Metachem Corporation also manufactures Hydraulic Diaphragm Metering/Dosing Pump with Automatic Stroke Controller. This model comprises of hydraulically actuated diaphragm Liquid Heads incorporating Diaphragm Actuated Replenishing system along with an Actuator and Controller. The working principle of this pump is identical to the Hydraulic Diaphragm Metering pump. The only difference is that an Electrical Actuator is mounted on the top of the pump. With the help of this Actuator and the Stroke controller the stroke length of the pump can be controlled automatically with the help of an Input signal of 4- 20mA.

Working Principle
An Electrical Actuator is a device, which converts electrical energy derived from motor to corresponding mechanical movement which is imparted on final control element. Each Electrical Actuator is provided with Hand wheel with clutch for manual operation in case of power failure. A continuous local mechanical position indicator is provided which shows real time opening/closing of Actuator irrespective of whether Actuator is in manual or electrical mode. These Actuators work with an Input signal of 4-20mA. Normally 4mA output signal corresponds to Fully close i.e. 0% stroke length of pump condition and 20mA corresponds to fully open condition i.e.100% stroke length of pump. A feedback Potentiometer fitted inside the Actuator converts the mechanical movement of Actuator to corresponding resistive output. A two wire Position Transmitter PPT 200 converts resistive output of Actuator mounted feedback potentiometer to corresponding 4mA to 20mA current output. A positioner unit which also acts as a comparator, compares input signal of 4mA to 20mA based on process parameters, with feedback signal of (4- 20)mA generated from Actuator mounted PPT 200 and generates open/close relay signal through IC’s which is routed through RC network for forward and reverse movement of motor until the desired position is achieved. The Actuator which is mounted on the pump with its change in linear motion due to the input signal given, in turn changes the stroke length of the pump due to which we get the desired flow.


Material of Construction of Wetted Parts
1. AlSl 304SS / AlSl 316SS / ALLOY2O / HASTELLOY B,C / PP / PTFE /PVC

Salient Feature
Pump performance in accordance with API 675
Leak less Pump
Low maintenance & accuracy for longer period
Used for pumping toxic / hazardous chemicals
Can pump wide range of liquid
Built in safety feature

GENERAL SPECIFICATION
Max. Flow rate: Up to 3728 L/Hr.
Max. Pressure: Upto 150 Kg/cm2