Durability and Resistance

Flexseal couplings are manufactured for use in connecting pipes in sewerage, drainage, plumbing and non pressure applications. They consist of an elastomeric sleeve (EPDM) with clamping bands produced from stainless steel. The product is manufactured to the BS EN 295 Standard which has a requirement for the rubber to be compliant with BS EN 681 Part 1.

There are three aspects that relate to the durability of the product:

• The life of the elastomeric sleeve
• The life of the stainless steel clamp bands
• The product performance

1. The durability of elastomers is dependent upon 'ageing' of the rubber. The ageing process is influenced by many factors such as the type of elastomer, the temperature and the environment in which the elastomer is functioning. EPDM has a good or excellent resistance to oxidation, ozone, ultra violet light and heat.

2. Stainless steel usually has excellent durability. It can be attacked by chloride ions (salt) present in soils by the mechanism of crevice corrosion. If this is anticipated to be a problem then grade 1.4401 (316) stainless steel should be used. Additional protection is required for tidal and seawater applications e.g. water resistant tape.

3. The performance of the Flexseal product is dependent upon maintaining contact pressure under the clamp band to ensure the seal remains tight. Flexseal clamp bands can exert sufficient clamping pressure at the recommended tightening torque to ensure that there is adequate contact pressure even after 50 years of stress relaxation.

The content of the drain or sewer and also the temperature of operation can also influence the life of the product. Flexseal products are suitable for normal drain or sewer operation at a continuous temperature of no more than 80 degreeC. Flexseal are confident that all products will have a minimum design life of 100 years if correctly specified and installed.