Keystone

Long Lasting Butterfly Valves with a Sturdy Reputation Emerson’s Keystone offers a complete range of butterfly valves from general purpose through to heavy duty and high-performance models. With a tradition of more than 70 years, Keystone built its reputation on providing industrial process butterfly valves known for their reliability, long service life, and reduced operating costs. Independent, third-party life-cycle testing has shown that Keystone resilient-seated butterfly valves last 2.5 times longer than competitors' butterfly valves.