The failure to do routine maintenance on a key gate valve in the Hetch Hetchy water system contributed to the crisis that briefly cut deliveries in half last month, San Francisco's top utility ...

What lurks beneath the surface? What is underneath, where eyes cannot see? Is it something valuable? Is it something old? Is it some treasure or something frightening to behold? These are common ...

Motion-control valves solve troublesome equipment-instability problems. • Overcenter, or motion-control valves, are well suited for load holding and control. • Standard overcenter valves can solve the ...