms rain and sea spray is guaranteed, therefore it is essential to fit any machinery with seals capable of withstanding this contaminant.

 All energy operations will reqquire use of chemicals and/or at least some exposure to contaminants, there are many seal materials that work in these situations such as silicone, FKM and nitrile.

 

Size

Naturally, depending on the type of renewable energy you’re working with, different sizes will be required. Largery machinery like wind turbines will not only require larger seals but they will probably require a mix of different sizes throughout.

Size seems obvious but it’s important to consider the size you are working with as well as the seal size you need to fully guage suitability.

 

Shape

O-rings are probably the most common type of seal from NES. As the name suggests, these seals are circular in the shape of a ring or the letter ‘O’ and are well-suited to a myriad of different machines and systems.

Other shapes or styles include our Astra seals and precision moulded products. We also offer bespoke seals custom made to fit any machine perfectly alongside our traditional range of products.

As the wind industry goes from strength to strength it becomes more and more important that turbines also become more sustainable, easy to maintain and reliable. Selecting the perfect sealing is key to preventing current and future problems.

It’s important to note where wind turbines are typically erected when considering the importance of using the right materials and seals in conjunction with them. Turbines are placed in areas with extreme weather conditions such as large hills, mountainous regions and most often in the sea. 

All of these varied locations have one thing in common which is the severe climate conditions they all experience. Considering this, elastomeric seals are ideal for use on wind turbines due to their enhanced durability as well as their temperature and chemical resistance.

So, what is an elastomeric seal? Well, elastomeric seals are made by cross-linking macromolecules with a number of vulcanization additives. This chemical bonding means that the seals hold their form and do not melt or decompose when they come into contact with high heat or other extreme temperature and chemical situations.

Elastomeric seals are extremely strong and durable which makes them perfect for use on wind turbines both on and offshore. Considering that the majority of wind farms are offshore, elastomeric seals make the most sense as you do not want to make maintenance calls a regular thing – this is inconvenient for all parties involved. The right seal can have a big impact on the service life of individual turbines and whole systems. 

There are various forms of elastomeric seals, the most common being the O-ring but there is also room for more complex multi-component sealing systems to be used on turbines and in wind systems. The basic requirement of an elastomeric seal is that it prevents media from escaping or entering which in turn proves critical to the overall function of the system.

Using elastomeric polymers when crafting a seal means they are resistant to ozone contaminants, salty air, UV rays and extreme temperatures. These factors are unavoidable with offshore wind farms and therefore using an elastomeric seal is a perfect choice. With most rubberized seals, ozone containment will cause cracks and begin to break the material down while UV rays will affect the overall structure of the seal, this is where elastomeric seals’ chemical bond comes in to help it stave off both of these issues.

After evaluating all the previously mentioned factors and taking into consideration the effects of mechanical loads, greases and other media on the seal, we conclude that using an elastomeric seal is the best solution. The aim of NES here is to extend seal service time and subsequently improve the operating costs of wind farms and systems. 

NES offers elastomeric seals in a range of different styles and sizes to suit the majority of systems currently in operation. However, we also offer bespoke seals to suit any application within the wind industry.

NES is here to support the wind industry and feels fully invested in the strive towards becoming energy sustainable – we are happy to play our part by providing top-of-the-line elastomeric seals, the best option for sealing solutions in the wind industry.

O-rings are a crucial component and are vital to the overall performance of your application. Despite this, they are something that many take for granted without thinking about what would happen if they fail. Essentially, they become an afterthought.

However, O-rings are an integral part of your machine and application because, without them, things would become problematic quickly. The smallest fault, tear or nick in your O-ring could lead to leaks, damage to equipment or a complete failure. What’s more, they could also cause contamination issues in food or pharmaceutical manufacturing and that could pose a health and safety risk to the public. So, even if you might think that there is a problem with your o-ring or believe that it needs changing then it makes sense to do it because the implications of not doing so could be catastrophic.

The cost of a small replacement against the cost of the damage caused as well as downtime and man-hours that are lost cannot be compared. So, it’s simply not worth trying to use the same O-rings or continue knowing that there might be a potential problem or fault.

Regardless of the type of O-ring you are using, they all have a certain shelf-life. When you consider the likes of Polyurethane and Styrene Butadiene which have a short shelf-life and the likes of Viton, which has an unlimited shelf-life, it is clear to see that they are different. However, regardless of how different they might be, when they are put to use they both become just as likely to develop problems through becoming worn, torn or damaged.

Essentially, the main thing to consider is that you shouldn’t take them for granted. They serve their purpose but why avoid replacing them at a minimal cost when you face the risk of significant problems otherwise. So, it’s worth remembering that if your O-ring fails, your entire system could be brought to a standstill and that will always prove to be costly.

To find out more about NES O-rings, contact our Sales team at sales@nes-ips.com

With many types of fluoropolymers available, it can prove challenging to work out what is the best option. There are subtle variances in the structure of PTFE, FEP and PFA and they all offer something different but what are the main differences between these three materials?

PTFE

Polytetrafluoroethylene is also known as PTFE and was one of the first synthetic fluoropolymers to be made. It is ideal for creating coatings that have non-stick properties which makes it ideal in applications such as cooking or food manufacturing. As it is hydrophobic it has a high level of electronegativity which means that liquids will not affect it.

FEP

FEP is also known as Fluorinated Ethylene Propylene and it has different properties when compared to that of PTFE. However, it does have non-stick properties which again makes it suitable for use in applications where residues or oils are likely. FEP does have a softer makeup when compared to that of PTFE and that means that it can melt at a lower temperature which means that it is not suitable in applications that are exposed to high temperatures. Along with this, it is also transparent while it is resistant to sunlight and UV which makes it suitable for use in applications that are exposed to the elements.

PFA

Known as Perfluoroalkoxy, PFA has alkoxy substitutes that mean that the polymer can be melt-processed. However, it also differs from a molecular level as it has a smaller chain length than other fluoropolymers. It is extremely durable which makes it suitable for use in demanding application. It is also the preferred option when it comes to choosing a material that requires high chemical resistance as well as high purity and low stiffness while it is also extremely durable when it comes to resisting weathering. It has a lower melting temperature when compared to PTFE while it has great insulation properties and is UV resistant which also adds to its durability.

When it comes to compound deterioration, heat is one of the most destructive forces. Therefore, understanding “what is the best high temperature O-ring” is a crucial factor. If you are working with temperatures over 150°C then there are a number of materials you can consider such as FKM, FVMQ, and FFKM to name but a few.

O-Rings for Automotive Oils, Fuels And Gases

Viton is one of the best all-round materials available, particularly when used with oils, greases and fuels at high temperatures. An alternative to this is the Polyacrylate or ACM as it is known has resistance against mineral oils as well as engine, gearbox and transmission fluids. ACM O-rings have the ability to withstand temperatures of 150°C.

Hydrogenated Nitrile or HNBR has a top temperature of 140°C and again, this is compatible with automotive fuels, oils and gases although it is not suitable for use with chlorinated hydrocarbons or strong acids.

TFE/P or Aflas has the ability to handle the majority of chemical mediums that are used in automotive sealing. It has the ability to withstand a temperature of up to 204°C.

Silicone or VMP O-rings offer temperature resistance of up to 230°C and some variants of this material can handle up to 300°C. These are commonly used where there is high exposure to UV, ozone and weathering although they are not suitable for use in hot water, chemical or dynamic applications.

PTFE O-Rings have the ability to handle temperatures of up to 250°C and offer chemical resistance to acids, alkalis and solvents. In actual fact, it also has the ability to withstand temperatures as low as -200°C.

FEP comes from the same range of materials as PTFE. While it has many of the same characteristics, it can only work to a temperature of 204°C. These seals are both chemical and heat resistant, much like PTFE although they do offer an increased level of flexibility.

FFKM is also known under brand names such as Perlast, Perflour and Simriz. This is available for use in a range of applications and so, they are available in a range of material grades and this enables them to operate at temperatures that range from 230°C to 320°C.

 

 

In order to identify the biocompatibility of materials, USP Class VI testing is required. As one of the most widely used methods, VI forms part of six different classes with this being the most thorough. This form of testing is developed to certify that no harmful reactions or long-term issues are caused to the body by chemicals that are released or leached from plastic materials. The United States Pharmacopeia and National Formulary (USP-NF) determine the USP Class Testing standards, and so, this organisation is responsible for ensuring that medical devices and foods are safe. The testing is carried out frequently, especially those plastic materials that are regularly in contact with injectable drugs as well as a range of other fluids that are seen during the many steps involved in the drug manufacturing process.

What Are the USP VI Testing Methods?

Testing is carried out through producing an extract of the product using different extraction fluids which can include Polyethylene Glycol and vegetable oil. This is then injected into a specimen that is alive in order to see how it responds. This is carried out regularly and requires three forms of testing including systematic injections, intracutaneous and implantation.

Systemic Injection Test – During this test, test specimens are injected with the extract intravenously and monitored for 72 hours. They are monitored to identify any reactions that relate to abnormal toxicity level.

Intracutaneous Test – This test is carried out to identify whether any local skin reactions take place. The specimen is injected intracutaneously with the extract before being monitored for 72 hours. Any reactions are scored and averaged.

Implantation Test – The product materials implanted into the specimen to identify whether a reaction in the live tissue takes place after coming into direct contact with the product over a period of around five days.

What’s the Reason for Products Being USP Class VI?

Class testing is needed when manufacturing drugs to identify its low toxicity compliance while ensuring it meets all biocompatibility standards. Therefore, it is crucial to identify that any fluid contact surfaces will not leach harmful chemicals into the fluid during manufacturing. Class VI testing vigorously investigates where there is a reaction in the skin, body and living tissue, ensuring that a product is safe for use.

O-rings are a crucial element in manufacturing and the operating of machinery but when it comes to installing rings, it is important you know what to look out for.

When it comes to installing O-rings, it’s important that you get it right from the beginning as this will help to save time and money. Therefore, these installation tips can help you to avoid problems that could cause issues with applications further down the line.

Choose the Right Size – It’s crucial that you choose the correct size O-ring. If you go for one that is too small, then they tear and break while too big will not achieve the correct seal.

Don’t Overstretch – Every O-ring has a maximum stretch potential and if you overstretch them then they can break and tear during use. Therefore, it is crucial that engineers make  sure that the stretch does not go beyond that of the maximum elongation of the O-ring. What’s more, it is also crucial to stretch the O-ring evenly.

Don’t Roll It – When sliding an O-ring down a shaft for installation, it can cause the O-ring to spiral. When this happens it means that they cannot be installed correctly and that means that they will not do their job properly. This can then lead to leaks or damage. The O-ring should be slid into place as this helps to stop spiralling. If you are having problems, then lubricant can help.

Be Aware of Threads – O-rings are commonly fitted with threaded parts but these can commonly cause the O-ring to tear. When installing over a thread, cover the thread with masking tape as this will help the O-ring to slide over the threads without being damaged. If required, it is possible to use lubricant too.

Avoid Sharp Edges – Sharp corners and edges are often seen in manufacturing machinery and application and these can cause problems with O-rings. Some tears are small enough to go unnoticed which means that they can cause significant problems. So, don’t force the O-rings onto sharp corners or edges but instead attempt to use a lubricant to slide them into place if necessary.