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Pneumatic Capacity Control (PACO) for Metering Pumps

AquFlow’s Pneumatic Capacity Control provides remote pump capacity adjustment from a manual loading station and/or in response to an instrument air signal

AquFlow’s Pneumatic Capacity Control permits remote pump capacity adjustment from a manual loading station and/or in response to an instrument air signal from a process controller. The AquFlow pneumatic capacity control is an assembly consisting of three major components,

The Positioner

This is the main part in the pneumatic control, which continuously compares the location of the piston in the pneumatic cylinder with the instrument signal air pressure and regulates the supply air pressure imposed on one side of the piston to obtain the required piston position.

The Pneumatic Cylinder

This with a differential area piston moves the capacity control spool of the pump in response to the signal supplied by the positioned. The cylinder is made of a clear impact resistant plastic, making the position of the piston visible at all times for comparison against a “percent capacity scale”.

The Mounting Flange

This holds the assembly on to the pump, forms the end of the pneumatic cylinder and seals off the ID of the piston to establish a differential area between two sides of the piston.

Positioner Model No.Series of Pump Where Used

Supply Air Requirements

Supply Air RequirementsClean, Dry & Oil-Free

Regulated at 60 PSIG
Pump Capacity Variation Over Instrument Air Range0-100% Rated Capacity.
Minimum Pressure Change Required to Change Capacity.20 PSI or .13% of full pressure.
Repeatable Accuracy of PositionerWithin 1% of full stroke.
Supply Air Consumption0.4 SCFM
Instrument Signal Air Consumption0 SCFM

Instrument Signal Air Requirements

Instrument Signal Air Requirements3-15 PSIG = 0-100%
Failure Of Supply AirMoves to 100% capacity position.
Failure of Control AirMoves to 0% capacity position.
Supply Air Connection1/4” NPT
Instrument Signal Air Connection1/4” NPT

Air Control Station

The optional AquFlow Air Control Station permits manual control of the pneumatic capacity control. The unit includes a 3-way valve for switching from automatic to manual control, a manual adjusting knob and a 3” dial calibrated 0-100% pump capacity with 3-15 PSI auxiliary markings.