Solinas-TechnicalArticle-final

The Plastic Pipe Problem (and Opportunity)

When plastics emerged as a key material for construction and infrastructure projects in the aftermath of the Second World War, no one was quite ready for how quickly it would become a dominant material type for pipeline infrastructure. Two variants, PVC and HDPE, were particularly well suited for pipeline construction, and were first crafted into water and gas mains in the 1950s. Many thousands of miles of pipeline were installed in the growth years of 1950s and 1960s.  

However, only in the late 1960’s did utilities realize that they had a problem – they could no longer locate the metallic water or gas mains using magnetic locators. They were effectively blind to where they had installed these plastic pipeline assets, and in the late 1960s they started to lay tracer wire on top of the plastic pipe for locating purposes. While effective, early tracer wire had corrosion issues which weren’t addressed for almost a decade.

The net result is that today many utilities operate hundreds of miles of plastic gas and water mains that create locating challenges every time a utility locate is required. For gas operators, a faulty or mis-located utility could cause serious damage, bodily harm, and risk to their license to operate.

Legacy Approaches

Industry has been developing novel technologies to try and locate un-marked buried plastic pipeline for years, and some progress has been made. The most popular categories of solutions are as follows:

  • Ground Penetrating Radar: Typically mounted on a cart due to the size and weight of the technology, GPR is quite affective in the right conditions. Unfortunately, it has limitations in many soil types, potentially upwards of 70% of the common soils found in N.A. False positives can result from an incorrect measurement in poor soil conditions.
  • (Electronic) Witching Rods: The concepts of witching have long been in the back pocket of many a locator. Efforts to digitalize and make into a product have been received by a skeptical locating community.
  • Acoustic Devices: Come in a few shapes and sizes, from devices that impart a tapping force onto the pipeline directly, and listen along the pipe, to devices that generate a sound and receive a bounce-back signal all in the same enclosure, measuring location and depth. Another solution requires positioning a sensor directly into the gas stream and measuring the effect on gas molecules. The range of intrusiveness varies, and so does efficacy.

Time for a Novel Approach

FIG1. Equipment Required

By reframing and simplifying acoustic theories to plastic pipeline locating, we believe that a new way to locate is possible. Here’s how:

  • Charge up your field replaceable and fully rechargeable standard batteries for the SF1000 the night before you head out locating.

  • Once onsite, access the pipeline asset via an exposed point – typically the gas meter (if gas main) or a hydrant (if water main). A variety of access points exist depending on the utility, and the pipeline you are locating. Connect the receiver (the listening device) on the gas service.
  • FIG2. SonicFinder1000 display

    Once paired with the transmitter, you move toward the buried asset with the portable transmitter which creates an acoustic condition. Once the transmitter hovers over the service of interest, the device will indicate that you are in fact locating the pipe via the transfer of the noise generated back to the listening device.

  • Mark out the buried pipe asset in a series of passes, and de-mobilize to the next site.

[Schematic from the brochure, SF1000 with parts labelled]

Our Advantages

The SonicFinder1000 is a step change towards efficient, and consistent, location of plastic pipes. Some highlights include:

  • Works in a broad variety of soils, making it much more versatile than the ground penetrating radar carts
  • Proven to be reliably accurate
  • Acoustic technology allows for process signal filtering and frequency targeting
  • Advanced version of our technology will automatically create a virtual asset in a GIS platform (e.g. Esri)

Simply put, it works.