Wenger - Model BPV -Back Pressure Valve

Use during Start-Up/Shut-down:

• Divert extrudate to waste  (bottom discharge)
• Eliminates wet material in knife hood or conveying system
• Cleaner work environment during start-up
• Safer work environment for shut-down and die removal

Use during Operation

• Regulate extruder barrel pressure
• Provide relief of die pressure as needed (bottom discharge)
• SME input
• Can help adjust for variations in material

The BPV provides a vital "KILL STEP" by diverting extrudate that has not reached the CCP temperature.
Wenger systems use precision sensors in the extruder barrel that relay extrudate temperature to the control system in real time.  If at any point during a production run the extrudate temperature is below the Critical Control Point (CCP) temperature, the BPV will alert the operator and switch to "discharge" mode, preventing the extrudate from entering the die. Operators can then make necessary adjustments to reach proper temperature and the BPV will return to normal operating mode (full flow to the die).