Both pneumatics and hydraulics are applications of fluid power. The main difference between these two systems is the medium used to transmit power.
In Hydraulics, liquid / oil is used to transmit power, whereas in pneumatic applications, compressed gas (generally air) is used to transmit power. Most industrial pneumatic applications use pressures of about 80 to 100 psi. Hydraulics applications commonly use from 1,000 to 5,000 psi but specialised applications may exceed 10,000 psi.
What are Hydraulics?
Hydraulics work on the principle of pressurised fluid forcing mechanical action. A hydraulic system installed on a machine is called a hydraulic circuit. These are composed of a pump to compress the fluid, lines to carry the fluid, a cylinder where the fluid is pumped and a piston moved by the pressurised fluid in the cylinder. Hydraulics can also actuate shafts to power hydraulic motors and conveyors. all types of hydraulic, and similar, equipment.
What are Pneumatics?
Pneumatics are similar to hydraulics but instead of fluid, pneumatics use gas (usually air). Air is pulled into a compressor and is then forced through lines to different tools. The compressed air actuates pistons and shafts and forces them to move. Pneumatics are often used for different kinds of hand tools and also for machines doing repetitive motion. A jackhammer is a good example of a repetitive pneumatic tool.
Hydraulic seals are generally non-metallic rings fitted in a groove or fixed in a combination of rings, forming a seal assembly, to block or separate fluid in reciprocating motion applications. Hydraulic seals are vital in machinery and their use is critical in providing a way for fluid power to be converted to linear motion.
They can be made from a variety of materials such as rubber, polyurethane, or PTFE. The type of material is determined by the specific operating conditions or limits due to fluid type, pressure, fluid chemical compatibility or temperature.
A static hydraulic seal is located in a groove and sees no movement – only sealing within its confined space, acting like gasket.
There are many types of hydraulic and pneumatic seals :-
A Rod seal is a dynamic seal exposed to movement on its inner diameter along the shaft or rod of a hydraulic cylinder. It seals around the reciprocating rod (or ram), preventing leakage of fluid from within the cylinder to the outside.
A Piston seal is a dynamic hydraulic seal exposed to movement on its outer diameter along the tube or bore of a hydraulic cylinder. It seals between the reciprocating piston and cylinder bore. Piston Seals (also known as Piston Rings) are used in hydraulic cylinders for fluid sealing.
Our Hydraulic & Pneumatic range caters for the full range of duty cycles. Typical applications include; cylinders, mobile cylinders, hydraulic presses and moulding machines.
Part of UK Seals’ Hydraulic range includes telescopic seals. Please click here to read about our telescopic seals.
UK Seals range of hydraulic and pneumatic sealing products are designed to give optimum properties including, ultra long life, ultra low friction, water resistant and wide temperature capability.
To find out more, or to discuss your application, please contact our Technical Sales team. Give us a call on +44 (0)1388 722817 or send us an email to firstname.lastname@example.org.