Cameron Demco - Operation; Manually Operated

9
TC-003001-01 / Rev 2
OPERATION
DEMCO Resilient Seated Butterfly Valves should never be operated without a handle or other means of controlling
the disc.
Caution: Failure to restrain the disc under flow conditions can result in the disc slamming closed and possible
damage or broken parts.
2" through 12" DEMCO Resilient Seated Butterfly Valves have flats on the upper stem. 14" and larger valves have a
single square key. Stem flats or the square key indicate valve position. When they are in line with the flow stream,
the valve is open. When perpendicular, the valve is closed.
MANUALLY OPERATED
DEMCO Resilient Seated Butterfly Valves operate from fully-open to fully-closed by a 90° turn of the handle. The
handle is marked with a flow arrow. When this arrow is in line with the pipe axis, the valve is open (Figure 11).
When perpendicular to the pipe, the valve is closed (Figure 12).
V alve
Size (in.)
Disc Swing
Size (in.)
Opens into:
Std Pipe
Sch 40
Sch 80
2"
1.467"
X
X
X
2 1/2"
2.144"
X
X
X
3"
2.743"
X
X
X
4"
3.601"
X
X
X
5"
4.582"
X
X
X
6"
5.624"
X
X
X
8"
7.428"
X
X
X
10"
9.382"
X
X
X
12"
11.35"
X
X
X
14"
12.86"
X
X
N/A
16"
14.72"
X
X
N/A
18"
16.61"
X
X
N/A
20"
18.53"
X
X
N/A
24"
22.57"
X
X
N/A
30"
28.67"
X
N/A
N/A
36"
34.70"
X
N/A
N/A
Table 5 - Disc Clearance
Figure 11 – Valve Shown Open
Figure 12 – Valve Shown Closed