Worm Drive Hose Clamp

Lytron frequently receives questions through its “Ask an Engineer” website form. A customer recently asked us the following question: “What is the recommended connection mechanism for heat exchanger tubing with the ‘BD’ designation?”

A beaded (BD) fitting is generally specified when a system requires flexible hoses. The bead prevents the hose from slipping off the cold plate’s or heat exchanger’s tubes while a clamp prevents leaks at the joints. Lytron recommends two types of clamps for the BD fitting: the ear/pinch clamp and the worm/gear clamp.

The pinch clamp is a metal band that is crimped with a special tool. This is the best choice since a pinch clamp can withstand vibration and temperature changes over time without loosening up. Pinch clamps as well as other more sophisticated clamps are available from McMaster-Carr in its “Hose and Tube Clamp” catalog section. The worm clamp consists of a notched band with a screw mechanism to loosen or tighten it. Worm clamps are available at a local hardware or automotive parts store. Lytron’s application note “Fitting and Hose Clamp Selection for Cold Plates and Heat Exchangers” provides more details.

 For OEMs, Lytron can provide custom cold plate or heat exchanger assemblies that include hoses and/or fittings.

 John, Engineer