Line Stopping Specialists

There are several methods of line stopping, each designed to suit different pipeline materials, sizes, and pressure conditions. Some common line stopping methods include:

Mechanical Line Stop: In this method, a mechanical stopper or plugging head is inserted through the hot tap and positioned inside the pipeline. The stopper is then expanded or pressed against the pipe wall to create a tight seal that blocks the flow of gas. Mechanical line stops are widely used due to their versatility and compatibility with various pipe materials and sizes.

Inflatable Line Stop ("bagging off"): This method uses an inflatable bladder or balloon that is inserted into the pipeline through the hot tap. Once in position, the bladder is inflated, sealing the pipe and stopping the flow of gas. Inflatable line stops are suitable for low-pressure pipelines and are often used in the water and wastewater industries.

Pivot Head Line Stop: Pivot head line stops utilise a hinged, articulating plugging head that is inserted into the pipeline through the hot tap. The head is then pivoted into place and locked in position, blocking the flow of gas. This method is especially useful in pipelines with bends or irregularities, where a straight mechanical stopper may not provide an adequate seal.

Foldable Line Stop: This method involves inserting a flexible, foldable plugging head into the pipeline through the hot tap. Once inside the pipe, the plugging head is unfolded and pressed against the pipe wall, creating a seal that stops the flow of gas. Foldable line stops are useful for large-diameter pipelines or pipelines with limited access points.

Each line stopping method has its advantages and limitations, and the appropriate method is chosen based on factors such as pipeline size, material, pressure, and specific project requirements.

Line stopping offers several benefits to the gas and pipeline industry, making it an essential technique for maintenance, repair, and modification work. Some of these benefits include:

Minimised downtime: Line stopping allows technicians to perform maintenance or repair work on pipelines without completely shutting down the flow of gas. This helps minimise downtime, ensuring continued service for customers and reducing the potential for lost revenue.

Enhanced safety: By temporarily stopping the flow of gas, line stopping creates a safer working environment for technicians. This reduces the risk of accidents and injuries that could occur if they were to work on a live pipeline.

Cost-effective: Line stopping eliminates the need for system-wide shutdowns, which can be costly and time-consuming. It enables targeted repairs or modifications without affecting the entire pipeline network, resulting in significant cost savings.

Reduced environmental impact: Line stopping prevents the need for venting or purging the gas to the atmosphere during maintenance or repair work. This reduces greenhouse gas emissions and minimises the environmental impact of pipeline operations.

Flexibility: Line stopping can be used on a wide range of pipeline materials, sizes, and pressure conditions, making it a versatile solution for various applications in the gas and pipeline industry.

Preventive maintenance: Line stopping can be used as a preventive maintenance measure, allowing technicians to isolate and address potential issues before they escalate into more significant problems that could compromise the entire pipeline system.

Line stopping and hot tapping are two distinct procedures that are often used together, but they serve different purposes.

Hot tapping is the process of creating a new connection or branch in an existing pipeline while it is still in operation. This is done by drilling a hole into the pipeline using a specialised cutting tool and then attaching a new pipe section or a valve to the hole, all without stopping the flow of gas or causing any leakage. Hot tapping allows for modifications or additions to be made to the pipeline system without interrupting service or causing downtime.

On the other hand, line stopping is the process of temporarily stopping the flow of gas in a pipeline, allowing for maintenance, repair, or modification work to be conducted safely. This is achieved by inserting a line stopper into the pipeline through a hot tap, which blocks the flow of gas, creating a safe working environment. Once the work is completed, the line stopper is removed, and the gas flow resumes. 

In summary, hot tapping is used to create new connections or branches in a live pipeline, while line stopping is used to temporarily stop the flow of gas in the pipeline for safe maintenance or repair work.