Clamping The Components And Facing Their Butts - Hürner HWT 400-M Manuel Utilisateur

where the following applies for the coefficient:
α = 11.25 deg.
α = 15 deg.
α = 22.5 deg.
α = 45 deg.
Sample calculation:
Material PE 80, d. 90 mm, SDR 11, α = 45 deg. for a 90 deg.
joint, bead build-up
P
P =
=
α
coeff
α
Do not neglect that every welding operation performed for the pro-
duction of tees, crosspieces, and Y branch-offs (refer to Sect. 5.2) is an
angled joint that requires computing as above the pressure values from
the values in the tables in the appendix, depending on the angle.

4.4.1 Clamping the Components and Facing their Butts

Prior to starting the facing proper, install in the base of the facing
tool the spacer bolts for 0 mm, 5 mm, 10 mm or 15 mm distance
travelled during facing (refer to the figure to the right) that match
the facing distance you intend for the joint at hand.
Then perform the facing process as follows:
1. Move the carriage apart using the mover lever.
2. Tilt down the facing tool between the two carriages, but do
not use the locking bolt yet. The facing tool then will sit in its
Position 1.
3. Use the carriage mover lever to close in the carriage on the other
one, so both abut against the spacer bolts. In this position, the
component butts can be properly adjusted to the facing disk and
can be levelled in the clamping tools.
4. Clamp the components to be jointed into the clamping assemblies.
5. Move the carriage apart using the mover lever, tilt up the facing
tool from in-between the component butts, and close in the car-
riage again using the mover lever. Reduce the pressure slightly at
the pressure release valve and check for any vertical or horizontal
alignment offset. If the components misalign, adjust them, so
there is no unacceptable offset. If this requires repositioning
them along their longitudinal axis, repeat steps 3 and 4 before
you continue.
6. Move the carriage apart again and reinsert the facing tool be-
tween the components, but pull the locking bolt out this time,
so the facing tool slots down into its Position 2.
7. Turn the facing tool on at its On/Off switch and close the car-
riage in at a pressure of max. 10 - 15 bar, in order to press the
component butts against the facing blades. In the case of an
unsatisfactory facing outcome, you may still have to set the
pressure at 5 - 10 bar higher.
The farther the carriage mover lever is pushed to the left,
the faster the carriage closes in and the faster pressure in-
creases. The farther it is pushed to the right, the faster the
carriage of the machine moves apart, and the faster pressure
Info
decreases.
Facing should continue until shaving forms a continuous blade that
rolls twice or three times around the component ends, so the butts are
level. Use the manual pressure release regulator to lower the pressure
manually while the facing tool is trimming the components.
16
EN
— coeff = 0.981
α
— coeff = 0.966
α
— coeff = 0.924
α
— coeff = 0.707
α
5.0 bar
P = =
7.0 bar
45°
0.707
HÜRNER HWT 400–M User's Manual
H Ü R N E R S c h w e i s s t e c h n i k G m b H
Nieder-Ohmener Str. 26
35325 Mücke, Germany
Spacer bolts of the facing
tool: bolt for 5 mm of dis-
tance travelled during facing
in position, others "parked"
Facing tool position 1,
upper, for clamping the
components: carriages
touching the spacer bolts
Facing tool position 2, lower:
carriages slide over spacer
bolts at the end of facing, to
allow for moving closer in on
facing tool
Version January 2020