Prime Verification

Having a primed pump is great, but how can you know when a pump is primed and it’s safe to start?  How would you know if a pump lost its prime?  To answer these questions, Q-VAC priming valves are typically installed with a proof-of-prime level switch kit (sometimes referred to as a “pump protector”) to signal when a pump is primed or to provide A warning that prime has been lost.  This signal is connected to the SCADA system, pump motor controller, an alarm, or to a prime status panel.

In most applications, our UL listed float-type level switch provides reliable performance and value.  This switch is normally supplied with brass pipe fittings and SPDT contacts, but DPDT contacts and 316SS pipe fittings can be provided.  CSA approved versions are also available.

For applications with aggressive or coating liquids, or for high flow applications, we recommend using our UL / cUL listed severe duty capacitive type level switch kit. This level switch has no moving parts and uses only 316ss and Kynar wetted components for the ultimate in dependability and liquid compatibility.  Other features include a NEMA 4X junction box, adjustable time delay setting, and LED indicator light.

Regardless of the switch type, one proof-of-prime switch is recommended for each pump being primed.

Priming Valve and Proof of Prime