Samuel Bramwell

Where Are Inflatable Seals Used?

Inflatable seals are designed to provide a solution when it comes to sealing against powders, gases, liquids, dust and granules. They are generally used to seal fabricated equipment where the sealing gap can vary while they are useful in instances where assembly and disassembly must take place quickly. They are also suitable for use where hygienic procedures exist.

But where are they used?


Marine Applications

These seals provide a watertight solution for door applications and sliding windows while they are also used in transom and salon doors on yachts. As they can be fitted into machined grooves, frog leg and channel fit profiles are commonly used.

The Handling of Powders and Solids

They are commonly used in food processes and pharmaceutical industries where powders are transferred and require an airtight seal. This can include the likes of bulk bag filler seals, hopper seals and seals for viscous pumping equipment.

Energy Generation Industry

Inflatable seals are used in the energy generation industry and in particular, nuclear power. They are suitable for meeting the tight tolerances as well as the tight quality control that needs to be put in place. They are used to seal pool gates in nuclear power plants while they are also used to seal airlocks, access door and equipment hatches.

Airtight Doors

Inflatable seals are ideal for ensuring a positive seal is achieved on doors that require an airtight seal. As they expand towards sealing, they can handle variations in the tolerances when the door is manufactured. While they create a positive seal, they also provide frequent access as they can be inflated and deflated. They are commonly found in chemical processing plants, laboratories and research facilities.

Aerospace, Transportation and Defence

All of these industries use inflatable seals for both bespoke and technical applications. Inflatable seals are used to deliver uniform pressure when bonding airframe components while they are also used to seal wind tunnels.

Inflatable seals can also be used to create watertight seals on military and other vehicles. In many cases, USP Class Vi and FDA certified, making it suitable for use in a range of industries. They can be developed to be heat and water-resistant, making them the perfect sealing solution across a variety of uses.

If you have an application that you think could benefit from an Inflatable Seal, contact the NES Sales Team at


What are the benefits of inflatable seals?

An inflatable seal is an elastomeric tube that can be made from several different elastomers or can also be fabric-reinforced and custom molded in a concave, flat or convoluted configuration. It is designed to round out when inflated to ensure that a tight barrier is created between a mounting and a striking surface.

How Does an Inflatable Seal Work?

When the inflatable seal is introduced and inflated, it will expand to the striking surface which helps to create a reliable seal that can prevent liquids and gases from escaping. When the inflatable seal is removed, the seal will retract to a deflated configuration. This helps to create a level of clearance that enables one or both surfaces to move freely.

How Is an Inflatable Seal Inflated?

Naturally, the most commonly used medium when inflating a seal is regulated air. The inflatable seals have to be inflated in line with the specific parameters of the application to help achieve the optimum operating pressure. In certain instances, some applications may require liquid to inflate the seals. This medium is introduced through a stem which is commonly a flexible hose that is securely connected to the inflatable seal using an integrally molded fitting.

What Are the Benefits OF An Inflatable Seal?

There are a number of reasons why an inflatable seal would be used over other sealing methods. Of course, the correct seal has to be used but an inflatable seal does provide a wealth of benefits.

An inflatable seal provides a leak-proof seal when preventing gases or liquids from escaping while it also provides clearance when required. It also provides a simplified design of the structure and hardware while it reduces the need for close machining or fabricating tolerances. Along with this, it is not exposed to compression set which can reduce the effectiveness of other seals.

Inflatable seals can be installed in a wide range of settings, whether that is radially in, radially out or axially.

So, inflatable seals are suitable for specific uses and provide an effective solution for many different applications. They are perfect for moulding to contoured shapes, offering greater flexibility while they can be inflated to suit the specific requirements of the manufacturing process.

If you think an Inflatable Seal could benefit your application, speak to our Sales Team at


How metal detectable o-rings can reduce downtime

One of the most important aspects of producing and manufacturing food and medicines in the food and pharmaceutical industries is that contaminants are kept at bay. If they enter the production chain, then it can bring it to a grinding halt and that costs money. However, while it is possible to mitigate risks, there is still every possibility that it can happen as unexpected particles from parts of the machine and deteriorate such as a rubber seal.

Seals form an integral part of the process in areas such as pipe couplings where ingredients pass through. While the seals are designed for long-term use, over time, they can wear and become brittle which means that they have the potential to enter the system and the process. If these are found in the final product then this can cause a huge range of problems such as having to stop production and recall products. It will also have an impact on consumers and what they think of the products, leading to a loss of sales.

Detecting Contaminants with Metal/X-Ray Detectable

If pure rubber is used within machinery, particles find their way into the process, they can be extremely difficult to detect during the control process. Therefore, there are special rubber materials that have been designed to overcome this problem as they can be detected by Metal/X-ray Detection or via magnets. The basic materials used for these products are EPDM, NBR, FKM and Silicones and all are specially developed materials for use in the food and pharmaceutical industries and so, they meet the specific requirements of the FDA.

Much of the equipment used in these industries will have X-ray and magnetism detection systems built-in and so, there is no need to adapt or modify the equipment in any way. Even particles as small as 2mm can be detected using this specialised equipment.

There is a wide range of advantages that come with using metal-detectable products. They are made from high-quality materials and they are designed to last. Whether they are metal detectable O-rings or coupling rings, they are all completely detectable and designed to help minimise problems.

Therefore, metal detectable O-rings can be easily and quickly detected, and this means that downtime is reduced as well as the need to carry out recalls which saves time.

To find out how Metal Detectable seals can benefit your application, please contact the NES Sales Team at

Everything you need to know about O-rings and seals

What is an O-Ring?

The O-ring has been around since the dawn of the 20th century. Amazingly, the overall design of the O-ring has remained the same although the type of material used has changed. However, in their simple form, they are extremely straightforward and reliable.

How Do They Work?

They take their name from their shape and they are designed to create a leak-proof seal between two components to prevent gases or liquids from escaping. Essentially, they are a form of gasket but the difference is that they are used in high-pressure environments. They sit in a groove or a channel between two surfaces that are then pushed together. The more pressure placed on the join, the more distorted the O-ring becomes, improving the seal up to a certain point.

How To Use O-Ring Seals

These are commonly found in pumps, valves, connectors and cylinders. The seal joins between separate components. These components can be static, dynamic, hydraulic or pneumatic and so, O-rings provide a flexible solution. Even when the compression forces are removed, the O-ring will return to its shape but over time it will need to be replaced.

Static and Dynamic O-ring Seals

Static O-rings are designed to make contact with two or more surfaces that do not move relative to each other. A dynamic O-ring will work with moving parts to provide a seal. In most instances, static O-rings are made using hard-wearing materials, however, the components used in a dynamic environment are carefully designed so they do not abrade, shear or destroy the O-ring. Dynamic O-rings will require more frequent lubrication as well as maintenance.

What Are They Used For?

O-rings are used in many ways and there are O-rings that are designed for a range of uses.

This can include O-rings that are made for:

● High-temperature sealing
● High-pressure sealing
● Chemical resistance sealing
● Engines
● Food and Beverage Industry
● Aerospace
● Chemical/Petrochemical Industry
● Co2/Gas applications

They are also manufactured using an array of materials and that means that they are suitable for different purposes. There are Viton O-ring seals, Nitrile O-rings, Silicone O-rings, Fluorocarbon O-rings, NBR O-rings and more.

O-rings are an integral part of many processes and provide an effective solution to prevent the leaking of gases and liquids.

To learn more on how NES’ O-rings and Seals can benefit your business, contact the NES Sales Team at

Choosing seals for medical and pharmaceutical uses

Sealing solutions are a vital part of nearly every industrial application but this is more important in those applications within the medical and pharmaceutical industries. Original Equipment Manufacturers (OEM) have the responsibility of ensuring that their products meet minimal requirements and so they offer quality and assurance when reducing the risk of cross-contamination.

Aside from keeping contamination levels low, sealing in the medical industry must also complement the mechanical performance and chemical resistance. Therefore, OEMs, should consider certain attributes when choosing a seal manufacturer.

Elastomer Materials

Sealing in the medical industry must be able to show that it is resistant to harmful and toxic materials. They must also be able to handle a wide range of process media, potent active pharmaceutical ingredients and rigorous cleaning routines.

There might be certain qualities required of the elastomeric material, depending on the medical application. Therefore, it is important to choose a seal manufacturer that offers a wide range of materials.

To guarantee chemical resistance, OEMs must prove that all of their medical sealing is manufactured using the highest-quality and highest-performing elastomers. Examples of these elastomer materials that are suitable for medical applications include perfluoroelastomers which are suitable for sealing applications where chemical resistance and high-temperature performance are crucial. Metal detectable elastomers are ideal for containment and controlling contamination.

Across industries, international standards show the quality in the material of a component. Therefore, when choosing sealing components that consist of high-quality, compliant materials you should look for FDA Approval as well as USP Class VI.

To ensure that OEMs adhere to the requirements associated with low contamination levels in medical sealing, they should choose sealing solutions that provide a range of services and engineering capabilities. One of the most significant for both medical and pharmaceutical application is cleanroom manufacturing.

Cleanrooms offer an exceptionally clean environment whereby manufacturers can examine their products, allowing them to ensure that every component that leaves their facility meets all quality standards and contamination levels.

Manufacturers will make and supply sealing solutions for a range of applications that are designed for human consumption which is not just in the medical or pharmaceutical industries but also dairy and food. Therefore, they should be able to demonstrate compliance with the appropriate governing standards that are put in place by the International Standards Organisation.

Contact the NES Sales Team ( to discuss your Medical and Pharmaceutical sealing needs

Critical Applications and Metal Detectable O-Rings

As a result of exposure to high temperatures as well as vibration and corrosive clean-in-place chemicals, it is common for O-rings that are used in industrial processing operation to fail. When this happens, fragments of rubber from gaskets and seals can shear off and that can mean that they then find their way into sanitary systems and even enter the product stream.

In many instances, the issue does not need much more than a short stoppage of the process in order to replace the O-ring.  However, this can prove to be a problem because of the fact that products that are made for the food, beverage and pharmaceutical industries and for human consumption are highly regulated and so, this can come with further problems.

In situations such as these, it can mean that the machines must be shut down by operators to carry out a visual inspection in order to locate the part that has contaminated the system. This then leads to unscheduled downtime, production losses and a reduction in safety. Should a fragment of rubber lay undiscovered and it then manages to reach the supply chain, the issues that can arise from this are extremely problematic and costly, especially if the product must be recalled.

Therefore, metal/x-ray detectable elastomer O-rings and seals have been developed to ensure that they meet the challenging demand of the food and pharmaceutical industries. In other industries, where resistance is required against temperatures and chemical and forms part of the key seal selection criteria, in food and pharmaceutical applications have to adhere to strict cleanliness and regulatory guidelines. These help to keep the entire process safe for consumers.

Metal/x-ray detectable O-rings can help to speed up the process of identifying them should they fail and this can help to reduce the risk of contamination through early detection and containment. As a result, there is a reduction in the risk of polymers finding their way into the final product and the supply chain. Should the rubber from a standard seal fail and break down and then find its way into the product then this becomes almost impossible to detect while it is also very time-consuming.

Using conventional metal/x-ray detection techniques, metal/x-ray detectable seals can be easily detected and identified. Therefore, should a fragment of elastomer be identified, it is possible to halt the production line before efficiently removing the contaminated products to prevent them from entering the supply chain. Even pieces that are as small as 2mm can be identified.

Metal/x-ray detectable O-rings and seals can be manufactured in a range of compounds/colours and they all provide a feasible solution to a significant problem.

What Are The Benefits of Metal/x-ray Detectable O-Rings?

First of all, they are extremely easy to detect and that can help to prevent product recall and product loss. Therefore, it prevents the distribution of products that have been contaminated while they can be used in all standard OEM equipment. What’s more, they are also developed for both mechanical, microbial and high-temperature applications.

Axial Seals vs Radial Seals – A Guide

When it comes to seals, there might be a lot to think about, after all, it’s imperative that you get it right and that it works for your application. However, get it wrong and it could prove costly and cause a wide range of problems. Therefore, when it comes to static seals they are categorised as either axial seals or radial seals.

This categorisation is defined by the way in which compression is applied to the cross-section of the O-ring. So, what we aim to do is explain the difference between these two types of seals even though they might seem quite similar. The main difference between radial seals and axial seals essentially comes down to the direction in which compression is applied to the seal cross-sections. In the case of radial seals, compression is applied to the outside diameter and the inside diameter. In contrast to this, axial seals will have compression applied to both the top and the bottom of the cross-section of the seal. So, let’s delve deeper into the different properties and functions of both seals.

Radial Seal – What is it?

It is common to see radial seals used in bore, piston, cap and plug style applications. They then fall into one of two main categories known as dynamic radial seals and static radial seals. Dynamic radial seals are designed to be used in an environment where there is reciprocating, rotating or oscillating movements between two mating components. In contrast to this, static radial seals are traditionally used in those environments where there is very little or no motion between the mating surfaces that are being sealed. It is this specific reason that static seals are then considered to be more forgiving than dynamic seals. They have the ability to manage wider, larger gaps as well as surfaces that have a rough finish and higher pressures.

Axial Seal – What is it?

In applications where axial seals are used the top and bottom of the O-rings cross-section will be squeezed. Therefore, axial seals are the ideal solution for primary seals but also secondary seals in those applications where the primary seal is subjected to a significant amount of fluid or solid contaminants. This kind of seal is commonly used in face or flange type applications and they are a lot easier to manufacture when compared to static radial seals.

How Do You Pick The Right Seal?

As with any application, it is crucial that you choose the right seal. Therefore, it is imperative that you understand the different factors that might determine the seal that you need. It can also be of benefit to obtain professional advice and guidance as this will ensure that you get it right as if you fail to choose the correct seal then you are at risk of experiencing a wide range of problems depending on the industry that the machinery operates in. This highlights how important it is to understand the difference between seals and the benefits they offer.

Selecting O-Rings – Where to begin?

If you have designed a piece of machinery that require seals, you are going to need to determine which seals are right for your chosen application. As a result, you should not overlook the process of designing in the right o-ring within an application.

If you choose the right o-rings, this will commonly help you to meet demands, some of which are often conflicting while they will help to improve performance as well as durability. What’s more, they will also help to reduce the risk of failure, but they are dependent on many different factors and so, we will explore these factors.

Choosing the O-Ring Material

It is vital that the compound material chosen is compatible with the working media that are used within the application. Therefore, if one or more of the following factors are incompatible then it can have a significant impact on the O-ring.

  • The operating fluid can cause the seal material to degrade dues to chemicals. As a result, it can mean that the wrong compound against compatibility could result in the O-ring swelling. This could then lead to a reduction in performance and even the risk of failure.
  • Temperature can also cause problems in the way in which an O-ring performs. Therefore, it is imperative that it remains with the optimum working parameters. If the temperature is too cold then this can reduce the elasticity, causing it to become brittle. This can then cause it to snap. If the temperature is too high then this can cause significant degradation.
  • The operating pressure is also a vital consideration, especially in a static sealing application. Where other factors are taken into account, a material that has a 70 shore hardness will often do but once the pressure increases to 1500 psi, a back up ring should be considered as a way of preventing extrusion. Along with this, it might also be advised to consider a shore hardness of 80-90 to prevent any problems.

Housing Design or Seal Grove

The performance of an O-ring will be determined by the finish of the mating surface but also the seal housing surface finish. This is down to the fact that extremes of smoothness or roughness are not suitable when it comes to creating a good seal. A rough surface, over time, might cause small cuts in the material and that can cause the o-ring to weaken and eventually fail, significantly reducing its lifespan. In contrast to this, a surface that is extremely smooth can cause a similar effect to aquaplane and that can eventually lead to leaks.

As a result, the general rule of thumb or guideline that should be followed is that a seal grove surface finish of 16 rms is suitable for sealing gases while up to 32 rms is considered suitable for fluids. Anything from 8-16rms is considered to be more suitable for dynamic applications as this can help to minimise the risk of abrasion as well as the potential for spiralling.

Seals and Wind Power – Powering the Future

Wind power is one of the most prominent energy sources of the future. As we look to greener alternatives for generating electricity, we are seeing more and more wind turbines being installed across the country. As it stands, there are over 7,000 turbines connected to the national grid in the UK and this is only going to increase. Therefore, wind power is proven to be the most developed alternative energy source.

Oil prices and an increase in the need for more energy has meant that energy suppliers are now looking to take advantage of the wind that blows across the UK. What’s more, as we aim to reduce carbon emissions, energy sources such as wind energy are going to become more prominent.

However, when it comes to seals, what seals are needed to ensure the operation of wind turbines can occur efficiently and effectively.

What Is Needed?

Rotary Seals – These are located in the main gear and it is here where the rotation of the blades is converted into a speed that is considered suitable for the generator. The seals are also used to hold the main shaft in the correct position.

When it comes to maintenance, the main brake will help to stop the turbine to a speed that is critical for maintenance. Here you will find scrapers, wear rings and rod seals while these seals will also be found in the Yaw brake. This break ensures that the nacelle is held in a steady position and facing the wind. All of the brakes, which includes the Yaw brake and the rotor locking system are fitted with critical safety-related functions within the turbine. Therefore, the sealing solutions used within the turbine must offer an enhanced level of reliability and so, they also have to be suitable for the environment which may involve both low and high temperatures.

Piston Seals, Static Seals and Wear Rings – These are all located in the accumulators and these work like hydraulic power batteries to enhance the efficiency of safety and energy. The angle at which the rotor blades face the wind is controlled by the pitch cylinder and actuators. Therefore, seals become an integral part of the system as they will need to withstand millions of strokes. Here you will find not just piston seals, static seals and wear rings but also rod seals and scrapers. These seals work to help control leakages but also improve the service life of the turbine.

The link between the blades and the generator is provided by the transmission. This is a crucial aspect of the turbine and its effectiveness while they are extremely efficient and require very little maintenance. Along with this, radial oil seals are perfect for sealing transmissions and so, they are made of a single lip that is bonded to a metal support using a garter spring although there are other variations to choose from.

So, it is clear to see that seals are a vital part of turbines and how they operate. Without the right seals, they would not work efficiently or effectively.

What is the Ideal O-Ring for Low Temperatures?

It is vital to understand that most elastomers have different formulas that can reduce the working temperature of the compound. In situations where a certain material has been deemed suitable as a result of its chemical compatibility or even its mechanical properties, there could be a version available for low temperatures. Here we give you a range of O-Rings that are ideal for low temperatures.

Why Does an O-Ring Fail at Low Temperatures?

The process of cooling results in rubber losing its elasticity and this is measured as the Compression Set of the elastomer. The compression set is a vital aspect of how an O-ring performs but it is crucial to ensure that a reliable seal is formed. This is defined by the percentage of material that does not return to its original size after it has been compressed.

Low-Temperature Nitrile O-ring

These have a temperature range of -45°C to 120°C.

Nitrile offers a moderate level of resistance against oils, chemicals and greases. However, it is worth noting that at low temperatures Nitrile is prone to shrinking and could lose chemical resistance.

Low-Temperature HNBR O-Ring

These have a temperature range of -45°C to 120°C. Along with this, they also have improved resistance to both chemicals and oils. However, like Nitrile, it can shrink at lower temperatures and lose its resistance to chemicals.

Low-Temperature Silicone O-ring

These come with a range of temperatures. The standard temperature range is -55°C to +200°C. However, the fluorinated temperature range is -60°C to +230°C while the special low temperature compound temperature range is -100°C to +230°C. They come with a high level of resistance to low temperatures although they are prone to wear while they have little chemical compatibility.


Offering a temperature range of -42°C to +220°C, they also come with a high level of chemical resistance although they are considered to be an expensive solution.

FEP/PFA Encapsulated O-rings

These O-rings offer a temperature range of -60°C to +260°C. The elastomer is also suitable for use in a wide range of working conditions.

Astra Seals®

Astra Seals® have a temperature range of -250°C to +260°C. This offers the best low-temperature compression set. However, they are only recommended for use in axial sealing applications with no stretch.

To find out more at the NES Astra Seal®, visit