How it Works
The three sections of the sag remover are
assembled inside a manhole. Two air hoses are connected. One to
supply a pneumatic powered vibrator and one to power the lift
circuit.
After the machine is positioned in the sag,
static lift pressure is applied. This forces the center section,
which contains the vibrator, against the top of the pipe. The
sag is lifted when the vibrator is turned on.
Most of the lifting power comes from the
centrifugal force of the vibrator. The rubber isolator pads at
the ends of the machine prevents this vibration energy from
transferring downward.
Intense high frequency vibration allows the
surrounding granular bedding material to flow from above the
pipe to underneath, as the pipe is lifted.
Using the arching pad, sags of any length can be
removed by moving the machine in increments and lifting along
the length of the sag. Deeper sags will require multiple passes.
If
the bedding material contains fine particles that tend to pack
when the material is dry, it will likely be necessary for the
material to be wet to be able to flow underneath the pipe.
Coarser graded materials will typically flow ok either wet or
dry. |