Air Volume Tank For Control Valve

Air volume control valves on drain back pump and water systems are one component of a three part system designed to protect well or lake water supply pipes from freezing and to maintain the air charge in a water pressure tank on some submersible pump systems where a bladderless water tank is installed.

Air volume tank for control valve.

Facilities to isolate the volume tank from the air supply and bleed the air upstream of the check valves are also required not only to check that the system works initially but also for future proof testing. As the float rises with the increase in water level the main valve closes trapping the remaining volume of air in the tank. The operating principle of this volume tank is similar with an accumulator on hydraulic. The main function of this volume tank is to reserve the instrument air pressure during the first operation of actuator and use it later.

Typically these systems should be checked at the same time the safety instrumented system sis is proof tested. Volume tank in the shutdown valve application is used to provide a back up in case loss of instrument air supply. All meet asme code section viii for use with air and inert gas pressure vessels.