THE 6815 PRESSURE REGULATING / RELIEF VALVE - What's inside and how it works.

THE 6815 PRESSURE REGULATING / RELIEF VALVE - What's inside and how it works.

Here's a simple sprayer layout using a positive displacement pump. Unlike a centrifugal pump the positive displacement pump draws in a specific volume on its suction or supply side with each revolution and pushes out that volume to the pressure or demand side. Any excess has to go somewhere or else the pump or a pipe will pack up. That's why the PRV - Pressure Relief Valve is in-line to return this excess to the tank via the bypass line.

THE PUMP PUTS OUT A SPECIFIC VOLUME WITH EACH REVOLUTION AND IT'S THE NOZZLE-TIP THAT SETS THE PRESSURE. IT SHOULD BE CLEAR THAT IF THE NOZZLE-TIPS TOTAL VOLUME EXCEEDS THE PUMP'S CAPACITY, THE PRESSURE WILL BE ZERO.

Here's a image showing the innards of the PRV. To the right a spring set, plunger and inlet for the 300 psi or 20 bar unit. The brass inlet illustrated is a 3/4" unit. The seal at the top merely prevents the spray-mix from getting past the adjusting T-screw.

To the left of the image is a spring, stainless steel plunger and hardened stainless steel inlet for the 1200 psi or 80 bar PRV. Note this inlet has 1/2" thread.

As you compress the spring and put increasing tension on the plunger,  more liquid is forced through the nozzles. The excess is forced past the plunger and returned to the tank via the bypass line.

CONTACT chemicon@multispray.com

Tel Intl: +27 83 289 0327 Tel Natl: 083 289 0327