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Professional design flange type rubber bellows expansion joint
Metallic Pipe Expansion Joints
Product description
Metal pipe expansion joints can withstand the design temperatures,
pressures, as well as, provide the capacity necessary to absorb
thermal growth of the piping system.
The thermal movement required can be axial, lateral or angular. In
some cases, the pressure thrust of a pipe expansion joint must be
restrained by the use of tie rods, hinges or gimbal while allowing
the bellows to move through its design deflections.
Expansion joints with stainless steel bellows
Sunny Steel offers a wide range of expansion joints, suitable for
numerous specific applications.
The Sunny Steel expansion joints portfolio basically consists of
three main series:
The heart of all expansion joints is the metal bellows. Thanks to
modern design and manufacturing facilities, all BOA expansion
joints offer the following advantages:
Metallic Expansion Joints Installation Guide
Storage:
Handling:
Do not lift with ropes or bars through the bolt holes. If lifting
through the bore, use padding or a saddle to distribute the weight.
Do not let expansion joints sit vertically on the edges of the
flanges for any period of time. Do not lift on the shipping
restraints.
Service Conditions:
Make sure the expansion joint rating for temperature, pressure,
movements, and selection of materials match the system
requirements. Contact the manufacturer if the system requirements
exceed those of the expansion joint selected.
Alignment:
Expansion joints are not designed to make up for piping
misalignment errors. Check with the manufacturer if piping
misalignment is present.
Anchoring:
The main function of expansion joints is to compensate for axial
pipe thermal expansion. Metal expansion joints must have the
protection of adequate anchoring against the internal and thrust
pressures of the media to prevent damage. Anchoring must be
installed as close to the down stream end of the expansion joint as
possible, with the originating equipment serving as the opposite
anchor. Anchors must prevent pipe movement in any direction.
Hangers or pipe pedestals cannot be considered to be anchors as
they offer no restriction against side or end motion.
When designing an anchor for a metal expansion joint, consult the
internal thrust force table from the appropriate expansion joint
catalogue. The weight of piping, valves, and media, as well as the
resistance of the piping to deflection, must be included as part of
the design weight and strength of an anchor.
Anchors are required whenever a piping system changes direction.
Expansion joints should be located as close as possible to anchor
points. For additional expansion joint protection, it is
recommended that control rods be installed on the expansion joint
to prevent excessive movements from occurring due to pressure
thrust of the line.
Guides:
Expansion joints must be properly guided and anchored in accordance
with EJMA standards.
Pipe Support:
Piping must be supported so expansion joints do not carry any pipe
weight.
Mating Flanges:
Install the expansion joint flange against the mating pipe flanges
and install bolts so that the bolt head is against the expansion
joint flange. Bolts should be installed from the bellows side (so
that the bolt heads are adjacent to the bellows) to insure that the
bolts do not interfere with the bellows during periods of
compression. Flange-to-flange dimensions of the expansion joint
must match the required opening.
Make sure mating flanges are clean and are matched to the type
supplied with the expansion joint. Gaskets of appropriate material,
size and temperature ratings must be used in all flange-to-flange
type installations.
Bolt Torque:
Tighten bolts in stages by alternating around the flange. Never
tighten an expansion joint to the point that there is
metal-to-metal contact between the expansion joint flange and the
mating flange.
Shipping Restraints:
The expansion and compression movements are preset at the factory.
The shipping restraints protect the expansion joint in its neutral
position prior to installation. Remove the shipping restraints
after installation and before hydro-testing the system.
Additional Tips:
1. Insulation or thermal blankets over a metal expansion joint
should be supplied by the expansion joint manufacturer to preclude
the use of corrosive chloride bearing insulation materials.
Insulation should be installed to permit easy access to the flange
area, to check bolting.
2. Do not weld in the near vicinity of a non-shrouded expansion
joint without protecting the expansion joint from damaging weld
splatter.
3. If an expansion joint is to be installed underground, or will be
submerged in water, contact the manufacturer for specific
guidelines.
4. Consider ordering a spare expansion joint. The cost of downtime
of a critical expansion joint far exceeds the cost of a spare unit
placed and protected in reserve on-site.
5. Whenever possible, install the expansion joint next to an anchor
as indicated below not exceeding maximum distance to the 1st guide
with at least two concentric pipe guides on the opposite side of
the joint. Added guides are required to prevent bowing or bending
of the pipe.
6. When an expansion joint is placed elsewhere in the line, at
least two concentric guides must be used on each side of the joint
with added joints installed as recommended in pipe guide spacing
diagram.
7. The inside of all piping must be clean before installing and
testing the expansion joints. Expansion joints should not be
subjected to hydrostatic pressure tests beyond their rated working
pressure.
8. Secure all anchors and guides before testing. Remove shipping
bars prior to testing.
9. Expansion joints must be removed from the lines while the system
is being tested hydrostatically at pressure exceeding allowable
working pressure.
10. Expansion Joints fabricated with flow liners must be installed
with the flow arrow pointing in the same direction of the media
flow.
11. Single externally pressurized expansion joints must be
installed with the moving end adjacent to the moving end of the
pipe responding to the thermal expansion induced during system
heat-up.
12. Failure to install according to instructions will void
warranty.