Heating, cooling and ventilation systems must have expansion joints designed into the system for three important reasons...

Check valves are found in almost every industrial application acting as non-return or one-way valves. Generally simple devices, check valves perform a vital function preventing reverse flows, damage and ensuring efficient operations.

Properly designed and operating check valves prevent flooding and standing water, control back pressure from wastewater treatment plants and outfalls, and ensure water flows through piping in the correct direction.