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Return Flow Impeders

Return Flow Impeders

Our RFI (Return Flow Impeders) are used for applications where the inside of the tube must be kept as dry as possible.
Examples of this are galvanised tubes (to prevent ‘white rust’ formation) and also stainless steel tubes (to avoid coolant in the welding zone). 
Replacement cut-to-length casings and ferrite cores are available from stock. We now also offer RFI impedors with our S300WG casings. This unique white fluoro polymer offers excellent non-stick properties and increases casing temperature endurance by almost 100ºC.RFI impeders have significant advantages over other return flow designs such as:
  • Rugged CNC machined brass internal assemblies
  • Centre tube pinned to end plug avoiding any possible detachment during production
  • High temperature glass casing
  • High temperature O rings
  • NPT tapered thread connections to ensure full leak proof connection
  • No drilled holes or fasteners in casing body

We offer a variety of impeder couplings/supports for return flow impeders

Return flow impeder cooling

Return-flow impeders may offer more resistance to coolant flow than through-flow types, a higher coolant pressure is therefore recommended.  A minimum pressure of 5.5Bar(80Psi)’ensures adequate cooling under most operating conditions. Coolant flow requirements vary widely due to inlet temperature, weld power, frequency and weld area geometry.  Clean filtered coolant is recommended when using return-flow impeders. Since coolant flow can be reduced at lower inlet temperatures, it is beneficial to keep the inlet temperature as low as possible. This may require the use of a heat exchanger or refrigerative cooler when using return-flow impeders. Coolant temperature entering the impeder should be below 20C/70F to ensure optimal performance and lifetime.

Return flow impeders. Available from 9mm to 114mm diameter

Return flow impeders. Available from 9mm to 114mm diameter

Return flow impeders

Easy to replace casings!

Return Flow M4

M-4 Return flow impeders offer the highest performance, working life and seviceability

Return Flow M3

Return flow impeders - Type M-3

Return flow impeders

RF coupling

Return Flow Coupling

Return flow coupling

Return Flow Weld Guard

Return flow impeder with S300WG fluoro polymer coated casing

Return Flow Quarts

A return flow impeder with ceramic fused silica (quartz)

Return flow impeders Type M-4 and M-3

Return flow impeders Type M-4 and M-3

Through Flow Impeders