Fisher® POSI-SEAL A31D Double-Flange High-Performance Butterfly Valve0 pages

Product Bulletin

A31D Valve

21.1:A31D
April 2013

D500213X012

Fisherr POSI-SEALt A31D Double-Flange
High-Performance Butterfly Valve
The Fisher A31D double-flange high-performance
butterfly valve provides outstanding performance
under extreme pressure and temperature conditions.
The A31D valve is available with face-to-face
dimensions conforming to ISO 5752 Butterfly Valve
Short (CL150) or Long (CL300) Series (for other
face-to-face dimension requirements, consult your
Emerson Process Management sales office). A splined
shaft combines with a variety of Fisher
spring-and-diaphragm or pneumatic piston actuators.
A keyed drive shaft combines with a variety of
handlevers, handwheels, or pneumatic double-acting
or spring-return piston actuators. These combinations
make the A31D valve a reliable, high-performance
butterfly valve for both throttling and on-off
applications in the process industries.
The A31D valve can be supplied with one of several
dynamic seals (figure 1) that can be used in a variety of
demanding applications. With the appropriate seal
selection and materials of construction, the
pressure-assisted seal provides excellent shutoff
against the full ASME class pressure range.

Features

Excellent Shutoff Integrity-- The pressure-assisted
seal design provides tight shutoff and permits the
use of smaller actuators in applications requiring full
ASME B16.34 shutoff capabilities.

True Bi-directional Shutoff Performance-- A31D
valve design helps to ensure that the torque
necessary to open and close the valve is the same
regardless of the direction in which the differential
pressure is applied.

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X0704

Fisher A31D Valve with 2052 Actuator

Safety-- Shaft-blowout protection is designed into
the A31D valve (figure 2). For NPS 3 through 12
valves, the packing follower and an anti-blowout
follower hold an anti-blowout gland securely around
the valve shaft. Under the anti-blowout gland, a
formed wire ring around the shaft completes the
protection design. For NPS 14 through 24 valves,
the anti-blowout gland fits securely over the valve
shaft which has been turned down to form a
circumferential shoulder that contacts the
anti-blowout gland.