Model 22 control valves from OCV Control Valves have rectangular-shaped, soft-seat seals that provide a drip-tight Class VI closure. Their throttling seat retainers create flow and pressure stability, preventing water loss and system-damaging surges. They allow supply facilities to vary pressures and/or flow based on external factors, such as time of day. They are registered to ISO 9001 and are certified to the most comprehensive NSF/ANSI 61 listing in the automatic control valve industry. 918/627-1942; www.controlvalves.com.