Robotics-as-a-Service & Technology Deployment

First Ever U.S. Deployment of CISBOT to Remediate Mechanical Joints

Over the past 10 years, internal robotic cast iron joint sealing has transformed the way that gas distribution networks manage critical gas infrastructure. CISBOT has historically been deployed to jute-lead joints in live mains, which make up a large percentage of the large diameter cast iron mains. However, this leaves another portion of the U.S. large diameter cast iron construction which is made up of mechanical gasket-sealed joints, a joint type that became popular around the 1950s.

cast iron gas mechanical joint leakage

Seeing an opportunity to expand CISBOT’s capabilities, National Grid collaborated with ULC Technologies’ engineering and operations teams to identify minor design modifications for CISBOT based on the specifications of mechanical joints. They also needed to modify the system to accommodate new joint sealing methodology and movement of more viscous sealant being used in the process. ULC then designed and built mechanical joint test rigs inhouse that allowed the team to perform rigorous R&D testing to confirm the effectiveness of the process in pressurized test pipe samples provided by our clients in a controlled environment, before taking the technology into the field.

Once successful testing had been completed, National Grid identified a gas main located under a busy commercial district on Rockaway Boulevard in Queens, NY which was ideal for a pilot project. Upon completion of the 10-day project, ULC was able to successfully seal 30 mechanical joints in a 24” bolted pipe using the modified CISBOT robot and new joint sealing methodology.

LOCATION:
Queens, NY

EXCAVATIONS:
1

JOINTS SEALED:
30

PIPE DIAMETER:
24″

JOINT TYPE:
Mechanical/Bolted

PRESSURE:
10psig / 689mBar

“ULC Technologies is one of the most innovative, reliable, and professional companies we engage with on a multitude of solutions to manage our underground assets. The ULC team did a phenomenal job in innovating the traditional jute-lead joint sealing to include mechanical joints, enabling the technology to increase the lifespan of our assets. The tool works on a live main and causes minimal disruption to our customers and communities we serve.”

– Pradheep Kileti, P.E. | Director, Future of Heat Engineering and R&D Program Management

gas main mechanical joint remediation

Background:

Large diameter cast iron gas distribution (12”+) mains were installed between the late 1800s and mid-1900s to deliver large volumes of natural gas to customers in urban areas and commercial districts. Over the years, the joints that connect the pipe segments have dried out and become prone to leakage.

Over the past 10 years, internal robotic cast iron joint sealing has transformed the way that gas distribution networks manage critical gas infrastructure. CISBOT has historically been deployed to jute-lead joints in live mains, which make up a large percentage of the large diameter cast iron mains. However, this leaves another portion of the U.S. large diameter cast iron construction which is made up of mechanical gasket-sealed joints.

Since National Grid has been utilizing CISBOT to address jute-lead joints for more than 10 years, they wanted ULC to adapt the successful technology to mechanical style joints to improve efficiency, reduce costs and minimize disruption to the public.

Solution & Benefits:

To seal mechanical joints, CISBOT requires minor design modifications including a shortened drill bit, new laser block and increased pump pressure capabilities to support a higher viscosity sealant than what is currently used for jute/lead joints. These modifications were made to accommodate the specifications and methodology associated with mechanical joints as compared to jute-lead bell joints.

In October 2021, ULC’s field team successfully sealed 30 mechanical joints using CISBOT in National Grid’s network in Queens. The U.S. pilot project enabled ULC’s teams to validate the modifications made to the robot as well as the mechanical joint sealing procedures.

Benefits of using CISBOT for mechanical joint sealing include:

  • Reduces the cost and time associated with having to excavate over every joint
  • The small site footprint allows for less disruption to the public, especially in populated urban areas
  • No disruption of gas service for customers
  • Mitigates the risk of gas leaks, therefore minimizing environmental impact

“Utilizing a new technique created in partnership with ULC and CISBOT, gas field operations were able to remediate approximately 522 feet of 24” cast iron main with mechanical joints which were installed in 1948. With just one excavation needed, this process will serve to extend the lifespan of the pipe, reduce impact on environment and avoid any disruption of service to our customers for many years to come. This had a real positive impact on some of National Grid’s key stakeholders, particularly customers and the local authorities.”

– Mattia Auriemma | Manager of Field Operations Downstate New York

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Interested in mechanical or lead yarn joint remediation? Our team is available to support.

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