
Page 1 of 2 AUGUST 2012 G988
Grinnell Mechanical Products
Model CB800
Circuit Balancing Valve
Worldwide
Contacts
www.grinnell.com
Installation
Instructions
GRINNELL CB800 Circuit Balancing
Valves are designed for installation in
hot water heating and chilled water
air conditioning systems and serve to
achieve a hydronic balance between
the various circuits of the system.
These installation instructions are
designed for the Grooved, Flanged,
Threaded, and Soldered type Circuit
Balancing Valves.
General Instructions
Always read and understand the in-
structions. Never remove any piping
component without verifying that the
system is depressurized and drained.
It is the designer’s responsibility to se-
lect products suitable for the intend-
ed service and to ensure that pressure
ratings and performance data are not
exceeded.
It is recommended that the valve be
installed in the return line.
Install the valve with the flow in the
same direction as the arrow cast in
the body.
Valve must be installed with a mini-
mum of 3D (3 x nominal pipe diam-
eter) of straight pipe in the upstream
side.
Valve may be installed in the vertical
or horizontal position, with the hand-
wheel up, down or on the side.
Presetting:
The required preset value can be ob-
tained by referencing the flow chart
for the appropriate size of valve. (See
reference documents on www.grin-
nell.com) Following the steps below,
adjust the basic and fine adjustment
scale on the handwheel to match the
selected presetting.
Step 1. The preset value of the valve
is adjusted with the handwheel (See
Figure 1 or 2).
Step 2. Turn the handwheel so that
the arrow on the sliding indicator
matches the basic adjustment value.
One complete turn of the handwheel
adjusts the indicator one full position.
The fine setting is displayed in the
scale under the handwheel and in-
dicates 1/10th of a turn of the
handwheel.
Step 3. With the valve open to the
preset value, use a small screwdriver
and gently pry the cover plug out of
the hand-wheel. Using a 3 mm Allen
key for the 1/2 to 2 inch, 4 mm Allen
key for the 2-1/2 to 6 inch, or a 10 mm
screwdriver for the 8 to 12 inch, insert
the tool into the screw (see Figure 1 or
2) and turn clockwise until tight. This
will lock the hand-wheel so that the
valve can not be opened beyond the
preset value. The hand-wheel may still
be turned to the closed position. Re-
place the cover plug.
Repositioning the
Handwheel
Depending on the position of the valve
in the system, it may be desirable to
move the 1/2 inch to 6 inch handwheel
and adjustment scales to make it eas-
ier to read.
Step 1. Ensure the valve is closed
and the adjustment scale is set at 0.
Step 2. Use a small screwdriver and
gently pry the cover plug out of the
hand-wheel.
Step 3. Use a 12 mm socket for the
1/2 inch to 2 inch handwheel and
6 mm Allen key for the 2-1/2 inch to 6
inch handwheel to remove the Allen
screw (See Figure 1).
Allen Wrench
Handwheel
Figure 1
1/2 inch to 6 inch
handwheel Presetting and rePositioning
Indicator
Sliding
Marking Fine Setting Scale
(Peripheral Scale)
Handwheel
Cover Plug
Screw
Sealing Wire
Hole For
Sealing Wire
Hole For
(Longitudinal Scale)
Basic Setting Scale
1/10th of a turn
complete turns
Lead
seal
Cover
plug
Handwheel
Figure 2
8 inch to 12 inch
handwheel Presetting
and rePositioning