Butterfly Valves

One of the most durable of all resilient-seated butterfly valves in the industry, this valve excels in a wide variety of applications. Cast in both wafer and tapped-lug patterns in a wide variety of material choices, DEMCO butterfly valves feature a one-piece body for minimum weight and maximum strength. The unique stem hole design in the disc ensures a dry stem journal and the hard-backed seat allows ease of installation, reliable operation, and is field-replaceable without special tools. DEMCO butterfly valves are available in sizes 2 in. through 36 in. (50 mm through 900 mm).

Engineered for long-term, maintenance-free performance, DEMCO butterfly valves are commonly selected for a variety of applications spanning a wide range of industries:

Chemical and Petrochemical
Agriculture
Oil and gas drilling production
Food and beverage
Water and waste water
Cooling towers (HVAC)
Power
Mining and materials
Dry bulk handling
Marine and Government

Bi-directional sealing
This valve provides bi-directional sealing at full rated pressure with identical flow from either direction.

Integral flange seal
Molded into the edge of the seat is an integral flange seal which accommodates ASEM weld neck, slip-on, threaded and socket flanges as well as “stub end” type C flanges.

ASME Class 150 rating
Body rating is ASME Class 150 (285 psi non-shock). Wafer body diameters are designed to self-center in ASME Class 150 flange patterns.

Series NE-C
Sizes 2 in. through 12 in. (50 mm through 300 mm), this series is a general purpose valve with neck length designed to provide full clearance of the valve top over two inches of insulation on ASEM Class 150 pipe flanges; available both wafer and lug styles.

Series NE-I
Sizes 2 in. through 12 in. (50 mm through 300 mm), it is suited for a wide range of applications in many industries, including food and beverage utilities and process flow lines. This short neck design is offered in a wide variety of body materials. The valves are designed for installation between ASME Class 125/150 flanges.

Series NE-D Valve
Sizes 2 in. through 12 in. (50 mm through 300 mm), it is a short neck valve with body notches to fit popular lightweight flange patterns, making it ideal for bulk material handling and the transportation industry. Valves will also center in ASME Class 125/150 flanges.

Series NF-C
Sizes 14 in. through 36 in. (350 mm through 900 mm) are available in both wafer and lug styles. The wafer body has two drilled locator lugs at top and bottom for ASME Class 150 flanges. Bronze bearings are installed on both stems for minimum operating torque.