Additional Bending Information - Southwire PVCHB-13 Instructions De Fonctionnement Et D'entretien

TECHNICAL DATA
FORMING
Heat the PVC conduit with the PVC Heating Blanket until softened,
making sure the entire length to be bent is evenly heated. When
forming bends on pipe sizes ½" through 1-1/2" diameter, it is
not necessary to use bending plugs. Once the conduit is ready
to be formed, it can be installed in place and can quickly be set
by cooling with a rag or sponge and cold water. Should several
identical bends be required, or if a specific degree of bend or
radius is necessary, a simple wood jig can be fashioned for fast,
identical bends. We recommend that any form be made from
non-heat conducting material.
NOTE: It is difficult to achieve bends tighter than four (4) times
the diameter of the pipe equaling the inside radius of the bend
(4 X Dia= Inside Radius) without controlled manufacturing
conditions.
PREVENTING DEFORMATION
Conduit and ducts 2" diameter and larger may crimp, flatten,
or deform during the bending process. Bending plugs help to
eliminate this problem. Bending plugs are inserted into the ends of
the conduit before heating. Our adaptors slip over the plugs and
are used for half size conduit and for belled-end pipe. During the
heating cycle, the bending plugs cause the trapped, heated air,
inside the conduit to expand, creating enough pressure inside the
pipe to keep the walls of the conduit supported during the bending
process. This slight amount of pressure is critical in keeping the
walls of the pipe from collapsing or when making a bend. If a plug
pops-out during the bending process, it may be necessary to
reinsert the plug and reheat the pipe to complete a smooth, kink
free bend.

ADDITIONAL BENDING INFORMATION

Very tight radius bends are difficult to achieve with any size
PVC pipe, conduit or duct without the use of special production
techniques. These techniques can include air pressurization of
the piece, insertion of special internal supports, or some other
technique. The following table can be used as a guide that is
applicable to many types of rigid PVC conduit and duct:
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