Installation techniques for welded steel pipes

When installing welded steel pipes, following precise techniques ensures that the piping system is both durable and efficient. Proper preparation and adherence to standard procedures are essential to prevent leaks, ensure alignment, and maintain the structural integrity of the piping system. Below is a detailed guide on the installation techniques for welded pipes.

1. Preparation for Welded Steel Pipe Installation

Before beginning the installation process, thorough preparation is crucial:

Equipment Check: Ensure that the drilling machine, grooving machine, and pipe cutting machine are in safe working condition.

Material and Tool Preparation: Gather all necessary materials and tools, including pipes, steel tapes, wrenches, vernier calipers, levels, lubricants, wooden hammers, and scaffolding.

Support and Hanger Installation: Install the pipeline supports and hangers according to the design specifications to provide stable and reliable support during the installation process.

2. Rolling Groove

Creating a precise rolling groove in the steel pipe is essential for proper joint connection:

Pipe Cutting: Use a pipe cutting machine to cut the steel pipe to the required length. Ensure the cut section is perpendicular to the central axis of the pipe by checking with a level. Smooth any burrs with a grinder.

Positioning the Pipe: Stand the pipe on the grooving machine, using a level to confirm it is in a horizontal position.

Grooving Process: Align the pipe with the grooving machine, ensuring the central axis is perpendicular to the roller surface. Gradually apply pressure with the jack, allowing the upper pressure wheel to groove the pipe to the required depth. Use a vernier caliper to check that the groove meets standard requirements before removing the pipe.

3. Opening Holes for Mechanical Tees and Crosses

Precise hole creation is necessary for the installation of mechanical tees and crosses:

Marking and Positioning: Mark the pipe with an ink line to indicate the opening position for the joint branch pipe.

Drilling: Secure the chain drilling machine at the marked location, start the motor, and slowly advance the drill bit towards the pipe while adding lubricant to protect the drill. Once the hole is made, clean the area and smooth the edges with a grinder.

Fitting Installation: Place the clamp on the pipe, ensuring the mechanical tee is centered over the hole. Tighten the fastening bolts evenly. For mechanical four-way connections, ensure both holes are concentric to prevent damage to the rubber sealing ring and maintain water flow efficiency.

4. Pipeline Installation

Follow a systematic approach to install pipelines to ensure proper alignment and function:

Order of Installation: Begin by installing large-diameter, main pipes, and risers, followed by smaller diameter and branch pipes. This sequential installation prevents difficulties in connecting segments and ensures the overall performance of the pipeline.

Pipe Connection: Fix the steel pipe onto the support and hanger, applying a non-destructive rubber sealing ring to one end. Insert the lubricated end of the next pipe into the sealing ring and align it centrally. Install clamps over the sealing ring, tightening bolts evenly while tapping with a wooden hammer to prevent wrinkling of the rubber seal.

Support Hanger Placement: Install a support hanger 500mm from the rigid clamp joint to provide additional stability.

5. System Pressure Testing

After completing the installation, conduct a system pressure test to ensure the integrity of the pipeline:

Pre-Test Inspection: Check that all mounting parts and fixing brackets are properly installed. If any pipe sections sag, add additional supports if necessary.

Pressure Test Execution: Gradually increase the pressure within the pipe. Minor sagging may correct itself as internal pressure rises, but large arcs should be addressed with additional support.

By carefully following these installation techniques, welded pipes can be installed with precision, ensuring a reliable and long-lasting piping system.