T/SGX 007-2019 Core-foamed hard polyvinyl chloride (PVC-U) pipes for underground communication pipelines

Scope

Main technical content: 1. Ring stiffness: Divided into five grades (SN4, SN6.3, SN8, SN10, SN12.5), ensuring resistance to lateral pressure from backfill soil during underground installation and providing a basis for selecting compression resistance parameters for design. 2. Apparent density: 0.9–1.2 g/cm3, reflecting the characteristics of the foam core pipe and ensuring a certain foam expansion rate. 3. Flatness test: When the deformation of the outer diameter in the vertical direction reaches 40% of the original outer diameter, there is no separation or cracking, ensuring the product's toughness and preventing damage to the pipe. 4. Recovery rate: After the pipe is subjected to a certain degree of compression, it recovers to 90% of its original state. 5. Drop hammer impact test: 10 impacts, with no breakage in 9 cases, ensuring a survival rate of over 90% after accidental impact. 6. Falling test: Ensuring no cracking occurs during accidental dropping during transportation or installation. 7. Longitudinal shrinkage rate: When the pipe is subjected to thermal expansion and contraction, the deformation should not exceed 9%. (These technical specifications refer to the national standard GB/T 16800-2008) 8. Sealing test: Sealing test of the connection joints to prevent water leakage.

Development Information

Related Standards