PVDF joints in High purity water systems 2

[PipingGuy88]

Which type of heat fusion joints are better in PVDF piping systems:
Butt-fusion or Socket-fusion? The goal is to avoid beads and crevices which promote bacteria growth.

Thanks!
Pipingguy

 

[bimr]

Infrared welding uses a non-contact method. IR welding uses the critical welding parameters of heat soak time, change over time, and joining force as found with butt fusion. By avoiding direct contact with the heating element, IR fusion produces a cleaner weld with more repeatable and smaller bead sizes. The end result is a superior weld for high-purity applications.

Infrared is the newest welding method for joining PVDF. In socket, butt, and beadless fusion, the final joint consists of pure PVDF with no other materials present, i.e., solvents, gaskets, or embedded metals. But to complete the actual weld, the polymer must come in contact with metal surfaces to provide a heat sink for melting. Infrared joining uses radiant heat instead of contact welding, eliminating the possibility of contact with non-PVDF substrates during joining. The result is a strong joint with a minimum, uniform bead.