NIBCO Flanged End Outside Screw and Yoke Cast and Ductile Iron Globe and Angle Valves - Manual (Page 4)

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1.3 DETAILED DESCRIPTION
The globe and angle valves listed above and covered in these guidelines are iron valves
made of ASTM A-126; Grade B material for Class 125 and 250 cast iron valves and from
ASTM A-395 ductile iron material for Class 150 valves.
These valves are operated with the handwheel and are used to start, stop or throttle the
flow of fluids in piping systems. Globe and angle valves are rising-stem type only. When
the stem rises, (about 25 % of nominal size), it also turns. Non-rising stem globe valves
are not available. The disc is closed through a clockwise turning direction of the hand
wheel.
The bolted-bonnet type body and bonnet connection are held together by bolts and nuts.
There is a non-asbestos gasket between the body and bonnet to affect a seal. The Class
125 cast iron valves have a flat-faced flange. The Class 250 cast iron and the Class 150
ductile iron valves have raised-face flanges.
Flow-through globe or angle valves are stopped by forcing the disc down onto the valve
body seat. Throttling is accomplished by carefully turning the handwheel to some
position between fully opened and fully closed. The disc is either of solid bronze
construction or a bronze seat ring threaded onto an iron disc. In some cases where a
soft seat is desired, the disc is made out of PTFE (may not be currently available).
In the special non-return models (NR), the disc is so arranged that it travels up and down
within the valve body through the use of guides on the disc itself and it is not attached to
the stem.
This valve is a directional valve operated by gravity to prevent backflow. The non-return
feature will only operate in the direction of the flow arrow on the side of the valve. It may
also be used as a shut-off valve. This valve is not recommended for steam service.
2.0 INSTALLATION
2.1
PRELIMINARY INFORMATION
The globe valve should preferably be installed with the stem pointed vertically upward.
However, it is normally acceptable to have the valve stem in a horizontal position either
in vertical or horizontal piping. Although a globe valve will function satisfactorily in an
inverted position, it is not generally recommended because it allows fluids to become
trapped in the bonnet cavity resulting in contamination and inability to fully drain the
system.
N .R. modified globe valves or F-869-B, automatic steam stop check valves, operate by
gravity, therefore they must be installed with the stems in the vertical position. Any
deviation from vertical can cause excessive wear and/or valve malfunction.
Valves are shipped in the closed position to prevent damage to the seating surfaces.
There is no internal blocking used for shipment.