Thursday, July 24, 2014

Tips and Considerations When Applying Control Valves

DeZurik Control Valve
Misapplying or choosing the wrong control valve for an application can have serious consequences on a  plant’s operation and productivity. Here is a list of things to consider when applying control valves.

Control valves are not intended for isolating a process and should not be used as such. They are not intended to provide a bubble tight shutoff.

Choose the proper body, seat and wetted materials for the process being controlled. Consider material compatibility, pressure ratings, and operating temperatures prior to valve selection.

When designing your control loop, put the flow sensor upstream of the control valve. Putting the flow sensor downstream of control valve exposes it to possible bubbles caused by the flashing and turbulence of the flow in the valve cavity.

Thursday, July 3, 2014

Watch a Large Scotch Yoke Pneumatic Actuator Operate

I you haven't seen a large scotch yoke actuator operate, the watch the video below of a ROTEX DRS high performance scotch yoke pneumatic actuator mounted on a large ball valve.

The video shows actuator opening valve, closing valve, the valve position indicator, the hydraulic manual override and manual hydraulic pump.  This is a nice visual education for anyone who never saw a large valve and a large actuator operate.