SEO Version
Installation Instructions for Convoluted Molded PTFE Bellows
ENGINEERING DESIGN NOTES:
1.
It is essential that piping system thrusts be calculated to ensure cor-
rect sizing of anchors and pipe supports, plus ensure that allowable thrust
forces on adjacent mechanical and rotating equipment are not exceeded.
Please use the following formulas:
T
p
= P • T
f
T
p
is the pressure thrust (lb
f
),
P
is the system operating pressure (Psig)
and
T
1
is the thrust factor (or bellows effective area [in
2
]). The pressure
thrust,
T
p
, will act in the axial direction and must be added to the axial
spring force
(Fx•
∆
x)
to give the total axial reaction force,
Rx
.
Rx = T
p
+ (Fx •
∆
x)
Rx
is the pipe support reaction force (lb
f
),
T
p
is the pressure thrust (lb
f
),
Fx
is the axial spring force of the unit and
∆
x
is the expected or designed
axial movement of the unit (See Tables 1-9).
2.
It should be noted that axial spring rate values found in Tables 1
through 9 are based on an ambient temperature (70
°
F) and will decrease
as the system temperature rises. In addition, spring rates decrease over
time due to thermoplastic creep if units are operated under pressure.
1. Service Conditions:
Make sure the expansion joint ratings for tempera-
ture, vacuum, spring rates and movements match the system requirements.
Contact PROCO if the system requirements exceed those of the expansion
joint selected.
2. Alignment:
Expansion joints are not designed to make up for piping
misalignment error. Pipe misalignment should be no more than 1/8" in any
direction. Misalignment of an expansion joint will reduce the rated move-
ments and can cause stress of material properties, thus causing reduced
service life.
3. Limit Rod Bolting:
Limit bolts are factory set at the maximum allowable
travel position to prevent over extension. Do not remove or alter nuts at
any time. Damage or personal injury can result due to changes in limit rod
nut settings.
4. Anchoring:
Solid anchoring is required whenever the pipeline changes
direction. Expansion joints should be located as close as possible to these
anchor points. If an anchoring system is not used, any associated pressure
thrust can cause excessive movement, ultimately damaging the expansion
joint.
(It should be noted that the attached limit rods are designed to
limit movement and are not designed to handle pressure thrust.)
5. Pipe Support:
Piping must be supported by hangers or anchors so
expansion joints do not carry any pipe weight.
6. Personnel Protection:
It is strongly recommended that safety shields
be used for all hazardous service to protect against serious personal in-
jury in the event of expansion joint failure. (See Back Cover.)
7. Installation:
a.
Store expansion joints with plastic covers in-place to protect PTFE flange
surfaces from damage until ready to install.
Pump
Foundation
Anchor
Expansion
Joints
Guide
Expansion
Joint
TYPICAL PUMP AND PIPING LAYOUT USING
EXPANSION JOINTS WHEN EQUIPMENT AND
PIPING ARE PROPERLY ANCHORED.
b.
Check to make sure PTFE surfaces are clean and free of foreign sedi-
ment. Remove nicks, burrs and deep scratches with a fine emery cloth. If
surface irregularities cannot be completely removed, install a PTFE enve-
lope-type gasket to obtain an adequate seal.
c.
Install expansion joints to the prescribed neutral lengths. If expan-
sion joints are used in high temperature processes, it is recommended
that units be installed at near extended values. For cold process instal-
lations, expansion joints should be installed in a nearly compressed
length. These settings will enable the expansion joint to realize full
travel capabilities.
d.
Thread installation bolts from mating flange side to prevent possible
damage to PTFE elements. Extend bolts beyond the expansion joint flange
by no more than 1-2 threads. Nuts are not necessary due to threaded
flange holes.
e.
Tighten flange bolts with a torque wrench. Tighten in an alternate
crossing pattern in 20% increments until 80% of final bolt torques have
been achieved. Tighten to final torque values (listed in torque table list-
ing) in a clockwise fashion around the flange to ensure bolts carry equal
stress burdens.
f.
Re-tighten bolts after first cycle of operation. Re-tighten as necessary
after every planned maintenance shutdown. All bolts should be re-torqued
to the above listed values.
8. Operations:
After expansion joints are installed, it may be necessary to
air blast the exterior to remove foreign debris, such as metal chips, from
between the convolutions. The expansion joint should then be covered
with a shield to protect from damage and foreign debris during operation.
(Note: Do not weld in immediate vicinity of expansion joint unless it is
properly protected.)
SIZE
I.D. (IN)
SIZE
I.D. (IN)
SIZE
I.D. (IN)
SIZE
I.D. (IN)
TORQUE
(FT/LBS)
TORQUE
(FT/LBS)
TORQUE
(FT/LBS)
TORQUE
(FT/LBS)
TORQUE TABLE LISTING
1
15
3
30
10
55
20
85
1.25
15
4
35
12
60
22
90
1.5
15
5
40
14
70
24
90
2
20
6
44
16
75
— —
2.5
25
8
50
18
80
— —
PRESSURE RATING (psig)
Deg F
EXTRA
HEAVY DUTY
OPTIONAL PRESSURE RATINGS
70
°
145
290
250
°
62
107
100
°
120
217
300
°
48
85
150
°
72
175
350
°
44
70
200
°
62
125
400
°
38
65
LIGHT
DUTY
PRESSURE RATING (psig)
Deg F
EXTRA
HEAVY DUTY
LIGHT
DUTY
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