СʪÃÃÊÓƵ

A comprehensive guide to equipment, regulations and best practices for hot tapping hazardous liquids, natural gas and hydrogen pipelines

In the face of growing energy demand, the need for efficient and reliable pipelines has never been greater. And with much of the world’s energy infrastructure constructed 50, 60 or even 70 years ago, pipeline integrity activities are surging, too. 

Much of this work relies on hot tapping as a proven preparatory step. The hot tapping procedure, which involves cutting or drilling a hole into the operational pipe, enables the deployment of isolation equipment to create a safe work zone prior to repairs, maintenance or modification. 

Though some pipeline operators choose to evacuate and shut down their systems prior to isolation, hot tapping is faster, more efficient, better for the planet and the company’s budget. There’s no large-scale product venting, reduced fugitive emissions associated with purging procedures when stopping and restarting the system, and no lost production.

Tapping Machines shown in use in the field.

Hot tapping:

• Reduces downtime.
• Minimizes operational disruption.
• Ensures continuous service to customers.

• Limits environmental impact. 

• Mitigates safety risks. 

Tapping Machines: The Heart of the Hot Tap

The hot tap machine is the heart of the hot tap procedure. It would be impossible to safely and efficiently perform a hot tap without it. 

These specialized machines are engineered for a wide variety of applications, environments and pipeline materials and sizes. They’re also designed to handle specific pressure ranges and pipeline materials.

The hot tap machine is connected to a valve which is attached to the hot tap fitting, this allows access to the pressurized pipeline. Hot tap fittings are typically made of high-strength materials to withstand the pressures and stresses involved in the process. A wide range of specialized fittings makes hot tapping possible in more demanding applications, such as pipelines with thicker walls or unusual geometries.

The hot tap fitting is welded onto the in-service pipeline following approved weld procedures, becoming a permanent part of the pipeline. In-service welding is complex and challenging — and even more so in the confined spaces often encountered while working in the ditch. Fortunately, service providers can take several steps to mitigate risk, beginning with a thorough assessment beforehand and the development of stringent safety protocols, and equipping well-trained, highly qualified personnel with the right equipment.

Typical tapping setup

Hot Tapping Systems: Versatile Solutions for Any Pipeline Size and Material

offers over a dozen hot tapping configurations that cover any and all types of pipelines, from steel to polyethylene (PE), and sizes ranging from half-inch taps to 108-inch taps. Each tapping machine is engineered to exceed industry standards and is backed by decades of technical expertise and first-hand field experience. Among the offerings, the 1200 Series provides a versatile, high-performance solution for operators. For more specialized needs, the 2460 XXL system incorporates remote-controlled operation and real-time data monitoring, enhancing both safety and efficiency. Together, these are just a small sample size of the machines that utilizes to ensure that pipeline operators have the right tools for any job, enabling safe, reliable, and efficient hot tapping operations in even the most challenging environments.

Examples of various sizes of tapping machines.  

Close Cuts

The primary component of the hot tapping machine is a rotating cutter. 

These workhorses are made of high-strength, wear-resistant materials that can withstand the high pressures and abrasive conditions encountered during the hot tapping process. Tapping Machines can by powered by electrical or pneumatic motors but are most commonly powered by hydraulics. Theses systems use pressurized fluid to generate the operating force and are often preferred for larger hot tap machines or more strenuous applications. The alternative would be a pneumatic system, which uses compressed air instead. Hot tap machines equipped with hybrid power sources can be powered by a combination of hydraulic and pneumatic systems. This means they can adapt to different pipeline conditions and requirements and potentially be used in a wider range of applications.

Once the hot tap machine has been secured to the valve and a leak test has been performed to ensure the integrity of the gaskets, technicians use its cutting tool cut and capture the coupon, once fully retracted, the valve is closed and the tapping machine is removed. A competent technician is trained to monitor the variations in pressure supplied to the tapping machine which allows for continuous monitoring of the tapping process.

After the hot tap is complete, the tapping machine is removed, and the isolation and pipeline repair, maintenance or other work can proceed.

Criteria for Success

To ensure the success of the , the hot tap machine must be:

• In prime operating condition, following a robust maintenance schedule.
• Able to maintain pressure within the pipeline.
• Operated by a competent technician.
• Configurable.
• Manufactured from quality materials.
• Designed to meet high safety standards.

Hot tap machine manufacturers are constantly upgrading technology to improve safety, efficiency and versatility. 

For example, today’s hot tap machines often feature remote-controlled operation, allowing operators to perform the procedure from a safe distance, which reduces the risk of incidents. Other advanced safety features include automatic shut-off valves, pressure-relief devices and leak-detection systems, all intended to protect personnel and minimize environmental hazards. Some hot tap machines are equipped with data-logging capabilities for real-time monitoring of critical parameters — pressure, temperature, cutting tool performance, isolation valve position and overall equipment status — during the hot tapping process and can be integrated with pipeline management systems for seamless data sharing. 

Unique Each Time

Though hot tapping is common, there’s nothing routine about it. Each hot tap is unique and requires careful planning to ensure safety and success. Together, the operator and service provider must consider a wide range of factors and variables, including:

• Pipeline conditions, material properties, wall thickness and pressure rating. 
• Environmental conditions — temperature, humidity, site conditions, simultaneous operations, excavation quality, and potential hazards. Extreme weather conditions or the presence of flammable materials can affect hot tap safety. 
• The suitability of the equipment for the specific pipeline and product. 
• Safety protocols and emergency procedures.

The properties of the product flowing through the pipeline is also a key consideration. While service providers are familiar with hot tapping pipelines carrying gas or hazardous liquids, the shift toward more sustainable energy sources, such as , will likely have significant implications for hot tapping procedures. There are several reasons for this. First, hydrogen has a lower ignition point and has a larger flammability rate than traditional pipeline products. Second, hydrogen can cause metal embrittlement, which makes pipelines more susceptible to cracking or failure and increases the risk of leaks over time. Finally, welding hydrogen pipelines requires specialized procedures and equipment to prevent hydrogen-induced cracking and related failures. 

Safer Than Ever

While the core principles of hot tapping remain the same, advances in technology and an increased focus on safety have led to new and best practices. 

Stricter safety criteria include requirements for qualified personnel, equipment inspections and formal emergency response plans. are becoming more stringent, with an increased focus on potential leak containment and cleanup.

The (API) has published several widely recognized standards for hot tapping:

• API 1104 covers the design and fabrication of hot tapping equipment — including isolation pressure relief and control valves, hot tap fittings and saddles, which are devices used to support the hot tap machine — as well as testing to verify the equipment’s quality and integrity.
• API 6D outlines design criteria and material specifications for valves, considering factors such as pressure, temperature, fluid properties and operating conditions. It also specifies testing procedures to confirm valve quality and performance.
• API RP 1106 provides guidance on the safe execution of hot tapping operations, including risk assessment, emergency procedures and post-tap inspection.

In addition, the Pipeline Hazardous Materials Safety Administration (PHMSA) has addressed hot tapping procedures and best practices in regulations and guidance documents. For example, 49 CFR Part 192 includes provisions related to the design, construction, operation and maintenance of natural gas pipelines, including hot tapping operations, while 49 CFR Part 195 covers the same topics but for hazardous liquids pipelines. 

Conclusion

Hot tapping, while not without risk, is the most effective way to access in-service piping systems while simultaneously minimizing environmental impact. Drilling into a pressurized pipeline is not something any service provider takes lightly.

But with careful planning, proper equipment and skilled crews, hot tapping can be completed without incident, allowing pipelines to keep flowing, powering our communities and supporting our everyday activities. That’s a testament to the advancements in technology and the expertise of the professionals involved. It's reassuring to know that this essential technique is a reliable and effective way to maintain and improve the performance of the world’s energy infrastructure.