Val-Matic Wafer and Globe Style Silent Check Valve User Manual

Wafer and Globe Style

Silent Check Valve

Operation, Maintenance and

Installation Manual

Manual No.

SCV-OM1-2

INTRODUCTION.................................... 1

RECEIVING AND STORAGE................. 1

DESCRIPTION OF OPERATION...........1

INSTALLATION......................................2

DRAWING SS-974F...............................3

VALVE CONSTRUCTION...................... 4

MAINTENANCE ..................................... 4

TROUBLESHOOTING ........................... 5

DISASSEMBLY...................................... 5

REASSEMBLY....................................... 5

PARTS AND SERVICE.......................... 6

WARRANTY...........................................6

®

VAL-MATIC® VALVE AND MANUFACTURING CORP.

905 RIVERSIDE DR. ELMHURST, IL. 60126
TEL. 630 / 941-7600 FAX. 630 / 941-8042

WAFER AND GLOBE-STYLE SILENT CHECK VALVE

OPERATION, MAINTENANCE AND INSTALLATION

INTRODUCTION

This manual will provide you with the information to
properly install and maintain the valve to ensure a
long service life. The Silent Check Valve is ruggedly
constructed with bronze or stainless steel trim to
give years of trouble free operation. The valve
should be installed in horizontal or vertical pipes
carrying clean water. 14” and larger valves should
be equipped with special springs for operation in
vertical flow down applications.

The Silent Check Valve is designed to open fully to
provide flow in the forward direction and close
rapidly upon flow reversal. The valves are used to
prevent reverse flow through pumps or in piping
systems. The size, cold working pressure, and
model number are stamped on the nameplate for
reference.

This valve is not intended for fluids containing
suspended solids such as wastewater. For
wastewater and other high turbidity applications, use
Val-Matic Series 500 Swing-Flex

CAUTION: This valve is not intended for

fluids containing suspended
solids or hazardous fluids.

®

Check Valves.

RECEIVING AND STORAGE

Inspect valves upon receipt for damage in shipment.
Unload all valves carefully to the ground without
dropping. When lifting, the valve should be secured
by the body and never lifted by the bronze or
stainless steel trim.

The valves should remain crated, clean and dry until
installed to prevent weather related damage. For
long term storage greater than six months, the
rubber surfaces of the seat (when provided) should
be coated with a thin film of FDA approved grease
such as Lubriko #CW-606. Do not expose rubber
seat to sunlight or ozone for any extended period.

DESCRIPTION OF OPERATION

The silent check valve is designed to prevent
reverse flow automatically. On pump start-up, the
flow of water enters the valve from the seat end (left
side in Figure 1) and forces the disc open, allowing
the passage of fluid through the valve.

Wafer Style

Globe Style

IGURE 1. SILENT CHECK VALVES

F

n pump shut-down, the spring closes the disc

O

efore a flow reversal takes place. This type of

b

losure, which prevents flow reversal, is the factor

c

hich allows “silent” operation and prevents water

w

ammer associated with check valve slam.

h

he valve body is supplied with either compact

T

afer ends as shown in Figure 1 for installation

w

etween mating in a flanged

b flanges or

onfiguration, Figure

The only moving parts in the valve are

pring. The body bushing controls the movement of

s
the plug and assures that the plug contacts the seat
evenly. The valve may have an optional resilient
seal for drop tight service.

1

2. c
the plug and

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

stalled in horizontal oin
up or down. 14 inch and larger valves may require
extra heavy springs for flow down applications;
consult the factory.

Three diameters of straight pipe upstream of the

alve are recommended tv
treams through the valve, which can cause

s

ibration and wear.

v
When installed in ho

does not have a specific upward orientation. The
valve is usually installed so that the nameplate is
visible on the side of the valve for future reference.

MATING FLANGES: The valve should be installed
between standard flat-face flanges per ANSI B16.5
or AWWA C207. For globe style silent check valves,
the installation req

rawing SS-974F on page 3. The mating flange

D
inside diameter must overlap the valve seat to
provide proper seat retention. Flanges or pipes
having an expanded inside diameter (ductile iron or
mortar-lined pipe) ca

e valve. A ring flange having the maximum inside

th
diameter shown on the drawing must be inserted
between the valve and mortar-lined pipe. The
threaded seat wafer style silent check valves do not
require the mating flange to overlap the seat.

CAUTION: Mating flanges must be flat faced

WARNING: Flanges having an expanded

GASKETS AND BOLTING: The ring-type flange

asket can be rubber or compressed fiber but g
should
d o t

iameters sh wn in Drawing SS-974F. The gaske
must overlap eat to
provide a seal between the seat and the body.

langed valves with ring gaskets should use ASTM

F
A307 Grade B or SAE Grade 2 Carbon Steel bolts.
Higher strength bolts should only be used with full­face gaskets.

be a maximum of 1/16" thick with the

r vertical lines with the flow

o prevent turbulent flow

rizontal lines, the check valve

uirements are illustrated in

nnot be used on the inlet side of

or damage to the valve may
result.

inside diameter such as mortar­lined pipe cannot be used on the
inlet side of the valve or damage
may occur. Seat support rings
are needed.

the bronze or stainless steel s

A A valve

DJACENT V LVES: When mating the check
with butterfly isolation valves, the clearance between
the butterfly d e
stem must be s
also shown on .

isc and the fully open check valv

checked. The location of the stem i

the check valve submittal drawings
10 inch and smaller flanged end check valves have
sufficient clearance for most butterfly valves.
However, on 12 inch and larger valves, the plug
shaft extends beyond the flange face and may
interfere with the operation of adjacent valves. A
short run of pipe or spacer may be needed between
the check valve and the isolation valve.

INSTALLATION: Lower valve over mating flange
using slings or chains around the valve body.
Lubricate the flange bolts or studs and insert them
around the flange. Lightly turn bolts until gaps are
eliminated. The

tightening of the bolts should then
be done in graduated steps using the crossover
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) (in) (ft-lbs) (in)

2.5 5/8
3 5/8
4 5/8
5 3/4
6 3/4
8 3/4

10 7/8
12 7/8
14 1
16 1
18 1 1/8
20 1 1/8
24 1 1/4
30 1 1/4
36 1 1/2
42 1

Bolt
Dia.

1/2 42 2

Bolt

Torque

25-75
25-75
30-90
30-90

30-90
40-120
45-150
65-200
80-250
90-300

100-350
120-450
150-500
180-600
250-750
300-900

Valve

Size

Bolt
D

ia.

(in)

2.5 3/4
3 3/4
4 3/4
5 3/4
6 3/4
8 7/8

10 1
12 1 1/8
14 1 1/8
16 1 1/4
18 1 1/4
20 1 1/4
24 1 1/2
30 1 3/4
36 2

Bolt

Torque

(ft-lbs)

25-75

35-75
50-150
70-150
70-150
90-200

110-300
160-450
140-450
180-600
190-600
220-600
350-900

500-1500
700-2000
800-2500

TABLE 1. FLANGE BOLT TORQUES

C TIONAU : The u raise face es

se of d- flang or

xce olt que m

e ssive b tor ay

am e es.

d age valv flang

2