Have you ever wondered how engineers can add new connections to water pipes, gas lines, or heating systems without turning them off? The answer is a clever technique called hot tapping. This process lets workers safely drill into pipes that are still carrying fluids under pressure, making it possible to add new branches or connections without causing any disruption.
In this guide, we’ll explain exactly how hot tapping works, why it’s so useful, and how professionals carry out this important job safely.
What Is Hot Tapping?
Hot tapping, also known as pressure tapping or under-pressure drilling, is a way of connecting to an existing pipe whilst it’s still in use. The pipe doesn’t need to be emptied, and the flow of whatever is inside (water, gas, or other fluids) continues normally throughout the entire process.
Think of it like adding a new branch to a tree whilst the sap is still flowing through it. The tree keeps growing, and the new branch becomes part of the system without any interruption.
This technique is used in homes, businesses, hospitals, shopping centres, and industrial facilities across the UK. Whenever someone needs to add a new connection to an existing pipeline system, hot tapping provides a fast, safe, and cost-effective solution.
Why Do We Need Hot Tapping?
Traditionally, if you wanted to add a connection to a pipe, you’d need to:
- Stop the system
- Drain all the fluid out
- Cut the pipe open
- Install the new connection
- Fill the system back up
- Restart everything
This process takes time and money. For a hospital, factory, or large building, shutting down the water or heating system for even a few hours can cause serious problems and cost thousands of pounds in lost productivity.
Hot tapping solves this problem by letting engineers work on the pipe whilst it stays active. This means no downtime, no disruption, and much lower costs.
How Does the Hot Tapping Process Work?
The hot tapping process follows a careful sequence of steps to ensure safety and success. Here’s how it works:
Step 1: Planning and Preparation
Before any work begins, engineers carefully plan the job. They need to know:
- What type of pipe material are they working with (steel, copper, plastic, etc.)
- What’s flowing through the pipe (water, gas, oil, or chemicals)
- The pressure inside the pipe
- The temperature of the contents
- The exact location for the new connection
This information helps them choose the right equipment and follow the correct safety procedures.
Step 2: Setting Up the Equipment
The team brings a special hot tapping machine to the site. This machine consists of several parts:
- A valve that attaches to the pipe
- A drilling machine that sits on top of the valve
- A cutting tool designed for the specific pipe material
- Safety equipment to control the process
The valve is securely attached to the pipe using strong clamps or welding, depending on the situation. This valve creates a sealed chamber between the pipe and the drilling machine.
Step 3: Making the Connection
Once everything is set up and checked, the actual drilling begins:
- The drilling tool passes through the valve and starts cutting into the pipe wall
- The cutting continues until it breaks through into the pipe’s interior
- The fluid inside the pipe stays contained within the valve chamber
- A small disc of metal (called a coupon) is cut out from the pipe wall
- The coupon is safely removed through the valve system
- The new connection is now complete
Throughout this process, the fluid continues flowing through the pipe normally. The valve controls everything, ensuring no leaks occur.
Step 4: Finishing Up
After the hole is made, engineers can:
- Attach a new branch pipe for additional connections
- Install monitoring equipment
- Add control valves
- Connect new sections to the system
The drilling machine is then removed, and the valve is left in place as a permanent part of the system.
Equipment Used in Hot Tapping
Hot tapping requires specialised tools designed to work safely under pressure. Here’s what professionals use:
| Equipment | Purpose | Key Features |
|---|---|---|
| Hot Tapping Machine | Creates a hole in the pipe | Handles high pressure, precise cutting control |
| Gate Valve | Seals the work area | Allows safe drilling, controls flow |
| Cutting Tools | Cuts through pipe material | Different designs for steel, plastic, and copper |
| Fittings and Flanges | Connects the machine to the pipe | Creates a secure, leak-proof seal |
| Safety Monitoring | Checks pressure and flow | Ensures safe operating conditions |
Modern hot tapping equipment is designed to work on many different types of pipes:
- Metal pipes: Stainless steel, carbon steel, copper, cast iron
- Plastic pipes: MDPE, PVC, and other polymers
- Concrete pipes: Reinforced concrete and cement
- Specialist materials: GRP (glass-reinforced plastic) and GRE (glass-reinforced epoxy)
When Is Hot Tapping Used?
Hot tapping is extremely useful in many situations:
In Commercial Buildings
- Adding new water connections to growing office buildings
- Extending heating systems without disrupting workers
- Installing new sprinkler systems for fire safety
- Upgrading plumbing in hotels and restaurants
In Industrial Settings
- Connecting new equipment to existing pipelines
- Adding monitoring points to check flow and pressure
- Creating bypass systems for maintenance
- Expanding production facilities
In Public Facilities
- Upgrading water systems in hospitals (where shutdowns are dangerous)
- Improving heating in schools during term time
- Extending gas supplies to shopping centres
- Maintaining services in care homes
Emergency Repairs
Sometimes hot tapping helps fix problems quickly:
- Isolating damaged sections of pipe
- Creating temporary bypasses
- Installing emergency shut-off valves
- Maintaining service during repairs
The Benefits of Hot Tapping
Hot tapping offers several important advantages:
No Downtime
The biggest benefit is that systems keep running. A hospital doesn’t lose its water supply. A factory keeps producing. An office building stays comfortable. This continuity saves enormous amounts of money and prevents serious problems.
Cost Savings
Without the need to shut down and restart systems, hot tapping saves costs in several ways:
- No lost productivity or business interruption
- No need to drain and refill systems
- Fewer labour hours required
- Less waste of valuable fluids
Faster Completion
Hot tapping jobs can be completed in hours rather than days. The team arrives, sets up, makes the connection, and leaves. There’s no waiting for systems to drain or refill.
Safer Operations
Working on drained, depressurised systems can sometimes be more dangerous than it seems. Hot tapping keeps everything controlled and contained, with multiple safety systems in place.
Environmental Benefits
By keeping fluids in the pipes, hot tapping prevents waste. Nothing needs to be drained out and disposed of, which is especially important for expensive or hazardous materials.
Safety in Hot Tapping
Safety is absolutely critical in hot tapping work. Professional companies follow strict rules to protect their workers and your property.
Following Regulations
In the UK, all pipeline work must comply with health and safety regulations. The Health and Safety Executive’s Pipelines Safety Regulations 1996 sets out the legal requirements for working on pipes that carry fluids under pressure. These regulations ensure that all work is properly planned, executed by trained professionals, and carried out with appropriate safety measures.
Professional Training
Hot tapping isn’t a job for amateurs. It requires:
- Specialist training and certification
- Years of practical experience
- Knowledge of different pipe materials and systems
- Understanding of pressure dynamics and fluid behaviour
Safety Equipment
Professional hot tapping teams use multiple safety systems:
- Pressure monitoring equipment
- Emergency shut-off valves
- Protective clothing and gear
- Gas detection equipment (when working with gas lines)
- Fire prevention systems
Risk Assessment
Before every job, engineers carry out a thorough risk assessment. They identify potential hazards and put controls in place to prevent accidents.
What Types of Pipes Can Be Hot Tapped?
One of the great advantages of modern hot tapping is its versatility. The technique works on:
Pressurised Pipes
Hot tapping is specifically designed for pipes under pressure. The equipment handles:
- Low-pressure systems (like domestic water supplies)
- Medium-pressure systems (heating and cooling)
- High-pressure systems (industrial processes)
Different Sizes
From small domestic pipes to large industrial pipelines, hot tapping equipment comes in various sizes. Teams can work on pipes from just a few centimetres across to several metres in diameter.
Various Contents
Hot tapping works with many different fluids:
- Clean water
- Wastewater
- Natural gas
- Heating oil
- Industrial chemicals
- Steam
- Compressed air
Choosing Professional Hot Tapping Services
If you need hot tapping work done, it’s essential to choose experienced professionals. Here’s what to look for:
Experience and Expertise
Look for companies with a proven track record. At RDS Pipeline Isolation, we’ve been providing specialist pipeline services for over 20 years. Our team has worked on countless projects across the UK, from small domestic jobs to major industrial installations.
Proper Equipment
Professional companies invest in high-quality, well-maintained equipment. This ensures safe, reliable work every time.
Comprehensive Insurance
Any company working on your pipes should carry full insurance cover. This protects you if anything goes wrong.
Good Communication
The best professionals explain the work clearly, keep you informed throughout the process, and answer all your questions.
The Future of Hot Tapping
As our infrastructure ages and our systems become more complex, hot tapping becomes increasingly important. New developments in the technology include:
- More precise cutting systems
- Better safety monitoring
- Equipment for new pipe materials
- Automated systems for routine jobs
This means hot tapping will continue to be a vital technique for maintaining and improving our pipeline systems without disruption.
Conclusion
Hot tapping is a clever engineering solution that allows new connections to be made to existing pipes whilst they remain in use. By using specialist equipment and following strict safety procedures, trained professionals can drill into pressurised pipes without causing leaks, downtime, or disruption.
Whether you’re managing a commercial building, running an industrial facility, or maintaining public infrastructure, hot tapping offers a fast, safe, and cost-effective way to adapt your pipeline systems to changing needs.
If you need hot tapping services or want to learn more about how this technique could help your project, contact RDS Pipeline Isolation on 01277 500510. With over 20 years of experience serving clients across Essex and throughout the UK, we’re here to provide expert advice and professional service for all your pipeline isolation needs.
