QFJ-120C pneumatic marine relay is the additional unit of pneumatic unit combination instrument. It can enlarge the power of communication signal.

Working principle

Pneumatic relay is made up of pneumatic force-balance part and pneumatic power amplifier, for balance , respectively, input and output signals. When the input signal input go into the corrugated pipe, corrugated pipe produce thrust promote bar-Ping, lever around the fulcrum of rotation, change the position of a nozzle tailgate . back pressure of nozzle changes with the change of amplifier’ output, the pressure go into the negative feedback bellows, and then push lever reverse rotation, when the feedback torque and torque measurements are equal

Structure principle

A certain value can be used as a remote control, while a single-needle Indicator (remote control panel is a single needle, Vice-line board is double needle). Is bellows-type body displacement Is amplification as instructed by the four-bar linkage shown in the dynamic operation of the signal. Indicator board, Vice-line to another needle, used to display regulator output signal, another "manual" automatic switch to the work principle of piston body. for automatic / manual switching mechanism. set the value of force-balance device; displacement-type 4 rod measuring amplification mechanism; piston-type switch.