Pressure Relief Valve Operation
The following information relates to The Pro Built Melters and the Nordson 2000 / 3000 Series Melters with 14:1 and 21:1 pumps.
A FAULTY PRESSURE RELIEF VALVE CAN RENDER A HOTMELT UNIT UNSAFE.
The pressure relief valve is an important part of safe operation of the melter. The operator’s manual states a pressure relief in good working order will relieve pressure at 1200 psi.
Cold adhesive expands when heated. Under certain conditions, this expansion can cause manifold pressures in excess of 2000 psi.
A pressure relief valve is fitted to the hydraulic circuit of the glue unit. Once the pressure of the hydraulic system exceeds 1200 psi under normal conditions, the pressure relief valve vents this pressure back to tank
The standard 14 : 1 pump can obtain a pressure of 1400 psi at 100 pound air pressure.
Pressure relief valves require servicing on an annual basis to ensure correct operation. On site adjustment carries inherent risks and should not be attempted.
Crafers Engineering has specialized equipment to service, test and set the Pressure Relief Valve.
A pressure relief valve relieving under the standard set pressure can cause process problems.
A charred or dysfunctional Pressure Relief Valve will not allow high manifold pressure or hose pressure to vent, putting personnel at risk.