Bypass valves

Bypass valves or pressure relief valves are metallic sealing valve systems specially designed for the diversion of a polymer melt flow. These valves come as a separate unit and can be installed on the main extruder side as well as on the co-extruder side of the crosshead. In case of maintenance works, conductor breaks or simply a tool change the melt flow can be easily diverted in order to facilitate the handling of the crosshead and to avoid a stop of the extruder. A wide range of working diameters and casing sizes are manufactured according to your need. The UNITEK bypass systems are available with manual, hydraulic or pneumatic actuation. In case of a hydraulic or pneumatic system, it is possible to fully integrate it into a new or existing line control - ideal for the retrofit of your extrusion line.

Unitek - Bypass systems
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UNITEK - bypass systems
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Bypass valves with rotating pistons

Bypass valves with axially displaced piston


Flow channel diameter:
(8) / 10 / 15 / 20 / 25 / 30 / (50)mm
(0.314″) / 0.393″ / 0.590″ / 0.787″/ 0.984″ / 1.181″ / (1.196″)



Manually actuated bypass valves with rotating pistons

Hydraulically operated bypass valves with axially displaced piston

Pneumatic drives for upgrade