Proper material selection is the key to expansion joint reliabilityJune 16, 2017 REDWIRE is news you can use from leading suppliers. Powered by FRASERS.
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NISCO (Northern Industrial Supply Co.) is proud to offer expansion joints from HOLZ Rubber Company. Though these joints have earned a reputation for their high quality, successful operation goes beyond quality. Each expansion joint must be manufactured to meet the needs of the application to get the best results. Selection of proper material — one that can stand up to the demands of the application — is a critical component for longevity and effectiveness.
Lower cost materials don’t always equal savings
A PVC plant had a suction leak on one of its boiler blower’s air inlet expansion joints. The leak was created when the expansion joint was pulled into the duct stream and ripped as a result of rubbing against the ductwork. The reason the expansion joint failed comes down to one factor: it was constructed from non-laminated Teflon, which was the wrong material to use in this situation. This is because a boiler blower air inlet operates under negative pressure and, therefore, requires a strong material. Non-laminated Teflon collapses under vacuum and punctures easily because it is very thin. Though this cheaper material seemed like the most economical solution at the time, the tear caused cold air to leak into the boiler blower, which dramatically reduced the efficiency of the boiler, costing the operator money.
For this application, Viton is a better material option because of its rigged strength. Under a negative pressure situation, the Viton expansion joint won’t be pulled into the ducting system because of its strength. HOLZ Rubber Company provided a ⅛-inch Viton expansion joint with fibreglass reinforcement. The expansion joint was secured in place using Viton caulking with band clamps. Although a more expensive option at first, the Viton expansion joint is reliable and has a long service life, which results in savings for the customer.