CVHH-SVX001G-EN
35
Screw-Tightening Sequence for
Water Piping Connections
This section describes a screw-tightening sequence for
flanges with flat gaskets or O-rings. Remember that
improperly tightened flanges may leak.
N
No
otte
e:: Before tightening any of the screws, align the
flanges.
Flanges with 8 or 12 Screws
Tighten all screws to a snug tightness, following the
numerical sequence for the appropriate pattern as
shown in the following figure. Repeat this sequence to
apply the final torque to each screw.
Figure 22.
Flange screw tightening sequence (8 or 12
screws)
1
3
4
5
7
8
2
6
8 screws
1
3
4
10
11
9
5
7
8
12
2
6
12 screws
Flanges with 16 or 20 Screws
Tighten only the first half of the total number of screws
to a snug tightness, following the numerical sequence
for the appropriate pattern as shown in the following
figure. Next, sequentially tighten the remaining half of
the screws in numerical order.
Figure 23. Flange screw tightening sequence (16 or
20 screws)
16 screws
20 screws
1
5
9
20
2
3
4
6
7
8
10
19
18
17
16
15
14
13
12
11
1
5
9
2
3
4
6
7
8
10
16
15
14
13
12
11
Pressure Testing Waterside
Piping
N
NO
OT
TIIC
CE
E
E
Eq
qu
uiip
pm
me
en
ntt D
Da
am
ma
ag
ge
e!!
F
Fa
aiillu
urre
e tto
o ffo
ollllo
ow
w tth
he
esse
e iin
nssttrru
uccttiio
on
nss cco
ou
ulld
d rre
essu
ulltt iin
n
e
eq
qu
uiip
pm
me
en
ntt d
da
am
ma
ag
ge
e..
D
Do
o n
no
ott o
ov
ve
err p
prre
essssu
urriizze
e tth
he
e ssy
ysstte
em
m o
orr e
ex
xcce
ee
ed
d
d
de
essiig
gn
n p
prre
essssu
urre
e.. A
Allw
wa
ay
yss p
pe
errffo
orrm
m a
a h
hy
yd
drro
o p
prre
essssu
urre
e
tte
esstt w
wiitth
h w
wa
atte
err p
prre
esse
en
ntt iin
n p
piip
piin
ng
g a
an
nd
d w
wa
atte
errb
bo
ox
xe
ess..
Waterside design pressure is either 150 psig
(1034.2 kPaG) or 300 psig (2068.4 kPaG); refer to unit
nameplate or to submittal documentation.
Summary of Contents for CVHH CenTraVac
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