July 28th-29th , 2020
DESCRIPTION.
As part of the training imparted by Kobus Inc Engineers, we met with Nicor Gas at their new site in Glenwood IL where we would be pulling old galvanized gas services and replacing with HDPE. The purpose of this visit is to ensure our customers are fully trained on our Technology and Pipe Puller, that the best practices on Health and Safety are met and finally give advice from our own experience gained after years of pulling in different countries, materials and soil conditions.
All pipes removed were 3/4″ galvanized steel and they were replaced with ½” HDPE. The typical lengths of the services were between 30 and 65 ft between the main and meter (by dwelling), soil and substrate was consistent with loose and moist soil at depths of 4 ft.
Two services were replaced during the training and only an excavation by the main was required as the pipe from the meter was on a soft bend downwards which allowed us to feed the cable with no further excavation or preparation. This saved considerable amount of time and only one pit was needed of 4ftx4ft by the main. This excavation, due to the presence of a large tree, took approximately two hours due to heavy rooting around service and main. The road remained open at all times.
Duration of actual pulls varied from 3 to 5 minutes (for day two pulling the 30ft service and for day one pulling the longer 65ft service). We utilized both the cables commercialized by Kobus Inc, the 14 mm (approx. 9/16″) and the 10 mm (approx. 3/8″) depending on lengths, service diameter and soil conditions to good effect. (14mm on the first day and longer service to evaluate soil conditions).
Whilst we tried to do the trial right after the show, due to C-19, we had to abandon and retake in September.
The trials would comprise two days replacing galvanized ¾” and some sort of ½” plastic in San Bernardino and Perris, CA. In both days we would be replacing with ½” HDPE and tracer cable from the main to the outside meter of the dwelling. The lengths of the galvanized were 40, 50 and 60ft and 50ft for the plastic ones.
The services were on the first day at a depth of 3-3.5ft in a medium hard compacted sandy soil and the second day about 5-6ft deep in extreme conditions of hard compacted and dry soil. It was actually so hard, that it had to be broken with the breaker.
As mentioned above, first day we replaced three services with minimal excavation at main (3x3ft) and meter. As there were other works required, the riser was excavated out, so we pulled all on straight line this time. There were no issues and all three pulls were perfect in times of 3 to 3.5 minutes each. Due to the 360° foot rotation of the KPP400, the road was kept open at all times and all health and safety measures where in place by SoCal, SouthWest Directional and of course Kobus Inc.
The second day saw us heading to a very arid area in Perris replacing ½” plastic which is now becoming brittle and needs replacing. Due to the terrain, pulling was pretty challenging and limited to 50ft sections.
On both pulls, the speed was reduced to slow, this to ensure the ground would have a degree of “giving” as the old service pulls out (likely to ball up). This is part of the technique which allows the ground to accept the slightly increased diameter of the balled up service.
On the first pull, the cable snaped after 40-45 ft of pulling. Upon inspection and spot digging the area, it was agreed that the roots of a large tree right on top had grown around the service making it impossible to be pulled. Nevertheless, the last 5ft were open trenched and the service connected. The old service as expected had balled up but it was progressing well until the root came to play. The new service towed in was checked for damage and it was flawless; no scoring and no gauges.
The second pull of also 50ft was successful and pulled well. SoCal insisted on an intermediate small pit to see the effects of the old service balling up. The result was good as its diameter was only slightly bigger than the expander already fitted to our Kobus Pulling cable.
Excavator used: John Deere 35G
OUTCOME.
Whilst training, attention is always on H&S and supervision of the crews, therefore high productivity is not pursued. This is something the crews will gain with time and continuous use of The Kobus Pipe Puller. The crew was outstanding, eager to learn and use our technology, grasped the simple concept of Pipe Pulling quickly.
Attention is also given to the actual Pipe Puller itself to ensure it is performing as intended, with no mechanical nor hydraulic issues. Kobus Inc Engineers also set up the excavator to best suit the requirements of the KPP400.
Over the training period, we experienced no set backs, cable failure nor Pipe Puller issues. No strikes with neighboring utilities were recorded either. Training was carried out by certified Kobus Inc Personnel with ample experience on the Pipe Puller and technique, ensuring safety standards were always in place.
Over the trial period, we experienced no set backs, one cable failure and no Pipe Puller issues. No strikes with neighboring utilities were recorded either. Trials were carried out by certified Kobus Inc Personnel with ample experience on the Pipe Puller and technique, ensuring safety standards were always in place .
FEEDBACK.
Nicor Gas was happy with the training imparted on their crews and hoping to be using the Pipe Puller on the extensive replacements programs. This is the second Pipe Puller for Nicor Gas; Des Plaines IL location acquired theirs last year.
Tom Atienza (Kobus Inc – VP Operations)
