Position transmitter for critical isolation-valve applications
The HART-enabled Fieldview 4400 valve-position transmitter (photo) is very easy to calibrate, and it incorporates a proven, linkage-less design. As compared to limit switches, it provides much higher reliability, along with valve diagnostics and safety-integrity-level (SIL)-2 capabilities. The position transmitter also includes limit switch outputs, so it can be retrofitted into an existing on/off switch circuit, while also taking advantage of the valve position information. — Emerson, Marshalltown, Iowa