Design Specification for Engineering of Telecommunications Network Management System

Author: None
Publisher: Beijing University of Posts and Telecommunications Press
Publication Date: 1998-01-01
Features:
Section 4: Laying and Installation of Plastic Pipes
4.0.1 The burial depth of plastic pipes shall comply with design requirements.
4.0.2 The specifications, sizes, and lengths of plastic pipes shall meet design specifications.
4.0.3 Plastic pipes shall be laid manually, and the installation shall comply with the following regulations:
1. Before laying plastic pipes, the pipe ends shall be blocked with sealing plugs.
2. The bottom of the trench for plastic pipes shall be flat and straight, with smooth transitions at trench shoulders and corners.
3. When encountering a stony trench bottom, 100 mm thick crushed stone or sand shall be laid above and below the plastic pipes.
4. After laying plastic pipes, they shall be sealed promptly. Pipes leading to manholes shall be promptly sealed at the ends.
5. The fixing of plastic pipes in the trench shall be carried out in accordance with design requirements.
6. When multiple plastic pipes are laid in the same trench in the same area, their arrangement and colors shall comply with design specifications.
7. To ensure the connection of auxiliary plastic pipes during air-laid optical cable installation, the excess length of the plastic pipe ends at manholes shall be approximately 300 mm.
8. Plastic pipes laid on the bottom of rivers or shall be laid as a single continuous piece without joints.
9. When burying underwater plastic pipes using the compression method, the plastic pipes shall not bend or float on the trench bottom.
4.0.4 Backfilling shall comply with the following regulations:
1. Backfilling shall only be carried out after the plastic pipes have been inspected and confirmed to meet quality standards.
2. First, backfill 10 mm thick fine soil or broken soil.
3. The backfilled soil shall be at least 100 mm higher than the ground level.
4. In urban areas, when excavating trenches to cross roads and backfilling, the relevant provisions of the Ministry's standard YDJ39-90 "Technical Specifications for Construction and Acceptance of Telecommunication Cable Trenches" shall be followed.
4.0.5 Plastic pipe joints shall meet the following requirements:
1. The positions of plastic pipe joints shall be marked on the construction drawings.
2. The joint cross-section of plastic pipes shall be flat and free of burrs.
3. The specifications and sizes of for plastic pipes shall comply with design requirements. If metal splicing components are used, they shall be treated with heat-shrinkable waterproof sleeves.
4. During the splicing process, prevent mud, sand, water, and other debris from entering the plastic pipes.
5. If plastic pipes cannot be spliced promptly during laying, they shall be overlapped by 100 mm.
6. After assembling plastic pipes and connecting components, perform an airtightness test by inflating to 0.1 MPa and ensuring that the pressure drop within 24 hours does not exceed 0.01 MPa.
4.0.6 Protection of plastic pipes shall comply with the following regulations:
1. The protective measures for plastic pipe trenches shall comply with design requirements and shall follow the direct burial optical cable provisions in the Ministry's standard YDJ44-89 "Provisional Technical Specifications for Construction and Acceptance of Optical Fiber Digital Transmission Systems in Telecommunication Networks."
2. The setting of markers shall comply with the relevant provisions of the Ministry's standard YDJ44-89 "Provisional Technical Specifications for Construction and Acceptance of Optical Fiber Digital Transmission Systems in Telecommunication Networks."
3. Additional ordinary markers shall be installed at plastic pipe joints. The marker markings shall be 07 (H) 23.
Note: The numerator of the number indicates the serial number of the plastic pipe joint, and the denominator indicates the total number of markers within a repeater section.
4.0.7 The construction specifications of manholes shall comply with design requirements.
4.0.8 The ends of plastic pipes inside manholes shall be airtightly sealed.