Emerson Fisher POSI-SEAL A31D Data Sheet

Product Bulletin

A31D Valve

D500213X012

September 2014

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.

TheA31Dvalvecanbesuppliedwithoneofseveral
dynamic seals (figure 1) that can be used in a variety of
demanding applications. With the appropriate seal
selection and materials of c onstruction, the
pressure-assisted seal provides excellent shutoff
against the full ASME class pressure range.

X0704

Fisher A31D Valve with 2052 Actuator

21.1:A31D

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.

 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.

www.Fisher.com

Product Bulletin

21.1:A31D
September 2014

A31D Valve

D500213X012

 Excellent Emissions Capabilities-- The optional

ENVIRO-SEAL™ packing system is designed with
improved sealing, guiding, and loading force
transmission. The ENVIRO-SEAL packing system can
control emissions to below the EPA (Environmental
Protection Agency) limit of 100 ppm (parts per
million) for valves.

 Shaft Versatility-- This valve will meet your actuator

needs with a choice of splined or keyed shaft
connections.

Table of Contents

Features 1.....................................

Specifications 3................................

Installation 4..................................

Standard Seal Configurations 4...................

 Sour Service Capability-- Trim and bolting materials

are available for applications involving sour liquids
and gases. These constructions comply with NACE
MR0175-2002, MR0103, and MR0175/ISO 15156.

 Reliable Flange Gasketing Surface-- Seal retainer

screws are located so there is no interference with
the sealing function of either flat sheet or spiral
woundlineflangegaskets.

 Easy Installation-- The valve body self-centers on the

line flange bolts as a fast, accurate means of
centering the valve in the pipeline.

Tables
Materials of Construction and Temperature Ranges 6
Valve Body Material Pressure/Temperature

Ratings 8...................................

Dimensions and Weights 10......................

2

Product Bulletin

A31D Valve

D500213X012

21.1:A31D

September 2014

A31D Valve Specifications and Materials of Construction

Table 1. Fisher A31D Valve Specifications

SPECIFICATION

Valve Body Size NPS 3, 4, 6, 8, 10, 12, 14, 16, 18, 20, and 24

Pressure Rating Consistent with CL150 and 300 perASME B16.34

Valve Body Materials

Disk Materials CF8M Stainless Steel

End Connections Mates with RF flangesper ASMEB16.5

Valve Body Style Double Flange

Shaft Connection

Face-to-Face Dimensions

Shutoff

Flow Direction Reverse (flow direction is into the shaft side of the disk)

Flow Characteristic Approximately Linear

Disk Rotation Clockwise (CW) to close

1, See table 4 and figure 4 for additional information. The pressure/temperature limits in this bulletin and any applicable codes or standard limitation should not be exceeded.

2. 0.1 scfhper unit of NPS at 80 psi.

CL150: ISO5752 ButterflyValve ShortSeries

CL300: ISO5752 ButterflyValve LongSeries

Soft Seal: Bidirectional ANSI/FCI 70-2 Class VI

NOVEX Seal: Unidirectional MSS SP-61

Phoenix III Seal: ANSI/FCI 70-2 Class VI

WCC Steel

CF8M Stainless Steel

Spline (standard)

Keyed (optional)

(1)

(2)

3

Product Bulletin

21.1:A31D
September 2014

A31D Valve

D500213X012

Figure 1. Available Seal Configurations

BACK-UP
RING

SEAL RING

RETAINING
RING

E0578

Notes:

This unidirectional seal must be installed so that the retaining ring is downstream from the high pressure side of the valve at shutoff, as shown.

1

For this bidirectional seal, The “preferred” valve orientation places the retaining ring downstream from the high pressure side of the valve at shutoff.

2

BODY

VALVE DISC

SOFT SEAL WITH
BACK-UP O-RING

RETAINING
RING

LARGEST
OUTSIDE
DIAMETER

HIGH PRESSURE
AT SHUTOFF

NOVEX SEAL

GRAPHITE
GASKET

2

BODY

VALVE DISC

BACK-UP
RING

BODY

VALVE DISC

PHOENIX III

FIRE-TESTED SEAL

LARGEST
OUTSIDE
DIAMETER

SEAL RING

HIGH PRESSURE
AT SHUTOFF

1

LARGEST
OUTSIDE
DIAMETER

SEAL
RING

RESILIENT INSERT
HIGH PRESSURE
AT SHUTOFF

1

Installation

Recommended or “preferred” installation for the A31D
valve is with the flow into the shaft side of the disk
(retaining ring downstream from the high pressure
side of the valve).

The standard soft seal offers ANSI/FCI 70-2 Class VI,
bidirectional shutoff. The Phoenix III seal should be
installed in the preferred direction to obtain optimal
shutoff performance, and it must be installed in the
preferred direction for fire-tested applications. The
NOVEX seal is uni-directional and should be installed in
the preferred direction.

For assistance in selecting the appropriate
combination of actuator action and open valve
position, contact your Emerson Process Management
sales office.

Standard Seal
Configurations

 Standard Soft Seal (PTFE)-- A resilient dynamic seal

with an elastomeric back-up ring for low to
moderate temperature applications.

 NOVEX Seal-- The NOVEX stainless steel seal is

available for severe service, Cryogenic, and
high-temperature applications.

 Phoenix III Seal-- This three-component,

metal-and-polymeric seal is available for severe
service with low to moderate temperature
applications.

4