Rubber expansion joints have been specified and used for many years by donsulting engineers,
mechanical contractors, pressure vessel designers, plant engineers and turn-key construction firms.
They are installed to accommodate movement in piping runs, protect piping from expansion and
contraction and insure efficient and economical on-stream operations.
Rubber expansion joints provide time-tested ways to accommodate pressure loads, relieve movement stresses,
reduce noise, isolate vibration compensate for misalignment after plants go on stream the life of motive equipment.
Rubber expansion joints, designed by dngineers and fabricated by skilled craftsmen,
are used in all sytems conveying fluids under pressure and/or vacuum at various temperature:
1) Air Conditioning, heatiing and ventilating systems in commercial and institutional buildings, schools,
apartments, stores, hospitals, motels, hotels and aboard ships.
2) Central and ancillary power-generating stations in communities, factories, buildings and aboard ships.
3) Process piping in paper and pulp, chemical, primary metal and petroleum refining plants.
Types of mainly used Rubber Joints
1) Single Spool Arch Type
Single Spool Arch Type construction is of fabric and rubber, reinforced with metal riings or wire. The full face flanges are interal
with the body fo the joint and drilled to conform to the bolt pattern of the companion metal flanges of the pipeline.
This type of rubber face flange is of sufficient thickness to form a tightseal against the metal flanges
without the use of gaskets. The shortest face-to-face dimensions are available with this type of construction.
2) Multiple Spool Arch Type
Multiple Spool Arch Type joints with two or more arches may be manufactured to accommodate movements greater than those of
which a single arch spool type is capable. Multi spool arch joints of most manufactures are composites of standard-sized arches
and are capable of movemensts of a sing arch multiplied by the number of arches.
The minimum length of the joint is dependent upon the number of arches. In order to maintain lateral stability and prevent sagging
when the joint is installed in a horizontal position.
3) Filled-Arch Type
Arch-type expansion joints may be supplied with a bonded-in-place soft rubber filler to provide a smooth interior bore.
Filled arch joints also have a seamless tube so the arch filler cannot be dislodged duriing service. Filled arches, built as an
integral part pf the carcass, decrease the flexibility of the joint and should be used only when necessary. 0
Movements of expansion joints with filled arches are limited to 50% of the normal movements pf comparable size
expansion joints with unfilled(open) arches.
4) Belt “DOGBONE” Type
A molded construction of plies of wubber impregnated fabric, rubber covred and sliced endless, to a specified peripheral dimension.
Used as a flexible connention in central power stations on condensers. Designed for compression and lateral movements for full
vacuum service and a maximum pressure of 15 PSIG. Must be used with special clamping devices normally supplied by
the condenser equipment maunfacturers.