2 - 1
Theory of Heat Fusion
The principle of heat fusion is to heat two surfaces to a designated
temperature, and then fuse them together by application of force.
This pressure causes flow of the melted materials, which causes
mixing and thus fusion. When the thermoplastic material is heated,
the molecular structure is transformed from a crystalline state into
an amorphous condition. When fusion pressure is applied, the
molecules from each thermoplastic part mix. As the joint cools, the
molecules return to their crystalline form, the original interfaces are
gone, and the fitting and pipe have become one homogeneous
unit. A strong, fully leak tight connection is the result.
The principle operations include:
Clamping The pipe and fitting must be held firmly to allow all
subsequent operations to take place.
Cleaning The area of pipe that the fitting will come in contact
with must be cleaned and roughed up, as well as the
base of the fitting.
Aligning The fitting must be properly seated on the pipe and
then clamped in the machine for proper alignment.
Heating A melt pattern must be formed that penetrates into the
pipe and into the fitting.
Joining The melt patterns must be joined with a specified
force. The force must be constant around the interface
area.
Holding The molten joint must be held immobile with a
specified force until adequately cooled.
Inspecting Visually examine the entire circumference of the joint
for compliance with standards established by your
company, customer, industry, federal, state, or local
regulations.
Overview
PH00784-4-1-96
TX02497-06-17-14
To Next Page
Loading...