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USER MANUAL
AcuDrill
DRILLING MACHINE
Edition: June 2016
Revision: No. 4
MODE OF USE
-
27
3.5
DRILLING UNDER PRESSURE OVER STEEL FITTINGS FOR GAS PIPELINES: 3-WAY TEES
AND THREADED O-RINGS OF 1½” - 2"
3.5.1
Initial operations:
Before performing the drilling operations, ensure that you have all the
necessary material and that it is in good condition.
C
Complete drilling machine.
C
Arbor hole saw (with pilot drill installed) matching the size of
the hole saw to be used.
C
Hole saw of the diameter to be used.
C
Drilling machine dome-sandwich valve adapter.
C
Sandwich valve with adapter to the fitting thread (1½” or 2").
C
Tool for internal plug installation.
C
Tools: 3mm & 5mm Allen keys, adapter spanner, 17mm open-
end spanner, ½” ratchet wrench (manual drilling) and
hydraulic or pneumatic swivel gear with chuckshaft adaptation
elements (if applicable), ratchet wrench 3/4".
3.5.2
Fitting installation:
Install the steel fitting (3-way tee or TOR-threaded O-ring) following
the procedure established by the Gas Company.
It is recommended to remove the exterior plug but keep
the internal plug (without o-ring) fitted in position during
the fitting preparation and welding. Once the welds cool,
remove the internal plug and install its O-ring.
3.5.3
Sandwich valve installation:
Figure 35
C
Remove the grease from the fitting internal thread.
WARNING !
Use Teflon® tape of equivalent to the sandwich valve adapter thread to
achieve tightness. Check good condition of the upper and lower sandwich
valve O-rings.
C
Install the 2½” sandwich valve with the adapter corresponding the fitting thread
size (1½” or 2"). See
Figure 35
. The sandwich valve gate shall be in OPEN
position.
3.5.4
Assembly of the drilling machine:
C
Set up the arbor hole saws with the pilot drill in the chuckshaft. Screw the hole
saw matching the threaded outlet of the branch connection into the arbor hole
saw. See
Figure 36
.