Innovation From Concept to Commercialization
Field Deployment of Advanced Technology

CISBOT Robotic Remediation of Large Diameter Cast Iron Gas Mains

Live internal joint sealing allows gas utilities to avoid the tremendous cost of cast iron pipe replacement or other forms of pipeline rehabilitation. ULC’s Robotic Joint Sealing service with CISBOT rehabilitates leaking joints, prevents joints from leaking and extends the life of your cast iron natural gas mains with minimal excavation and continuous service to utility customers. ULC Pipeline Robotics has sealed more than 30 miles of large diameter cast iron mains for gas companies in the United States and Europe in major cities such as Boston, New York, London and Edinburgh. Save money, time and improve customer satisfaction by greatly reducing permit, engineering and restoration costs, and eliminating the disruption caused by direct burial construction.

Gas Main Rehabilitation

CISBOT: Key Benefits

01. Global Operations

Ongoing joint sealing operations with CISBOT are performed in New York, London, Boston and Edinburgh to extend the life of large diameter cast iron gas mains.

02. Cost Effective

CISBOT is more productive and cost effective than other internal and external joint sealing methods – which can cost up to 50% more. Our tools require only one excavation and thus lower permit, engineering and pavement restoration costs.

03. Precise, Computer Controlled Operation

CISBOT precisely drills into each joint and injects sealant using a computer-controlled system. The drill pressure and flow rate are continuously monitored to ensure a full joint seal every time.

04. Reduce Repetitive Maintenance

By sealing all joints in the main, utilities eliminate the need to return to the same locations year after year to carry out maintenance and leak monitoring.

05. Proven 50-Year Performance

We internally drill and inject every joint with a well-proven anaerobic sealant that has a 50-year effective life as tested and verified by Cornell University.

06. Performed in Live Mains

The entire joint sealing process from the time we launch the tool head into the main through the internal drilling and injecting process and the robot retrieval procedure can be performed without shutting down service to customers.

07. Small Site Footprint

With just a small excavation and our CISBOT box truck, local residents and businesses can go about their daily routines with less public disruption and road closures than other replacement or repair methods.

08. Comprehensive Reporting

Our utility customers receive in-pipe video and daily work reports that detail the work that was completed, how much anaerobic sealant was injected for each joint, as well as an accurate site map outlining joint locations and other pertinent information.

Gas networks use our robotic inspection and joint renewal services to avoid the tremendous cost and disruption associated with direct burial replacement of large diameter cast iron gas mains.

  • CISBOT No-Blow Launch Tube
  • CISBOT Project in Edinburgh, Scotland
  • CISBOT Tool Head
  • CISBOT Robotic Joint Sealing
  • CISBOT Cast Iron Joint Sealing

How it Works: The Science of Sealing Joints

Repeatable Methodology Ensures Positive Results: CISBOT first drills a small hole through the spigot to allow direct access to the jute packing material. The robot then positions a specialized nozzle over the newly drilled hole and injects an industry-proven anaerobic sealant directly into the hub. Circumferential rotation within the main allows CISBOT to drill and inject from any clock position to ensure the anaerobic sealant has completely filled the voids.

Monitoring the Process: Robot operators can monitor the joint sealing process using the six onboard cameras to look for wicking of the sealant and verification that the sealant is remaining in the joint.

Computer Feedback: A closed loop sensor feedback system informs the robot operator how well the joint is taking the sealant and how much was injected. This data is delivered to the client as part of the reporting data.

CISBOT Reporting and Data

Bar Hole Readings CISBOT

Detailed Joint Sealing Data: We treat every joint like its own construction project, providing highly detailed information about the makeup of the renewed joint.

Visual Data: Pre-inspection visual data reveals critical information about joint integrity and previously unknown features in the gas main.

Sub-Centimeter Location Data: Using our locating technology, our crew can also obtain pinpoint accurate location data for joints, tees, services and other features in the main to update utility mapping.

CISBOT Media Coverage

It’s important for us, our stakeholders and customers to make sure that we embrace innovation, chose the correct method of repairs, and  future-proof our networks to make sure they are done right the first time.

Watch Now: Cadent Media

R. Sansom, Cadent Gas


CISBOT delivered 850m of Gas mains remediation to this highly sensitive location in 9 weeks compared to 9 months via traditional methods, The impact on traffic was considerably reduced and at no time did customers have their gas supplies interrupted.”

Watch Now: London Live

J. Harrison, Cadent Gas


The main benefit for us is CISBOT enables us to keep the roads open, have the gas on at all times, and it massively reduces the duration of the work.”

J. Rowing, Westminster Council UK

Hiring ULC Robotics for the work with CISBOT on West End Avenue cost $400,000. To do the job the way such work used to be done would have cost $1.5 million to $1.8 million.”

Watch Now: ABC 7

J. Ciallella, Con Edison

May 2016

The Boston Globe

To fix buried gas mains, a robot dives in 


January 2018

The New York Times

New York Times Calls ULC’S CISBOT “21st-Centruy Repairman” 


January 2018


Unique robot repairing New York City gas lines with minimal interruption


October 2019

Evening Standard

New robot fixes street gas pipes 10 times faster than human counterparts


March 2019

NBC 5 On Your Side

What would usually take months can now be completed in just a few weeks


May 2019

Utility Week

Cadent Ramps Up Use of Robots for London Gas Network


Don't Miss Out on Our Technology and Innovation Updates:

Sign Up for Our Email Newsletter