Certified Control System Technicians (CCSTs) calibrate, document, troubleshoot, and repair/replace instrumentation for systems that measure and control level, temperature, pressure, flow, and other process variables.

CCST question

According to ISA-5.1, the following P&ID symbol represents which kind of device?

A. Pitot tube
B. magnetic flowmeter
C. damper valve
D. constant flow regulator

CCST Answer

The correct answer is D, "constant flow regulator." The symbol for the constant flow regulator is a compound symbol made from the symbol for a variable area flowmeter (FICV) with an integral manual adjusting valve adjacent to a control valve symbol. The line above the two symbols indicates that the valve uses the flow signal to adjust the valve position, and hence, maintain a constant flow rate.

The symbols for the other three items are:

Reference: Goettsche, L.D. (Editor), Maintenance of Instruments and Systems, Second Edition, ISA, 2005.

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