Top 10 Keyhole Uses For Smart Construction

February 2014, Vol. 69 No. 2

2. Cathodic protection
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Extending the life of buried metal pipes by connecting them to sacrificial anodes is an easy keyhole application, and one every gas or water utility should adopt. Using keyhole coring and vacuum excavation equipment to access pipes buried under pavement and long handled tools to clean the pipe and weld on the connection is simple, safe and reliable. The process is fast and efficient and the comparative pavement restoration costs are a fraction of conventional methods and can save more than $1,000 per hole.

3. Cast-iron joint leak repair
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Some cast iron gas pipes have been in the ground for 100-years or more and are prone to leaks between the bell and spigot. These leaky joints can be repaired by encapsulating the joint with a boot or sealing it with an anaerobic sealant using long handled tools through a cored keyhole. The process has been used for more that 15 years and the reinstatement of the core can save entire streets from being ripped up and repaved.

4. Subsurface Utility Engineering (SUE)
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Visually identifying and measuring the exact location of buried infrastructure is an essential element of the mapping of buried infrastructure before final engineering drawings are completed. SUE can save more that $4 for every $1 invested. But opening a hole in the pavement using conventional excavation methods that require extensive and costly pavement repairs afterwards can wipe out these savings very quickly. Using keyhole coring and reinstatement allows SUE companies to get in and out without damaging the roadway, while still obtaining the exact utility depth and location measurements required for “A” level SUE work. Keyhole coring and reinstatement makes the SUE process faster and even more cost-effective.

5. Service cut-offs
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Cutting off a service from the main, or sectionalizing the pipe for safety reasons after a main has been abandoned, is a perfect application of the keyhole process as many gas utilities look to reduce the punitive costs of pavement rehabilitation and large cut-backs imposed by municipalities for these small openings. Tooling for these applications is readily available, and processes have been well developed over the years to cover a multitude of different types of service cut-offs using the keyhole process.