Silicone Calibration Hose From Fenner Precision

Silicone Calibration Hose from Fenner Precision


A leading pipe rehabilitation contractor approached Fenner Precision to develop and manufacture a reusable, non-stick, expansion bladder that could be employed as part of their trenchless CIPP renewal system for sewer pipes.


To assist the development of a suitable product, Fenner Precision engineers worked closely with the contractor to understand all aspects of the system and application, in order to ascertain a comprehensive list of the customer’s project requirements.

During discussions it was learnt that the chosen cure system for the resin impregnated felt liners was going to be hot water, therefore bladders would be required that would not prematurely heat age while also allowing heat to transfer well.

Using their extensive knowledge of fabrics and elastomers, our engineers developed a silicone coated knitted polyester calibration hose which would be easy to deploy and achieved the required level of flexibility and expansion, while also providing the necessary temperature, wear and release properties for its particular application.


Since they were first developed over 35 years ago, Fenner Precision’s silicone calibration hoses have been used in no-dig CIPP rehabilitation technology systems globally and have become a key product at our manufacturing site in Lincoln, UK.

The choice of materials makes the calibration hoses suitable for hot water curing systems, but also ideal for the higher temperatures reached when steam curing. Their flexibility and expansion enables them to conform to the required pipe size at the necessary pressures, meaning the liner gets fitted snugly to the host pipe. They are a proven cost effective solution, they can be reused many times over thanks to the chemical resistance, wear and release properties offered by silicone.

Fenner Precision’s silicone calibration hoses / expansion bladders can be produced to fit pipes from 3” – 39“ (75mm to 1000mm) diameter and can withstand temperatures from
-40ºC to up to 200ºC.

Fenner Precision – designed to fit your needs. Exactly.


Call or email us today to speak to one of our experienced and knowledgeable team members.