TechArchive

Original article date: July 2000

At last, a valve island that does not result in a compromise on either cost or performance. Tommy Miller takes a closer look

Few people would dispute the benefits to be gained from using valve islands: compact packaging, simplified wiring, and economical to install (compared with wiring and plumbing a multitude of discrete valves). However, it is seldom the case that a machine or item of equipment will be populated with pneumatic actuators that all require the same specification of valve.

In the past this has meant that the machine designer either has to compromise by fitting the valve whose flow rate corresponds to the maximum demanded by any of the actuators or, alternatively, fit valves that suit the majority of actuators but that might restrict the performance of one or more larger actuators. Of course, the designer could opt to fit discrete valves for the larger actuators, but this, as with the over-engineered option, rather defeats the object of using valve islands.

Many manufacturers of valves already give customers a choice of push-in connector sizes, and there is almost always a choice of valve configuration (5/2, 3/2, etc). But, until recently, it had not been possible to mix valve sizes within the valve island. This situation has now changed thanks to the introduction of the Multimach valve island by Metal Work.

Any number of valves from one to 24 can be used within the island, with flow rates for each covering a range of 150 to 800 Nl/min at 6bar, depending on the valve used and the size of the fitting selected; valves come in three sizes with widths of 11 and 14mm, and port diameters of 4, 6 and 8mm.

More user-benefits

But the list of features does not stop there. Electrical connections are made via a 9-pin or 25-pin connector and the valves have been designed to be easy to install and maintain. For example, the push-in fittings, valve-on indicator lights and manual overrides are all readily accessible with the valves in situ. A particularly useful option is for bistable overrides as an alternative to the usual spring-return type – very handy for commissioning and maintenance.

Multimach valve islands use a sandwich configuration, rather than a base of fixed length with add-on valves and blanks. Not only does the Multimach approach save space, but it also saves cost through avoiding the need to purchase an oversize base and a number of blanking units for mid-sized valve islands.

An extensive range of options is available to allow users to configure the islands with, for example, side-facing or rear-facing electrical connections, and air supplies at one end, both ends or with intermediate supplies too. And when it comes to the valves themselves, there are 5/2, 3/2 (normally open and normally closed), and 5/3 valves with closed centres.

• Metal Work

July 2000