Installation of External Pipes for Mobile Toilets

The installation of external pipes for mobile toilets should be carried out in accordance with the following steps to ensure the safe and efficient operation of the drainage system:

1. Determine the Drainage Location and Slope Select an area closest to the bottom of the toilet and convenient for connecting to the municipal sewer network as the drainage outlet. The slope should be ≥2% (a drop of 2 cm per meter) to ensure the self-flow of sewage. If ground conditions are limited, adjust the slope by raising or lowering the ground to prevent sewage retention due to insufficient slope.

2. Pipe Laying and Connection

• Pipe Material Selection: Prioritize the use of PVC-U pipes (with an outer diameter of 110 mm and an inner diameter of 103 mm), which are corrosion-resistant and cost-effective.
• Connection Method: Use a bell-and-spigot connection, applying special glue at the joint and adding a rubber ring for sealing to prevent leakage. When connecting the sewer pipe, ensure that the joint size matches the pipe material, and extend the other end along the ground to the drainage outlet.
• Elbow Usage: Avoid sharp right-angle turns and must use 45° elbows for transitions to reduce water flow resistance and prevent backflow.

3. Anti-Seepage and Sealing Treatment

• Waterproof Flange Installation: Install a waterproof flange at the junction of the pipe and the toilet base, and fill the gap with weather-resistant sealant to prevent sewage from seeping out from the joint.
• Joint Sealing: Apply sealant evenly at the joint of the sewer pipe and press it tightly to ensure a seamless connection. The sealing material should be water-resistant and corrosion-resistant to adapt to long-term use conditions.

4. Maintain Pipe Angle and Stability

• Vertical or Horizontal Installation: The sewer pipe should be kept vertical or horizontal. Excessive inclination can lead to poor drainage.
• Fixed Support: For long-distance laying, install fixed supports every 1.5-2 meters to prevent pipe deformation due to gravity or external forces.

5. System Testing and Acceptance

• Water Injection Pressure Test: After installation, fill the pipe with water to its full capacity and observe for 24 hours. No leakage indicates acceptance.
• Flow Velocity Detection: The drainage flow velocity should be ≥0.6 m/s, which can be verified by timing the drainage volume. Insufficient flow velocity can easily cause sedimentation and blockage.

6. Special Environment Treatment

• Winter Frost Protection: In northern regions, wrap the pipe with an insulation layer (such as rubber-plastic sponge) to prevent pipe brittleness due to low temperatures.
• Use of Offset Connectors: If the toilet position needs to be adjusted, install an offset connector before laying the floor tiles and ensure that the drainage slope increases with distance (e.g., a slope of ≥3% for a 1-meter distance). However, note that offset connectors may increase the risk of blockage, and a direct drainage layout is recommended whenever possible.

Precautions: Close the water source and empty the pipe before construction to prevent debris from entering; clean the site after installation to ensure the drainage outlet is unobstructed. If connecting to the municipal sewer network, report to the relevant department in advance and comply with regulations.