Aquflow hydraulically-actuated diaphragm metering pumps are by design both rugged and leakproof. However, in some difficult and/or critical chemical feeding applications, it is often desirable to add diaphragm leak detection – whether to protect the pump from hostile chemicals or to protect the process from possible contamination by hydraulic fluid.

For these applications, AquFlow has developed two highly reliable diaphragm leak detection systems. Your NPA sales representative can help you determine which system is best suited for your particular needs.

Series 3000 with PVDF LE 7

Series 3000 Pump w/ PVDF Liquid End and Conductivity Probe

Conductivity-Type Leak Detection

The conductivity-type leak detection system can be furnished on either tubular/disc diaphragm or double disc type diaphragm liquid ends. The system consists of a conductivity probe mounted in the pump intermediate chamber between the diaphragms. This intermediate chamber is filled with process compatible non-conductive fluid.

In the event of a diaphragm failure, process fluid leaking into the intermediate chamber results in a change of conductivity. This change in conductivity of the intermediate fluid increases probe current through the sensing circuit of the solid state control module. When the probe current exceeds the setpoint current, the control module energizes a relay output.


Series 1000 w/ Vacuum-Leak Detection

Vacuum-Type Leak Detection

The vacuum-type leak detection system is a highly reliable means of sensing diaphragm failure, and is frequently used when the process fluid will not allow a conductivity-type system. The vacuum-type system consists of two PTFE diaphragms held together under vacuum and separated by a thin, metallic intermediate ring. In this system, diaphragm failure is detected by sensing a change in vacuum pressure between the two diaphragms.

The complete leak detection system includes a vacuum gauge, tubing, purge valve, vacuum accumulator, and a factory preset vacuum switch. The U.L. listed SPDT vacuum switch is rated 15amp at 125/250/480 VAC, and can be furnished in a NEMA 4 or optional NEMA 7 enclosure. The vacuum switch can be wired to sound an alarm and/or shut-off the pump in the event of a diaphragm failure.