HURNER Hydr. 315 2.0 Manual De Instrucciones página 31

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Then push the carriage mover lever to its close-in position
while simultaneously turning the maximum pressure regula-
tor gradually clockwise. Watch the pressure gauge closely to
observe at which pressure level the carriage is "dragged" to
start moving. Take note of this value, preferably on paper,
as the drag pressure P
The exact drag pressure depends on various condi-
tions (pipe size and material, position of the ma-
chine, etc.) and has to be determined for every
Important
welding individually. The value P
pute the bead build-up, the heating, and the join-
ing pressures needed for jointing (stages t
t in the welding diagram, respectively).
5
4.3.3 Bead Build-up Stage
Use the welding value tables in the Appendix to look up the
joining pressure (i. e., the maximum pressure that will be
reached during the process, in the bead build-up stage and
at the end of the joining stage) appropriate for your situ-
ation. Then set the maximum pressure regulator to joining
pressure plus drag pressure (see Sect. 4.3.2) while observing
the actual pressure shown on the gauge, and move apart
the carriage of the machine. Using the welding value tables,
check that the heating element ("hot plate") has the correct
temperature and insert it between the pipe butts, move the
carriage in on it, and press the components to the heating
element at a pressure of P
tion given in the welding value tables in the Appendix (t
the diagram above).
4.3.4 Heating Stage
After the bead build-up stage (t
pleted, the pressure must be decreased to below or equal
to the level of P + P
2
applied for the entire duration of the heating stage (t
the diagram), in which the pipe butts continue to soak heat
from the plate. Use the welding value tables in the Appen-
dix to determine the heat-soaking time (t
(P2 + Pt) applicable to your welding situation. To reduce the
pressure applied to the pipe, use the pressure release valve
and observe the pressure level on the gauge.
Full contact has to be continuously established be-
tween the heating plate and the bead, even with
lower pressure. While heating, if contact between
Important
them is lost somewhere along the circumference,
welding has to be aborted and repeated.
Version October 2021
for this welding operation.
t
+ P for the bead build-up dura-
1 t
in the diagram) was com-
1
. The decreased pressure will then be
t
HÜRNER Manual Hydr. 315 2.0 User's Manual
is needed to com-
t
, t , and
1 2
in
1
in
2
) and pressure
2
15
EN