Instruction Manual
D500242X012
A31A Cryogenic-Rotary Valve
February 2019
2
Table 1. Specifications
Available Valve Configurations
J
Flangeless, wafer‐style or
J
single‐flange (lugged)
control valve with a one‐piece extension housing and
either NOVEX seal (standard), Kel‐F seal (optional) or
Kel‐F seal with Aluminum backup V‐ring (optional)
Valve Sizes
J
3,
J
4,
J
6,
J
8,
J
10,
J
12,
J
14,
J
16,
J
18,
J
20, or
J
24‐inch
End Connection Style
J
Flangeless, wafer‐style or
J
single flange valve
body designed to fit between raised‐face mating
flanges per ASME B16.5 Class 150 or 300
Maximum Inlet Pressure/Temperature
(1)
Consistent with ANSI Class
J
150 and
J
300
pressure/temperature ratings per ASME B16.34,
except that 38
_
C (100
_
F) rating is applicable to
‐254
_
C (‐425
_
F). NOVEX seal maximum
pressure/temperature rating is the same as the valve
body. See figure 2 for rating of Kel‐F seal.
Valve Classification
Face‐to‐face dimensions are in compliance with MSS
SP68 and API 609 standards; valve bodies are
designed for installation between ASME B16.5 Class
150 or 300 raised‐face flanges
Materials of Construction
See Bulletin 21.1:Cryogenic‐Rotary
Installed Valve Orientation
See figure 3 for orientation guidelines
Available Actuators
J
1035,
J
Bettis Pneumatic or
J
1051/1052
Disk Rotation
Clockwise to close
1. The pressure/temperature limits in this manual, and any applicable code or standard limitation, should not be exceeded.
Description
The A31A Cryogenic Series C (3‐ through 6‐inch Class 150 & 300 and 8‐inch Class 150) High Performance Butterfly
Valve features either a double D drive shaft to allow direct coupling to the 1035 actuator or keyed shaft (optional). The
A31A Cryogenic is a reliable, high‐performance butterfly valve for cryogenic applications.
The A31A Cryogenic is available in either a flangeless (wafer) or a single‐flange (lugged) valve body style and a variety
of seals.
The standard seal for the A31A Cryogenic valve is the NOVEX
t
metal seal which provides tight shutoff, low operating
torques and the ruggedness required for cryogenic service. Kel‐f and Kel‐f/aluminum seals are also available.
Installation
WARNING
Always wear protective gloves, clothing and eyewear when performing any installation operations to avoid injury.
To avoid personal injury or property damage resulting from the sudden release of pressure, do not install the valve
assembly where service conditions could exceed the limits given in this manual or on appropriate nameplates. Use
pressure‐relieving devices as required by government or accepted industry codes and good engineering practices.
Check with your process or safety engineer for any additional measures that must be taken to protect against process
media.
If installing into an existing application, also refer to the WARNING at the beginning of the Maintenance section in this
instruction manual.
