You are here:


High Performance Butterfly Valve


Size Range

NPS 2 to 66 / DN 50 to 1500

Temperature Range

-62°F to 500°F (-52°C to 260°C)

Maximum Allowable Operating Pressure

Series 40/41 ASME Class 150
Series 42/43 ASME Class 300
Series 44/45 ASME Class 600
Series 4A/4B ASME Class 150/300
EN 1092 PN 10, 16, 25, 40, 63, 100

Shutoff Rating

Zero Leakage

Body Style

Wafer, Lug, Double Flanged

Flange Drilling

ASME B16.5, EN 1092

Fugitive Emissions Standard

ISO 15848-1, API 641

Body Materials

Carbon Steel, Stainless Steel, Nickel Aluminum Bronze

Stem Materials

Stainless Steel

Seat Materials

RTFE with Resilient Energizer, PTFE with Resilient Energizer
Fire Safe: RTFE and Inconel® with Resilient Energizer

Disc Materials

Stainless Steel, Nickel Aluminum Bronze

Design Standard


Features & Benefits

High Pressure, High Temperature, Zero Leakage Butterfly Valves

The McCannalok high performance butterfly valve (also known as a double offset butterfly valve) features an innovative design that offers rugged reliability and extremely easy maintenance in the field. Independent and internal tests prove the Series McCannalok valve’s superior service life capability, with zero leakage shutoff.

The McCannalok valve’s unique, patented design received Chemical Processing’s Vaaler Award for Best Product shortly after it was introduced. The simple, innovative design offers rugged reliability and extremely easy maintenance in the field.

Independent and internal tests have proven superior service life capability with zero leakage shutoff through over 100,000 cycles. Series 40 Bray/McCannalok valves can be automated inexpensively with any of Bray’s pneumatic and electric actuators. The McCannalok high performance valve delivers the highest quality and highest value available for your requirements. After a test of over 100,000 cycles at 720 psi (49.6 Bar), the seat remained in excellent condition, continuing to provide a bi-directional zero leakage seal. Even after more than 878,000 cycles at 2 psi (0.1 Bar), the McCannalok high performance valve still sealed zero leakage in both directions.