Hot Tapping: Our Process And Useful Applications

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Hot tapping is a useful technique in a variety of industries and situations, particularly those where shutting down operations to perform pipeline modifications or interventions are impractical, costly, or could potentially lead to hazardous conditions.

Our engineers frequently carry out hot tapping procedures on any of the following systems:

Common applications

Natural Gas Pipelines

Hot tapping is commonly used with natural gas pipework to allow for the installation of new branches on existing pipelines. This allows the existing gas installation to be expanded or modified without the need to interrupt gas supply.

Food and Beverage Manufacturing Plants

In these plants, shutting down a pipeline for maintenance or modification can result in significant product loss and potential contamination risks. Hot tapping can be used to install new equipment or make necessary repairs while keeping the product flow uninterrupted.

Paper Manufacturing

Paper mills have extensive networks of pipes carrying steam, water, and various chemicals. Hot tapping allows for the installation of new sensors, valves, or connections without the need for a shutdown.

Steel Manufacturing

In steel plants, hot tapping can be used to add additional pipelines or modify existing ones in the gas supply network, without interrupting the gas flow. This is especially useful in plants where gases like oxygen, nitrogen or natural gas are used in large quantities.

Water Supply Networks

Shutting down a part of the water supply network for maintenance or modification can cause significant disruption to residents. Hot tapping can be used to carry out the necessary work without the need to shut down the supply.

Power Plants

In power plants, especially those operating with high-pressure steam, hot tapping allows for maintenance or modification work to be done without having to shut down the plant, thereby ensuring a continuous supply of power.

Heat Exchangers

In facilities with heat exchangers, hot tapping can be used to install nozzles or other components without having to drain the system, saving time and maintaining operational efficiency.

The key advantage of hot tapping is that it allows for modifications or repairs to be made to pipelines or vessels without interrupting the flow of the material within. This can result in significant cost savings, minimise downtime, and maintain the safety of the operation. However, it is a complex procedure that requires experienced professionals to carry out the work safely.

Hot Tapping materials

Hot tapping can be performed on a variety of materials, although the specific method and equipment used will depend on the type of material, its thickness, and the pressure and temperature of the system.

Some common materials that our engineers frequently work with include:

Mild Steel: This is one of the most commonly hot-tapped materials due to its wide usage in pipeline construction

Stainless Steel: Like carbon steel, stainless steel is widely used and can also be hot tapped. Different grades of stainless steel may require different hot tapping procedures.Mechanical fittings are normally used on mild steel

Ductile & Cast Iron: Commonly used in water and sewage pipelines, ductile iron can also be hot tapped, with mechanical fittings no welding required

PVC , UPVC, ABS Plastic pipe is another material that can be hot tapped, commonly used in water supply and sewage lines.

MDPE & HDPE: Frequently used in gas and water pipelines and can be hot tapped, but it typically requires specialised equipment and procedures.

Aluminium: In some cases, aluminium pipelines can be hot tapped, although this is less common.

Copper: Used often in smaller piping systems, like those found in HVAC systems, copper can also be hot tapped.

Hot Tapping limitations and alternatives

While hot tapping is a very useful method in many situations, there are some circumstances where it may not be the most appropriate choice. These include:

Extreme Temperatures and Pressures: Hot tapping is generally not recommended for pipelines or vessels operating at extremely high or low temperatures or pressures. The process could lead to material failure or other dangerous conditions.

Corrosive Materials: If the pipeline is carrying corrosive or erosive materials, hot tapping might not be suitable. The material could potentially damage the hot tapping equipment or pose a risk during the hot tap process.

Brittle Materials: Certain materials, such as some types of cast iron and hardened steels, can be too brittle for hot tapping. The process could lead to the formation of cracks or other forms of material failure.

Unpredictable Flow Conditions: If the flow conditions inside the pipeline are unpredictable or highly variable, hot tapping may not be suitable. This could make it difficult to control the hot tap process and increase the risk of an incident.

Lack of Structural Integrity: If the section of the pipeline where the hot tap is to be performed lacks sufficient structural integrity, then hot tapping should not be performed. This could be due to factors like corrosion, mechanical damage, or improper installation.

In situations where hot tapping is not suitable, some possible alternatives might include:

Line Stopping: This involves inserting a temporary plug into the pipeline to stop the flow of material while work is carried out. This requires a certain level of pipeline redundancy to reroute the flow around the work area.

Gas Bagging Off: This technique is typically used on low pressure gas pipework below 200mb pressure and 300mm and under diameter, it involves inserting an inflatable bag (or "plug") into the pipeline and inflating it to stop the flow of gas. This creates an isolated section where work can be carried out without having to shut down the entire system. 

Squeeze Off: This method is commonly used on MDPE pipelines, such as those used in the gas industry. It involves compressing the pipe at a certain point to stop the flow of material. Special tools are used to apply even pressure around the pipe and avoid damaging it. Once the squeeze-off is complete, work can be carried out on the isolated section of the pipe. After the work is done, the pressure is released, and the pipe returns to its original shape, allowing the material to flow again.

Complete System Shutdown: In some cases, it may be necessary to completely shut down the system in order to carry out the necessary work. This is generally the least desirable option due to the downtime and potential costs involved.

We have used Ormond's hot tapping services for over 20 years, and will continue to do so

Richard Milner
South Yorkshire Mechanical, on behalf of Barnsley Hospital

Ormond Pipework made my job easy and I would highly recommend them

Anna Page
Great Bear Distributions

Ormond have done our hot tapping for the last 10 years, we trust them to always get the job done.

Jamie Griffin
Webber N.W Ltd Chief Engineer, on behalf of Jaguar Land Rover

Very professional. We choose Ormond every time for our pipework.

Pete Woodall
Smart Tec Solutions, on behalf of M&S
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