Basically, a time relay is used to adjust the duration of wye connection
that effects current and torque impulse which are reduced as the motor gets closer to synchronous speed.
For instance, a 6'' manufactured wye connection
with a 4" lateral pipe will result in a large void space and thus more residual grout.
With an easy to use hand drill and drill guide, a watertight wye connection
can be achieved in just a few minutes saving the contractor time and money.
Articulated--With the ever increasing need to tie-in marginal fields to one main trunkline, wye connections
are becoming common.
Roots are killed on contact inside and outside pipe walls, and the foam penetrates through wye connections
to kill roots in lateral lines.
After installation, the crew uses TV inspection equipment to examine the repaired pipe and deploy a remote-controlled pneumatic cutter to open up the wye connections
to the active house laterals.