Application of PE pipe construction technology

Application of PE pipe construction technology

PE (polyethylene) pipes are widely used in agricultural irrigation, municipal water supply and drainage, etc. due to their corrosion resistance, good flexibility and convenient construction. The following are the detailed steps, technical points and precautions for PE pipe construction, covering key links such as excavation, hot melt connection and laying.

Site survey and route planning • Pipeline detection: When constructing in urban areas, use pipeline detectors (such as GPR geological radar) to locate existing underground pipelines (cables, gas pipes, drainage pipes, etc.) to avoid damage during construction. • Geological analysis: Adjust the excavation method according to the soil type (such as sand, clay, rock). A crusher or directional drill is required for the rock layer, and the slopes of soft soil need to be reinforced. • Burial depth design: • Agricultural irrigation: The general burial depth is 0.6-1.2 meters (≥1.5 meters is required for frost protection in cold northern regions). • Municipal engineering: Determine the burial depth according to the road grade (≥0.9 meters under the carriageway, ≥0.6 meters under the sidewalk).

Trench excavation and treatment • Size requirements: The trench width should be the outer diameter of the pipeline + 0.3-0.5 meters (such as the trench width of a Φ110mm pipeline ≥ 160mm), and the depth error should be ≤ ±5cm. • Bottom treatment: Lay a 10-15cm thick fine sand or gravel cushion layer to ensure that the pipeline foundation is flat; if a rock layer is encountered, a soft soil layer needs to be added for buffering. • Environmental protection: Excavated soil is classified and stacked, and the topsoil is separated from impurities. When backfilling, the topsoil should be restored first.

PE pipe hot melt connection technology

PE pipe hot melt connection is divided into hot melt butt welding and hot melt socket welding, which are suitable for different pipe diameters and scenarios. The following is the detailed operation process of hot melt butt welding: 1. Hot melt butt welding steps 1. Material and tool preparation • Hot melt machine: Select a hot melt machine that matches the pipe diameter (such as a Φ110mm pipe requires a 110mm hot melt machine), and check whether the heating plate temperature is stable at 210±10℃. • Auxiliary tools: pipe cutter, scraper, cleaning cloth, straightening clamp, etc.

Pipe cutting and end surface treatment • Cutting: Use a rotary pipe cutter or electric cutter to cut the pipe vertically, ensuring that the end surface is flat (error ≤ 0.5mm), without burrs and cracks. • Cleaning: Wipe the end surface with alcohol or acetone to remove oil and dust. • Straightening: Align the two sections of pipe and use a straightening fixture to eliminate the gap (gap ≤ 0.3mm

3. Hot-melt butt welding operation • Heating: Insert the heating plate into the pipe end face, and the heating time is calculated according to the formula:

is the pipe diameter, unit

(e.g. the heating time of a Φ110mm pipe is ≈ 13.85 seconds). • Melting: After heating is completed, quickly withdraw the heating plate, fit the pipe end faces, and maintain the axial pressure in the molten state (0.15-0.2MPa). • Cooling: Cool to ambient temperature (usually 10-15 minutes), and it is strictly forbidden to move the pipe during cooling.

4. Quality Inspection • Appearance inspection: The weld should be uniform and full, without bubbles or cracks, and the misalignment should be ≤10% of the pipe wall thickness. • Tensile test (optional): Destructive test of key parts to ensure that the welding strength is ≥90% of the parent material.

2. Hot melt socket welding steps are suitable for small diameter (≤Φ63mm) connections, and the operation is simpler: 1. Preparation: Heat the socket end to 220±10℃, and apply special lubricant to the spigot end to reduce friction. 2. Insertion: After heating, quickly insert the spigot into the socket to the marked line, hold for 5-10 seconds, and then cool to shape.

Pipeline laying and fixing

Pipeline laying• Laying in sections: Place the hot-melt connected pipe sections in sequence into the groove to avoid scratches caused by dragging. • Flexible laying: Use the flexibility of PE pipes to bend naturally to bypass obstacles (bending radius ≥ 5 times the pipe diameter). • Support measures: Set concrete piers or U-shaped clips to fix at stress concentration points such as elbows and tees.

2. Backfill and compaction • Layered backfill: First backfill with fine sand or graded gravel to 30cm from the top of the pipe, then compact in layers (one layer every 30cm) to avoid direct trampling. • Warning signs: Bury warning tape or electronic marking tape above the pipe to mark the location and purpose of the pipe.