The revolutionary Back Pressure Valve (BPV) has been developed by Wenger to adjust die restriction while the extrusion system is in operation, thus allowing the extruder operator to make on-stream adjustments to the following product parameters:

• Bulk density range +/- 25%
• Size and uniformity of cell structure
• Starch gelatinization
• Shape definition

Operation Mode

The variable opening BPV is mounted on the end of the extruder prior to the final die.  Specific Mechanical Energy (SME) and extrusion pressure are process parameters controlled by valve positioning.

Bypass Mode

An integral part of the BPV is a by-pass feature to divert product from the die when service is performed on the die/knife assemblies and during startup and shutdown.

An option on all new Wenger extruders, the BPV can be retrofitted on most extruders.  Contact Wenger for complete details. 
BPV Brochure (Adobe Acrobat Format)