Ball valve for mixing delivers maximum flow rates

23-Mar-2009 - Last updated on 23-Mar-2009 at 11:44 GMT

Maximum flow rates with minimal pressure drop via a full port design are delivered through the new series 3BV2 automated ball valve by Australian firm WE Anderson, a division of control and instrumentation company Dwyer Instruments.

"The ball valves are perfect for mixing in a variety of applications," said the company.

Further, the firm added that the ball valves, that come with a choice of either pneumatic or electric actuators, "feature a blow out proof stem and reinforced RTFE seats and seals for added safety, longer life and leak free operation".

Choosing the actuator

An actuator is a mechanical device for moving or controlling a mechanism or a system. According to the Australian firm, the double acting pneumatic actuator in its system uses an air supply to drive each of the actuator ports.

The spring return pneumatic actuators use an air supply to drive the valve stem in one direction and an internally loaded spring to return to the valve to its original position.

"These actuators are constructed of anodised aluminium and are epoxy coated for years of service," added the process control firm.

Epoxy, or polyepoxide, is a thermosetting epoxide polymer that is a potent electrical insulator, protecting electrical components from short circuiting, dust and moisture. Most common epoxy resins are produced from a reaction between epichlorohydrin and bisphenol-A.

WE Anderson states that its electrically actuated models have NEMA 4 enclosures with "an optional explosive-proof, NEMA 7, enclosure". The electric actuators are available in either 'two position' or proportional control with a standard 115V AC supply.

For industrial process control instruments, analog 4-20 mA and 10-50 mA current loops are commonly used for analog signalling, with 4 mA representing the lowest end of the range and 20 mA the highest.

Such instruments can be used to measure flow, or other process variables. WE Anderson states that its modulating actuator accepts 4mA to 20 mA input for variable valve positioning while the two position actuators uses the 115V AC input to position the valve open or closed.

The electric actuator features include thermal load protection to "withstand stall conditions, visual position indication and permanently lubricated gear train".