Coaxial valves handle big differential pressures

Edited by the Engineeringtalk editorial team Mar 1, 2004

A new range of 2/2 and 3/2 coaxial valves is designed for demanding media control applications with high viscosity, abrasive or aggressive fluids/gases at operating pressures from vacuum to 40bar.

A new range of 2/2 and 3/2 coaxial valves is designed for demanding media control applications with high viscosity, abrasive or aggressive fluids/gases at operating pressures from vacuum to 40bar.

The ability of the valves to provide fast actuation and long service life under high differential pressures means that they are ideal for use in applications such as industrial furnaces, lubrication circuits, machine-tools, pumping equipment, water treatment, cutting machines and test benches.

Highly robust and extremely compact in design, the coaxial valves overcome the problems of extreme pressure differentials encountered inside valves used at high operating pressures.

In conventional valves excessive actuation forces would be required to overcome these differentials, and the valve user would also suffer from slow and imprecise operation, poor repeatability and reduced operating life.

The design of Asco Joucomatic's coaxial valves solves these problems.

It integrates only one moving part, a stainless steel control tube, which, when actuated, slides seamlessly away from a valve seat allowing the fluid media to flow through the valve uninterrupted.

The major advantage of this design is that pressure remains balanced on both sides of the valve, even with differential pressures of 40bar and fluids having viscosities up to 6000cSt.

At the same time, the valve user benefits from exceptional response times and extended service life: taking the example of a valve with G1/2" connections, the response time is 35ms and the life span is 6 million cycles when operated with water as the controlled medium.

The coaxial valves are available in 2/2 and 3/2 NC and NO configurations and offer a wide range of connection options - G3/8, G1/2, G3/4 and G1in - to suit most applications.

They operate across a pressure range from vacuum (0.0001mbar) to +40bar and a fluid temperature range from -60 to +100C.

Users of the coaxial valves have the choice of stainless-steel bodies for use with aggressive or corrosive fluids, or brass bodies where the fluid medium is nonaggressive but viscous.

Two types of actuation are offered: an IP65 rated solenoid, or a pneumatic operator, the action being direct in both cases.

Complementing the standard configuration coaxial valves is a Namur version, introduced by Asco Joucomatic to appeal to users of process control technology.

This unit integrates a 3/2 or 5/2 Namur spool valve on top of the coaxial valve body.

The Namur valves are available with both monostable and bistable operation and with aluminium, brass and stainless steel bodies.

To ensure operational reliability in difficult environments they have a nonbreathing design, which ensures that all the internal valve components are safeguarded by being completely isolated from the exterior.

This design, and the facility on the Namur valves for pipeable exhaust ports, also guarantees better protection for the working environment and allows the valves to be installed in sensitive areas such as clean rooms, and pharmaceuticals and food processing plants.