One area that’s changing is the techniques valve operators use to recognize valve positioning, says Ed Hardin, owner of Hardin Consultants in Charlotte, N.C. “It’s not enough to expect a valve to open or close. You need to know whether the open or close happened. According to Murphy’s Law, the most critical valve will have a problem of indicated position most frequently.”
“Too often the indicator is a direct-action micro switch, which is subject to physical change or damage causing loss of reliability,” Hardin explains. “Secondary operator devices often can resolve this problem but introduce secondary reliability concerns. Visual or light transmission devices can mitigate some of these concerns, but then protection from blockage, dirt, trash and alternate sources become critical.”
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