HUOT is a century-old French company that specialises in the manufacture of pipe fittings and components for drinking water supply. The adhesive that the manufacturer had been using to seal its threaded products was causing quality issues, in that once it was cured, it became brittle. As a result, the seal would break if the fitting was accidentally dropped or suffered a relatively minor impact, for example when the fitting was thrown into a steel storage box
In an attempt to solve the problem, the manufacturer trialled several alternative adhesives and found that the WRAS-approved LOCTITE® 2400 thread locker and sealant proved superior for three primary reasons: when cured it could absorb any shock, the resultant bond proved to be durable and, most importantly in this application, it was also hazard-label free.
HUOT manufactures around a million brass pipe fittings a year, and the EN805 standard to which they conform requires them to have a service life of more than 50 years. In reality, this is usually exceeded and the average lifespan of a HUOT product is 70 years. HUOT uses various grades of thread lockers but especially LOCTITE 2400 when medium strength sealing is required as it benefits from the latest health and safety developments. Loctite says that the product provides an effective mechanical connection that is resistant to handling shocks and all installation procedures, creating a durable seal between the body and nipple. LOCTITE 2400 cures when it is confined in the absence of air between the close-fitting metal surfaces when the joint is tightened. As the adhesive fills all gaps between the threads there is no scope for any micromovement of the joint, the major cause of self-loosening. It is designed for locking and sealing threaded fasteners which require normal disassembly with standard hand tools.
Loctite observes that this one-part adhesive was one of the founding products in its parent company Henkel’s Health and Safety range. It remains Henkel’s front line offering for the majority of thread locking applications and has recently been further developed for use on zinc-coated products. In the HUOT application discussed here, a key specification for the replacement thread locker was that it should be hazard label free, and by switching to LOCTITE 2400 the company has significantly reduced customer returns and ensured the long term service quality of products. Discover more here.