Generally, hydraulic type seals are considered to be non-metallic, soft rings that are fixed within combination of rings thus creating a seal assembly shape. They may also be captured in groves. Their function is to separate or block fluid in different reciprocating motion applications. These seals do play a crucial role in machinery. They offer fluid power that gets converted into linear motion.
Materials used for construction
Different types of materials can be used to construct hydraulic seals like PTFE, rubber or polyurethane. The material type used in its construction tends to determine the operating conditions. It may even specify the limitations caused by fluid temperature, fluid chemical compatibility, pressure and fluid type. Static hydraulic type seal is present within the groove without any movement. It only seals within a confined space, thereby functioning like a gasket.
Rod seals
They are a vital element found within the cylinder sealing system. These seals are designed to avoid fluid leakage from the hydraulic cylinder to outside. Here, the rod tends to cycle back and forth. They work along with wiper seals with the objective to safeguard the hydraulic system from external contaminants like external weather conditions and dirt. They are also stated to be static seals that are installed within housings or glands. A seal having piston rod is maintained in dynamic motion.
Piston seals
Pneumatic seals or Hydraulic piston seals are designed to ensure various media including fluid is not allowed to by-pass the piston. Here, the piston gets pushed down by the system pressure during pressure cycle. These seals are considered to be dynamic and single acting. Here, pressure acts upon a single side only. They are also double acting seals where pressure is acted upon both sides. Here, choice is rather determined by how the cylinder operates.
Wear rings
Their purpose is to ensure the piston remains centred, thereby allowing even pressure and wear distribution across the seal. Such seals are generally used in rod and piston applications. The popularly used wear ring materials are glass filed PTFE, bronze filled PTFE and Nylon. You can find wear rings in step cut, angle cut and butt cut styles. The best quality ones are durable and also offer amazing choices.
Wiper seals
They are also referred to as Scraper seals. They are used along with various other sealing elements. They help develop tight fit. At the same time, they allow passing of the reciprocating ram rod through the seal’s inner bore. Although it plays a vital role, this seal is perhaps considered to be the most undervalued type when hydraulic cylinder is concerned. These seals are used in various industries and choosing the most appropriate one will be essential for smooth machine operation.
Applications
Pneumatic and Hydraulic type seals tend to cater a wide variety of duty cycles. A few typical applications that are covered are moulding machines, hydraulic presses, mobile cylinders and cylinders. You need to find a good manufacturer or supplier who can offer quality seals for double and single acting cylinders. They should also provide compact seals, symmetrical seals, composite piston seals, static seals, bonded seals and independent wear rings.
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