For pipe diameters up to 6 5/8”(168.3mm)’ you can use standard through flow impeders with single large ferrites or multiple pieces.
A cost effective alternative as pipe diameters increase is an impeder cluster assembly. This consists of a number of individual impeders assembled together into a common manifold which feeds coolant to the impeders. These impeders can be standard round through flow or rectangular configuration and have quick release fittings. Cluster assemblies consist of an aluminium manifold with a clamping system. Also included is a spacer plate to maintain correct alignment of the impeders. Coolant connections are flexible hoses or copper tubing. Return-flow cluster assemblies are available as an option.
EHE Consumables rectangular modular impeder clusters can be utilised for larger diameter pipe ranges. The photo below shows a 14-impeder manifold for 660mm x 25mm wall thickness API pipe. In normal operating conditions the top impeder would require periodic replacement, this impeder can be supplied as exposed ferrite design(as shown) or with a ceramic heat protection pad to increase lifetime.