Data Sheet
A31A Valve
D500191X012
Product Bulletin
21.1:A31A
October 2013
3
Features
Economical Tight Shutoff–The pressure-assisted
seal design provides tight shutoff and permits the
use of smaller, less expensive actuators in
applications requiring full ASME B16.34 shutoff
capabilities.
Excellent Shutoff Integrity–Concentric rotation
helps to ensure that t he valve disc remains in the
closed position in spite of line pressure surges or
actuator failure.
True Bi-directional Shutoff Performance– Valve
design helps t o ensure that the torque necessary to
openandclosethevalveisthesameregardlessof
the direction in which the differential pressure is
applied.
Safety–Shaft blowout protection is designed into
theA31Avalve(figure3).Theanti-blowout gland
fits securely over the valve shaft which has been
turned down to form a circumferential shoulder
that contacts the anti-blowout gland.
Ease of Maintenance–Interchangeability of all parts
including shafts and discs simplifies service and
reduces maintenance costs.
Improved Environmental 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.
Reliable Flange Gasketing Surface–Seal retainer
screws are located so there is no interference with
the sealing function of either flat sheet or spiral
wound line flange gaskets.
Easy Installation–The valve body self-centers on the
line flange bolts as a fast, accurate means of
centering the valve in the pipeline.
Figure 1. Available Seal Configurations
B2334-1
VALVE DISC
VALVE DISC
VALVE DISC
BODY
BODY
BODY
BACKUP
RING
BACKUP
RING
SEAL RING
RETAINING
RING
RETAINING
RING
RETAINING
RING
GRAPHITE
GASKET
GRAPHITE
GASKET
NOVEX
SEAL RING
METAL
SEAL RING
RESILIENT
INSERT
HIGH PRESSURE
AT SHUTOFF
HIGH PRESSURE
AT SHUTOFF
HIGH PRESSURE
AT SHUTOFF
1
1
1
SOFT SEAL WITH
BACKUP O-RING
NOVEX SEAL
PHOENIX III SEAL
Note:
For optimum sealperformance, thepreferredvalveorientation
at shutoff is withthe retaining ring downstream from the high pressure
side of the valve.
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