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Everything you need to know about Pneumatic Valves

August 15, 2013 | written by twg

Pneumatic valves are used to create precise, pressurized airflow in order to ensure that the systems which they operate in operate at peak performance. Today’s post will gives you an introduction to the four main types of Pneumatic valves and their practical applications. Diffley/Wright carries all four styles, including Poppet Valves, Diaphragm/Poppet Valves, Spoppet Valves and Spool Valves. As a supplier of Humphrey valves, you’ll be pleased to know that we offer all four!

Poppet Valves

Poppet Valves allow for high flow and positive shut-off operation for a wide range of industrial needs. Constructed entirely out of non-corrosive materials, Poppet Valves can be used with a variety of liquids and gasses where quick control is necessary. In most applications, a pressure differential helps to seal the valve and when used in other, more specific applications – they can be opened, too.

Diaphragm-Poppet Valves

Diaphragm-Poppet Valves expand upon the design of a Poppet valve, simply by including a diaphragm. The major similarity is that – like Poppet Valves – the design is unbalanced, which means that you’ll receive the same assurance of return to a given position. The difference is that the diaphragm increases durability – especially when with a different or non-lubricated media. The other advantage is that variety of durameter and diaphragm compounds make it easy to modify valves based on the environmental or application operating requirements.

Whenever you use a Diaphragm-Poppet Valve, you’ll be pleased to know that you’ll experience an extremely low leak rate thanks to the valve’s strong sealing control. They also come in a number of configurations, including 2-way, 3-way and 4-way valves, making them easy to fit into a variety of situations.

Spoppet Valves

Spoppet valve design is heavily based on poppet and spool valve design – as it emulates their characteristics by providing a blend of primary poppet sealing and minimal sliding seals. While the Spoppet Valve does retain some unbalanced characteristics – it mostly evens itself out with balance of pressure to reduce actuation forces. With only one sliding seal engaged at a tie, there’s far less drag within the valve body, itself.

Overall, Spoppet Valves serve as an excellent bridge or space filler between regular poppet and spool valves. That’s an important space, too – because it makes them more usable than most – as they can be used in a wide number of critical situations. By blending multiple designs, Spoppet valves are one of the most cost efficient 3 and 4-way valves available today, and can survive virtually any conditions.

Spool Valves

There are three primary forms of Spool Valves: Lapped Shear-design with no seals, Dynamic seals, or O-ring. Spools are generally more specialized in use, as they’re far more effective when manufacturing for 4-way valves and far less adaptable for 2 or 3 way configurations. The good news is that Spool Valves can be deployed in a variety of functions depending on the desired position control required. Lapped/Shear design spools operate without lubrication, but are less tolerant to variations in lubrication or by-products of compressing air at the air compressor. Conversely, Dynamic seal spool valves generally require hidden lubrication. That being said, Lapped spool valves have a high leak rate that might not be deemed appropriate.