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What is Keyhole Technology?


Keyhole technology methods can cut excavation and repair costs in half because they allow for a less intrusive method. Just like keyhole surgery in which surgeons create smaller incisions in order for scarring to be minimal and recovery to be quicker. Using keyhole techniques allows maintenance activities to be conducted through minimal openings in the pavement which results in noticeable cost savings, reduced inconvenience, and a quicker repair time frame. Keyhole technology provides a valuable alternative to regular excavation techniques and repair methods, which often require much larger holes, increased removal of unwanted pavements, etc, driving costs up. Just the equipment required to perform these traditional methods drive the costs way up compare to keyhole technology. Remember - when it comes to making holes, smaller is better!

Tellus Approach to Tooling Design

Tooling Designs Driven by Process Requirements

Tellus Underground Technology has more than 25 years of experience in the design of tooling and processes for the gas distribution utility industry. Our professional staff has developed “no-blow” and “keyhole” processes and equipment for scores of LDC’s and utility contractors in the U.S., Canada and Europe for the maintenance and integrity management of their gas distribution systems. Our experience and relationships have led us to the development of a unique and thoughtful method for the task tooling design. Our approach consists of a three step process beginning with (1) determination of a process that best suits the task to be performed, then (2) development of a safe, secure and cost-effective procedure to complete the process that has been selected and (3) design the tooling necessary to safely and efficiently complete the procedure that has been designed.

keyhole technology at work


gas utility inspection keyhole technology

(in “Keyhole” & “No-Blow” methods)

  • Leak location & repair

  • Service retirement (cut-offs)

  • Corrosion control

  • Service renewal

  • Anode installation

  • Service installation

  • Camera launching & inspections

  • Underground plant location

  • Meter replacement & relocation

  • Tracer wire repair

  • Test station installation

  • Gas evacuation emergency leaks

  • Tie-overs on main replacement



Selection and/or development of an operating process that best suits the operation or task to be performed

​Our use of the words process and procedure can sometimes be confusing. The word process can be thought of as “what” task is to be performed and the word procedure is used to describe the “how” or the steps utilized in the completion of a task or process. Our selection of a process that best suits the operation or task to be performed will vary based upon parameters such as the size of the main, material of the main/service, system pressure and hardware attached to the main.

An Operating Procedure - Selection or Development


Tellus Underground procedure mapping
keyhole technology camera

Flow Charts

​An operating procedure must be selected or designed before tooling can be specified or developed. When a tooling supplier short-cuts this important task he risks missing crucial steps in the procedure. These missed steps will often lead to unforeseen difficulties in completing the procedure and in some cases the complete failure of the process. When steps are missed the operator’s safety and effectiveness are compromised and when the process fails, operating personnel must resort to traditional methods that include blowing gas and increased risk factors.


Selection of the procedure that will be employed to address a customer’s particular need begins with a communication between the customer and a Tellus staff member to determine the gas operating system parameters and hardware configuration that will be designated for the operating process. If a matching procedure already exists, the customer receives a flow chart, a detailed set of operating instructions and tooling list so that the operating procedure can be adopted into his organization. In the event that no matching procedure exists, Tellus will develop a new flow chart and detailed set of instructions that meets all of the customers specific requirements followed by the design of tooling to meet all of the requirements to support this new procedure.

​Underground Technology you will find that it is important to link an operating flow chart to the step by step performance of your procedure. We have found it is extremely important that every gas mechanic follow the same sequence of well-designed steps, with properly designed tools, each time they perform the procedure. In the case of a thoughtfully designed “keyhole” procedure it demands that every detail of the process be addressed with functional tooling. If any step of the procedure is overlooked, or not adequately tooled, the process falls apart. The gas mechanic has no reasonable ability to safely reach into a 3 to 4 foot deep excavation to correct a tooling deficiency. When a step in the procedure is not properly addressed with adequate tooling the gas mechanic must resort to conventional methods by excavating a hole large enough to permit access to the underground infrastructure to complete the procedure. If the gas mechanic is performing a “no-blow” procedure and finds that one particular device or tool is not available he must abandon the “no-blow” procedure and resort to traditional methods. This situation always results in compromising the safety of the operator and a return to methods that the gas distribution industry would like to see replaced.

When you work with Tellus

Above is an example of a basic flow chart. We use this simple operating procedure to demonstrate the attention to detail that exists in every Tellus operating procedure.

Tools Specifically Designed for the Gas Distribution Industry

Tellus tools are unique and thoughtfully designed devices that meet the specialized needs of the professional gas mechanic who is performing “no-blow” and “keyhole procedures.

These are not merely tools on a stick but sophisticated pressure chambers, gas cameras, flow controls, metal machining devices, pneumatically driven power tools and specialized hand tools. Tellus tools are professional quality tools designed for use by utility professionals.

tools for gas distribution industry
reliable keyhole technology process

Design for Reliability

​Design for Reliability refers to the process of designing reliability into our procedures as well as our tooling, to insure that the gas distribution utility’s expectations are fully met. Reliability must be designed into each tool and procedure using the best engineering practices coupled with extensive experience in all possible failure mechanisms that exist. Our design process begins with an in depth study of each individual task necessary to perform every step in the procedure followed by a review of all of the mechanisms that may result in a breakdown of that procedure. Upon completion of this review we proceed with the design of each tool and component necessary to complete the procedure. In those cases where the utility’s process includes the use of hardware or components supplied by another manufacturer a Tellus staff member consults with that supplier so that we will understand their recommendations for installation of their product and to be advised of any restrictions they may have for its use. Only after all of this work is completed can we begin to test and map our operating procedure. Our new procedures are mapped using flow charts to summarize the procedure followed by an extensive testing program to insure that every failure mechanism has been fully addressed and optimum integrity and reliability have been built into every new procedure.


Reliability must begin early in the design process and must be well integrated into every tool and operating event of our procedures. Only then can we be confidant that gas utility professionals will realize the process reliablity they must expect.

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