Val-Matic 14 and Larger Wafer and Lug Style Dual Disc Check Valve - Manual (Page 3)

INSTALLATION
The installation of the valve is important for its
proper operation. The flow arrow on the valve body
or nameplate must point in the direction of flow when
the system is in operation. The valve can be
installed in horizontal or vertical lines with the flow
up. Valves for air service (Series 8900) require
special springs to allow full valve opening.
The valve should be installed between standard
flanges per ANSI B16.1 or AWWA C207. The
gasket can be rubber or compressed fiber.
Three diameters of straight pipe upstream of the
valve are recommended to prevent turbulent flow
streams through the valve, which can cause
vibration and wear.
When mating the check valve with butterfly isolation
valves, the isolation valve must be installed at least
one diameter downstream of the check valve. The
check valve discs extend beyond the downstream
flange face and may interfere with the operation of
adjacent valves. A short run of pipe or spacer is
needed between the check valve and the isolation
valve.
2
LUG WAFER ENDS: Lug wafer valves should be
mated with flat-faced pipe flanges equipped with
resilient gaskets.
WAFER ENDS: Wafer valves should be mated with
flat-faced pipe flanges equipped with resilient ring
gaskets and full length studs.
INSTALLATION: Lower valve between mating
flange using slings or chains around the valve body.
The valves have a tapped hole for insertion of a
lifting eye if needed. Lubricate the flange bolts or
studs and insert them around the flange. Lightly turn
bolts or nuts until gaps are eliminated. The
tightening of the bolts should then be done in
graduated steps using the cross-over tightening
method. Recommended lubricated torques for use
with resilient gaskets (75 durometer) are given in
Table 1.
If leakage occurs, allow gaskets to absorb fluid and
check torque and leakage after 24 hours. Do not
exceed bolt rating or crush gasket more than 50 per
cent of its thickness.
125# FLANGE DATA 250# FLANGE DATA
Valve
Size
(in)
Bolt
Dia.
(in)
Bolt
Torque
(ft-lbs)
Valve
Size
(in)
Bolt
Dia.
(in)
Bolt
Torque
(ft-lbs)
14 1 80-250 14 1 1/8 140-450
16 1 90-300 16 1 1/4 180-600
18 1 1/8 100-350 18 1 1/4 190-600
20 1 1/8 120-450 20 1 1/4 220-600
24 1 1/4 150-500 24 1 1/2 350-900
30 1 1/4 180-600 30 1 3/4 500-1200
36 1 1/2 250-700 36 2 700-1500
42 1 1/2 300-800 42 2 800-1600
48 1 1/2 400-900 48 2 900-1800
54 1 3/4 500-1200
60 1 3/4 700-1500
TABLE 1. FLANGE BOLT TORQUES
CAUTION: The use of excessive bolt torque
may damage valve.