About Twisted Tape

History

A twisted tape is a well-established and simple technology used since the 19th Century, a flat piece of metal or strip, twisted to obtain a regular pattern.

In order to design and use twisted tapes, a few variables have to be considered when these enhancement devices are specified.

The width of the twisted tape must be less than the tube inside diameter, with the thickness and the twist ratio being inter-dependant correlations that have to be specified at design phase. Design data and correlations are widely available in the public domain, but much of this information is considered to be old and specific to certain flow regimes. The modern research has looked into modifications of tapes and the issues of fitting inside a tube or more advanced studies on flow pattern in 2-phase applications.

Correlations

The universal and comprehensive used correlations were studied by Manglik and Bergles, as they cover both laminar and turbulent flow and have been widely accepted and adopted as the basis for most of the heat transfer software calculation methods. Some of these corelations use a Reynolds number based on the equivalent tube diameter and others use the hydraulic diameter.

Large variety of raw materials available

A large variety of high-quality raw materials are stocked at CALGAVIN’s headquarters in Alcester, United Kingdom. From carbon steel, through to stainless steels or higher grades such as pure Nickel, Tantalum, Zirconium or Titanium – all ready to meet your requirements.

We can also cut any raw material to shape, using our state-of-the art laser cutting machine down to any specification. Let us know your material preference, exotic grades are our specialty.

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Turbulator

How a Twisted Tape type turbulator works

A typical twisted tape geometry divides the flow within the tube in two, creating a spiral flow path.

This action increases the tube wall velocity, but there are secondary flows (and natural convection) involved which CALGAVIN has studied using CFD and extensive R&D testing, by inducing a swirl flow where its intensity is purely defined by the interaction between fluid viscosity, convective inertia and centrifugal forces.

Typical heat exchanger designs using twisted tape type turbulators as a tube side heat transfer coefficient enhancement device, would reflect transitional and turbulent flow regime applications, but not necessarily restricted to these flow regime areas.

Performance GuaranteePerformance correlations are available in the public domain and not owned by CALGAVIN, since further testing across a specific flow regime is necessary for reliable correlations. For this reason a thermal guarantee is not usually provided for twisted tape enhancing devices, but we do however offer a thermal guarantee for other tubeside enhancement technologies. For more information visit calgavin.com

Quick Twisted Tape
Specification Check

Use our Twisted Tape specification tool to check the manufacturing feasibility of your twisted tapes.

Please use this function to input your twisted tape or tube specification details, in order for us to confirm if we can produce to your spec requirements.