Valves and flow control for water treatment, distribution and sewage infrastructure

Water distribution and treatment systems require valves that remain operable over long service intervals — often without maintenance access for years in buried installations. Resilient-seated butterfly and gate valves dominate large-bore isolation duty because they offer full-bore flow, low operating torque, and predictable shutoff with EPDM or NBR seats that are proven compatible with chlorinated water.

Pumping stations introduce transient pressure events. Check valves sized and selected for the pump curve prevent column separation and surge on pump stop. Air release valves at high points purge entrapped air that would otherwise create pressure spikes and reduce flow capacity.

Wastewater and sludge lines require valves tolerant of solids-laden media. Knife gate valves with elastomer sleeves provide reliable shutoff in slurry service where a conventional gate or butterfly would not seat cleanly.

Gate valves remain the standard for full-bore isolation in water mains where pressure drop at open is critical. Ductile iron GJS-500 bodies with non-rising stems suit buried installations. For large bores (DN300 and above), double-flanged or socket-ended butterfly valves offer a cost and weight advantage while meeting EN 593 and EN 1074-2 performance requirements.

Pressure reducing valves maintain downstream pressure within distribution zones regardless of upstream variation, protecting domestic connections from overpressure. Pressure sustaining valves keep upstream pressure above a minimum to prevent column collapse in rising mains.

Dismantling joints allow valves to be removed for maintenance without cutting the pipe. They are specified at every isolation valve in buried or confined installations. Expansion joints absorb thermal movement and vibration transmission in treatment plant pipework. Y-strainers and basket strainers protect pumps, meters and control valves from debris in both raw and treated water lines.