Installation - Val-Matic Dual Disc Check Valve Operation, Maintenance And Installation Manual

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.
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.
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.
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.
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.
The valve can be
The
The
2
Table 1. Flange Bolt Torques
125# Flange Data
Valve Bolt Bolt
Size Dia. Torque
(in) (in) (ft-lbs)
14 1 80-250
16 1 90-300
18 1 1/8 100-350
20 1 1/8 120-450
24 1 1/4 150-500
30 1 1/4 180-600
36 1 1/2 250-700
42 1 1/2 300-800
48 1 1/2 400-900
54 1 3/4 500-1200
60 1 3/4 700-1500
CAUTION
The use of excessive bolt torque may damage
valve.
250# Flange Data
Valve Bolt Bolt
Size Dia. Torque
(in) (in) (ft-lbs)
14 1 1/8 140-450
16 1 1/4 180-600
18 1 1/4 190-600
20 1 1/4 220-600
24 1 1/2 350-900
30 1 3/4 500-1200
36 2 700-1500
42 2 800-1600
48 2 900-1800