Hydraulic & Pneumatic Seals
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Rod Seals are used to maintain and regulate any kind of fluids or air that are present when the cylinder is in motion. A rod seal functions by the media applying pressure to the back of the seal, energizing the sealing lip forming a seal against the shaft. Meaning that the seal will prevent any kind of leakage or corrosion on the cylinder or other parts of the unit.
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Rod Seals come in many different kinds of styles, some of theses styles being:
Grooved Rod Seals - Also known as a U-seal, This is a single acting seal, generally made from Polyurethane (PUR) or Nitrile (NBR) depending on application. They can come with Backup rings (Anti extrusion rings) for higher pressure applications, or with O-rings which keep the seal energized to prevent weeping when there is low pressure.
Rod Composite Seals - Predominantly constructed from Bronze PTFE, which is energized with an O-Ring. The PTFE will provide a low friction, non-stick/non-slip hard wearing seal. Also good in high pressure applications.
Rotary Rod Seals - A PTFE grooved face, energized with an O-ring These are simply used to create a seal on the rotating shaft of the unit.
Rubber & Fabric Seals - Created by rubber impregnated with cotton fabric, These are used in all types of light hydraulic and low frequency use applications. They can come with a backup ring on the internal diameter to enhance the pressure rating of the seal. Interchangeable with a U-seal.
T-Seals - This seal will have Backup Rings on either side of the seal to help stop the seal from extruding while under pressure.
Chevron (Vee-Packing) Seals - This seal is made up of multiple chevron pieces, or Vees, that are packed together, usually in packs of three or five. You will find this seal in more medium or heavy duty applications.
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Material requirements will depend on the application of the Rod Seal. For hydraulic systems you will find polyurethane (PUR) the most common, along with fabric and rubber single actors. Pneumatic systems will predominantly use an elastomer such as Nitrile (NBR) or Fluorocarbon (Viton/FKM). Other materials available for both Hydraulic and Pneumatic systems include other elastomers such as EPDM and Silicone as well as PTFE’s in various grades, Virgin PTFE, Bronze filled PTFE and Carbon filled PTFE’s. Please contact our sales team to discuss your requirements.
See our Hydraulic & Pneumatic Wiper Seal profiles
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Wipers are seals that are fitted so that the ram rod can pass through with the seal scraping off any kind of dirt or moisture as the piston rod retracts.
Wiper Seals are also known as wiper scraper seals or scraper seals.
A Wiper Seal is used to make sure that no debris, dust or moisture can enter the gland housing of a ram. Any kind of foreign objects or liquids that get into the gland housing could cause serious and expensive damage to any other seals that are fitted on the ram. As well as the rod and cylinder.
Wiper Seals are usually used on hydraulic and pneumatic cylinders, however they can also be used on bicycles, motorcycles and telescopic suspension forks.
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Wipers can come in a variety of different styles. There are the standard flexible wipers, these are usually made from polyurethane, however we are also able to manufacture them in materials such as rubber, silicone and PTFE.
Wiper Seals can also come with a either a metal casing or a PTFE casing. There are also wiper designs that use a harder material, such as Bronze PTFE, with an o-ring preload.
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The most important thing to consider when choosing the material of the wiper is the environment that it will be in and the type of Wiper Seal you will need.
The most common material used for Wiper Seals is Polyurethane, which can them come with a PTFE casing for extra strength. To decide which material you will need, you will have to take into account the temperature it’ll be working at and the pressure that is going to be applied to the Seal while it is in use.
Please feel free to contact our team if you require any guidance with choosing the best material for your job.
See our Hydraulic & Pneumatic Piston Seal profiles
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Piston Seals will be used in hydraulic cylinders for fluid sealing and pneumatic cylinders for air sealing This is to stop any fluid or air from by-passing the piston as it is being pushed down the cylinder during the pressure cycle.
The fluid or air will generate high pressure on the Piston Seal, this will increase the contact forces between the Piston Seal and the surface of the cylinder.
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The two most common types of Piston Seals are Single-Acting and Double-Acting.
Single-Acting - This type of Piston Seal will only hold the pressure on one side of the piston, this is because it only has one sealing lip that will be in contact with either the cylinder wall or bore. Pressure will be retained from the direction of the sealing lip, this will then move the piston through the cylinder.
Double-Acting - This type of Piston Seal will hold the pressure from both sides of the piston. This is because of the two sealing lips, one for each side of the piston head. Double-Acting piston seals will allow maximum mechanical effort to allow movement of the piston through the cylinder.
Both styles can be used with separate or integrated Back-up Rings and Guide Rings.
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Like with all seals the choice of material is dependent on a variety of factors. You should take into account the style of Piston Seal you will require, the pressure the seal will be under, the friction losses that could occur as well as if the piston head is integral or split.
Most common materials used for Piston Seals are Nitrile rubber (NBR), Viton, EPDM, Thermoplastic Polyurethane (H-PU), Polytetrafluorethylene (PTFE) and Acetal.