Model G 3-way Rotary Control Valve

The AMOT Model G 3-way rotary control valve (Models GEF, GPD, GG) provides a high degree of accuracy for precise temperature control in mixing and diverting applications. If you experience long warm-up times, excessive white smoke coming from the exhaust, or difficulty regulating fluid temperatures at idle, replace your thermostatic valve with an externally actuated AMOT Model G control valve without the need for piping modifications.

AMOT G valves are 3-way control valves consisting of a heavy-duty rotary valve and either a quarter turn electric or pneumatic actuator. The valves provide a high degree of accuracy and repeatability for accurate temperature control and are equally precise in mixing or diverting service over a wide flow range.

The heavy-duty rotor design provides tight temperature control without high maintenance requirements. The system is available in three standard control configurations: electric, pneumatic, and electro-pneumatic, offering flexibility for most needs. Designed for high vibration service, the AMOT G valves are qualified to Lloyd’s Marine Requirements for shipboard service. Valves can be directly mounted to reciprocating machineries, such as diesel engines, without vibration isolation. The heavy-duty actuators are specially reinforced to provide vibration resistance.

The standard valves are suitable for various fluids such as water, water/glycol, seawater, lubricating and hydraulic oils. Optional body materials are available for services involving synthetic or fire-resistant oils, deionized water and ammonia or freon in oil.

Electric

For the electric valve, the actuator of the G valve assembly uses an electric motor that rotates in either direction in response to the ON-OFF signals received. The motor drives a gearbox connected to the rotor shaft and turns the valve rotor clockwise or counter-clockwise, a maximum of 90 degrees. At the end of travel, limit switches are incorporated to isolate the electrical supply to the motor when the valve rotor has reached either end of the rotation. A feedback potentiometer is standard and provides position indication to the control system. The actuator is powered by an electric motor driving a worm-type gearbox. The worm gearbox prevents reverse drive due to fluid forces. It is fitted with manual override as standard, enabling valve operation without power.

Pneumatic

The pneumatic valve uses a spring return pneumatic actuator and positioner to control the rotation of the valve in response to an input signal from a pneumatic or electro-pneumatic control system. The pneumatic control system sends a pneumatic signal ranging from 3 to 15 psi to the actuator to position the valve at the desired temperature setting correctly. The pneumatic control system usually consists of a P+I pneumatic controller, sensor and the necessary air supply conditioning equipment (regulators, filters and water traps). The actuator is fitted with spring return as standard, allowing fail-safe configuration if necessary. It is also equipped with a valve positioner enabling accurate and repeatable movement.

Electro-Pneumatic

The electro-pneumatic valve system combines electric and pneumatic technology, consisting of a pneumatically actuated three-way control valve with an electro-pneumatic converter, type 8064A. The probe sends a resistance signal to the electronic controller, sending a 4 to 20mA signal to an I/P converter that converts this to a pneumatic signal. The electro-pneumatic system combines the features and functionality of the AMOT electronic control system with the fail-safe action benefits of a pneumatically actuated valve.