Pneumatically driven earth-piercing tools make short work of installing 2- to 4-in. fiber-optic, water, and gas line services trenchlessly.
Available for decades from a variety of manufacturers, almost all available models on the market work well when they are new. But they’re not new for long. Designed to pound their way through soils job after job, their performance incrementally declines from the moment they are first turned on until eventually it’s unacceptable.
However, choosing serviceable tools and following the OEM guidance for their use, preventive maintenance routine and repair go a long way toward maintaining like-new tool performance and overall cost of ownership.
In-house vs. off-site maintenance
Some brands of earth-piercing tools must be sent out for servicing, requiring specialized equipment and OEM-certified service personnel. This requires scheduling and time and cost for shipping or transportation, not only adding to the owner’s workload but negatively affecting utilization rates. Being able to service the tools in-house eliminates the extra hassle, as well as shipping costs and higher maintenance fees.
One utilities company sought to lower cost and increase utilization rates of its 60 earth-piercing tools in-house. The tools are used on a daily basis. The company believed that giving immediate in-house attention to a tool’s servicing needs would maintain its peak performance better, extend its useful life and greatly improve utilization rates.
Yet the contractor encountered obstacles they had not counted on. Their current brand of tools not only required OEM-certified technicians but special equipment for disassembly and reassembly.
While the company’s technicians were receiving initial training from the dealer, they observed another dealer technician performing the same service on a different brand. The tech brought in the tool and without any special tooling completed the work in less than 20 minutes before setting the tool aside tagged for return to its owner.
Rather than invest in a specialized wrench for their in-house shop, the contractor arranged with the dealership to begin rotating out the earth-piercing tools it owned for the other brand. Today, the company owns only that brand of earth-piercing tool and performs all maintenance in-house. The tool can even be serviced in the field from the bed of a pickup truck.
Operate Tools per OEM Guidance
The contractor mentioned above worked with the dealership to receive OEM training. In a one-day workshop scheduled for the training, the manufacturer’s instructor taught the contractor’s personnel how to detect various types of damage and troubleshoot their cause, such as improper oiling and dirt contamination. He also educated the technicians on the relationship of volume to pressure.
For instance, most compressors used for this application are rated to run on less than 110 psi. This brand’s tools were designed to run at 110 psi, the highest in the industry. The pressure rating alone is insufficient for matching them to a compressor, however. Air volume is equally if not more important. The compressor must have the capability to maintain 110 psi pressure at sufficient volume throughout the run. The tool may even stop functioning midway through a run without the air volume and psi it needs.
On the other hand, excessive pressure can lead to more serious problems. The tool may be more productive running at pressures higher than the OEM specifications, but it will damage the tool. The clearest signs of excessive pressure are tools with broken or deformed bodies, flanges or tail pieces.
Running an earth-piercing tool above its rated pressure is also dangerous to personnel in the pit handling them. Protect personnel, tools and equipment from excessive pressures by adding a regulator to the compressor and running it at the OEM-specified psi.
The best advice is to use only OEM-authorized kits and parts and to follow the manufacturer’s guidance for tool care. The following are often overlooked steps that will help any earth-piercing tool owner get the most from their investment.
- Cleaning – With the piercing tool lying on the ground, turn the air on to allow the striker to hit in both direction for a few seconds to allow dirt and debris to exit the tool.
- Lubrication– During operation the tool should exhaust a light mist of oil that coats the whip hose. Properly adjusted and oiled, the whip hose is neither coated with oil (wasting oil) nor dry (out of oil).
- Storage – Before storing the tool, pour a few ounces of oil down the whip hose, tipping the tool side to side. This permits the striker to move the oil throughout the inside of the body. Place a gel cap over the end of the hose.
- Inspect all hoses – Ensure the rubber coating is not missing, exposing the metal bradding.
- Inspect head for wear – Visually inspect heads to determine if it’s time for replacement.
- Performance – When the piercing tool’s performance decreases, conduct inspection and maintenance. This is easily done, involving only a quick replacement of the wear rings on the striker and valve of models designed for ease-of-service.