Hot tapping is usually the better option when a new connection or access point is required and interrupting the pipeline would create unacceptable operational, financial or customer consequences. It allows the main pipeline to remain pressurised and in service while the connection is created.
A full shutdown may still be the correct choice when the pipe is unsuitable for hot tapping, the work requires unrestricted access to the pipe interior or the planned modification cannot be completed safely using under-pressure methods.
The decision should therefore be based on more than downtime alone. Pipeline condition, material, pressure, temperature, connection size, worksite access and the total cost of an interruption must all be assessed.
If you are comparing these options for an upcoming project, send Tonisco your pipeline details. We can assess the application and recommend hot tapping, line stopping or a planned shutdown.
What is the difference between hot tapping and a full shutdown?
Hot tapping creates an opening or branch connection on a live pipeline. A fitting and valve are installed on the main before a sealed tapping machine cuts through the pipe wall. The cutter and removed section of pipe wall are then retracted, and the valve is closed before the machine is removed.
The main pipeline can remain operational during this process, subject to the approved working procedure and operating conditions.
A conventional shutdown follows a different sequence. The affected pipeline section must normally be isolated, depressurised and drained before the modification begins. After the work has been completed, the section must be refilled, vented, checked and returned to operation.
| Decision factor | Hot tapping | Planned pipeline shutdown |
|---|---|---|
| Main pipeline operation | Normally remains pressurised and in service | Affected section is taken out of service |
| Draining and refilling | Normally not required for the main pipeline | Commonly required |
| Customer interruption | Can often be avoided | Usually requires an agreed outage |
| Treated water or medium loss | Limited | May be considerable |
| Heat and energy loss | Reduced by keeping the system operational | Cooling and reheating may be required |
| Scheduling | Less dependent on an outage window | Requires coordinated isolation and restart |
| Suitable work | Branches, instrument connections and access points | Extensive internal or structural work |
| Engineering requirements | Specialist live-line assessment | Isolation, drainage and recommissioning plan |
Neither method is automatically correct for every project. The aim is to select the safest and most commercially sensible method for the actual pipeline and required modification.
For a detailed explanation of the equipment and process, read our guide to what hot tapping is and how it works.
Choose hot tapping when service continuity matters
Hot tapping is particularly valuable when the main pipeline serves customers or processes that should not be interrupted. In district heating and cooling networks, an outage can affect residential properties, businesses, public buildings and other connected facilities.
Avoiding a shutdown can also remove several additional stages from the project:
Coordinating an outage with affected customers
Draining treated network water
Arranging for the disposal or storage of the drained medium
Refilling and venting the system
Reheating the affected network section
Checking and recommissioning the system after restart
The value of avoiding these stages increases with the size of the network and the number of customers or processes affected.
Hot tapping is therefore worth considering when:
A new building or network section must be connected
A branch is needed for future network expansion
A pressure, temperature or sampling point must be installed
A valve, vent or drain connection is required
Access points are needed for line stopping
A temporary bypass is being prepared
A shutdown would interrupt an important production process
Draining and refilling would consume significant time, energy or treated medium
Work must be completed outside the normal shutdown season
Do you already know the required connection size? Request a hot tapping assessment from Tonisco and include the main pipe size, material, wall thickness, pressure and temperature. This information allows us to evaluate the application and prepare a budgetary quotation.
When is a full shutdown the better option?
Hot tapping is not a substitute for every pipeline maintenance method. A full or local shutdown may be necessary when the pipe cannot safely support the fitting and cutting operation or when the required work extends beyond creating a controlled connection.
A shutdown may be the more appropriate choice when:
The pipe has severe corrosion, cracking or other damage at the proposed connection point
The remaining wall thickness is inadequate
The pipe material or medium is incompatible with the proposed fitting or joining method
Reliable information about the pipe material or operating conditions is unavailable
Suitable pressure-rated equipment cannot be configured for the application
The work requires extensive access to the inside of the pipeline
A long pipe section must be removed or completely replaced
The pipeline can already be isolated locally without causing a significant service interruption
Site access does not provide enough space for safe equipment installation and operation
A professional assessment should be completed before deciding that hot tapping is feasible. If the pipe condition is uncertain, additional inspection or measurement may be required.
At Tonisco, our goal is not to recommend hot tapping at any cost. We determine whether it is technically suitable and whether it provides a genuine operational or commercial advantage over the available alternatives.
What does a shutdown really cost?
The direct price of the pipeline work is only one part of the decision. A meaningful comparison should include the complete cost and operational effect of each method.
Depending on the network, shutdown-related costs can include:
Planning and coordinating the interruption
Customer communications
Temporary heating or production arrangements
Lost production or service capacity
Labour required for isolation, drainage and restart
Disposal or treatment of the drained medium
Replacement water and water-treatment chemicals
Energy required to reheat the network
Additional testing and recommissioning
The operational risk associated with restarting the system
Hot tapping requires specialist equipment, planning and trained personnel, but it may avoid many of these shutdown costs. The financial advantage is greatest when the affected network is large, the operating medium is valuable or an interruption would affect critical customers or production.
The comparison remains project-specific. Hot tapping should not be described as automatically cheaper, but it can produce substantial overall savings when the true cost of an outage is included.
Contact our team for a project-specific comparison. We can help you evaluate the required connection alongside the operational consequences of a shutdown.
Can hot tapping be used for emergency repairs?
Hot tapping can support an urgent repair strategy, but it is not itself a universal leak-repair method.
The technique creates a controlled opening or access point. That opening may then be used to install a branch, prepare a bypass or provide access for line stopping. Repairing or replacing the damaged section may require additional equipment and a temporary isolation plan.
For example, Tonisco can use hot tapping to create the access points required for line stopping. The affected section can then be isolated and drained while the remainder of the network stays in operation.
The correct response to a leak depends on:
The location and type of damage
Pipe material and condition
Leak severity
Operating pressure and temperature
Available valves and isolation points
Space around the pipeline
Whether a bypass is required
The repair or replacement method
If you have an active pipeline problem, contact Tonisco Service with the available pipeline and site information. We can evaluate which under-pressure method is suitable instead of assuming that hot tapping alone will solve the problem.
When do you need line stopping as well as hot tapping?
Hot tapping and line stopping perform different functions.
Hot tapping creates an opening in the live pipeline. Line stopping uses a hot-tapped opening to insert a temporary plugging head and restrict flow.
Line stopping is used when the work area must be isolated but shutting down the entire network is undesirable. Common applications include valve replacement, pipe-section repair, pipeline relocation and the installation of inline components.
Tonisco offers two principal approaches for district heating and cooling networks:
Single Stop: the pipeline is temporarily plugged from one point. The secured section is then drained before the repair or modification begins.
Double Stop: the line is plugged from two points and the section between the plugs is drained. A temporary bypass can be installed between the line stop machines when service must continue around the isolated section.
Double Stop is not automatically the best or most economical choice. The appropriate method depends on the network configuration, direction of flow, required isolation, acceptable interruption and need for a bypass.
Learn more about our line stopping services for heating and cooling networks, or ask our service team to assess the complete operation.
What technical factors determine whether hot tapping is possible?
Before selecting hot tapping, the complete pressure-containing setup must be assessed. This includes the pipe, fitting, valve, adapters, cutter and tapping machine.
The essential project information includes:
Main pipeline size and material
Actual pipe wall thickness
Pipe condition at the proposed connection point
Design pressure and temperature
Current operating pressure and temperature
Pipeline medium
Required branch size and pressure class
Proposed fitting and valve type
Available space around the pipeline
Excavation dimensions for underground work
Worksite access and lifting requirements
Whether electric tools are permitted
Applicable local requirements and standards
Tonisco Service uses different fitting methods according to the pipeline material. Common solutions include welded reinforcement plates or weldolets for steel pipelines, fusion-welded saddles for PE pipelines and mechanical hot tap clamps for other materials.
Our published Basic Hot Tapping Service capability covers sizes from DN10 to DN1600. The published operational limits include a maximum pressure of 60 bar at 40 °C and a maximum temperature of 200 °C at 16 bar.
These values describe different operating points and must not be combined. Actual feasibility depends on the complete equipment configuration, pipe material, medium and site conditions.
Hot tapping equipment for in-house teams
Tonisco can provide a complete service or supply equipment for qualified organisations that perform their own hot tapping work.
For medium-sized connections, the TONISCO B30 Hot Tap Machine – E covers hot tap sizes from DN40 to DN200. Its published specifications include a maximum pressure of 60 bar and a maximum temperature of 200 °C. With suitable adapters, it can be used with threaded, weldable or flanged connections.
The complete setup still needs to be selected for the actual operating conditions. Machine limits do not replace verification of the valve, fitting, cutter, adapters and other pressure-containing components.
If you are building or updating an in-house hot tapping setup, request a quote for the TONISCO B30 or contact our sales team for help selecting the machine, cutters, adapters, valves and drive units required for your work.
Why choose Tonisco for under-pressure pipeline work?
Tonisco is a Finnish family-owned company founded in 1969. Tonisco System manufactures hot tapping and line stopping products, while Tonisco Service performs under-pressure pipeline work for customers in more than 20 countries.
This combination gives our customers access to both equipment expertise and practical project experience.
We can support your organisation with:
Project assessment and method selection
Equipment and component recommendations
Hot tapping machines, valves, cutters and adapters
New branch connections
Instrument and sensor connections
Access points for line stopping
Single Stop and Double Stop solutions
Temporary bypass arrangements
Cooperation with your own contractors
Turnkey planning and on-site execution
Whether you require one branch connection or a more complex network modification, we can define a solution around your operating conditions and service-continuity requirements.
Request an assessment for your pipeline
To receive an initial assessment and budgetary quotation, send us:
Main pipeline size and material
Pipe wall thickness
Design pressure and temperature
Current operating pressure and temperature
Required connection size and pressure class
Site location and access information
Photographs or drawings of the proposed work area
Your preferred project schedule
Request a hot tapping assessment and our team will evaluate whether hot tapping is suitable, whether line stopping is also required and which equipment or service package fits the project.
You can also review our professional hot tapping services before contacting us. We provide equipment, technical support and turnkey execution for modifications that need to be completed while your network remains in operation.