Characteristics:
1、Working Pressure and External Load: PCCP pipes can withstand high working pressures and external loads simultaneously. PCCP has a sturdy concrete core and uses a hydrostatically tested steel cylinder embedded within the core. Due to the application of prestressing technology in its design and manufacturing, which fully utilizes the tensile strength of the prestressing wires and the compressive strength of the core concrete, PCCP can withstand both high working pressures and high external loads, which is unattainable by pipes made of other materials. The standard specifies a withstandable pressure range of 0.4 to 2.0 MPa.
2、Impermeability and Sealing: PCCP relies on the steel cylinder embedded in the concrete core, which has passed hydrostatic tests, to provide impermeability, solving the seepage problems common in other pipes and thus ensuring PCCP's impermeability. The pipe joints use push-on/spigot-type rubber gaskets for sliding flexible seals. The bell and spigot rings welded to both ends of the steel cylinder are manufactured using metal cold-working processes, ensuring precise dimensions with tolerances within 0.2mm. After the sealing rubber gasket is engaged with the bell and spigot within the specially designed gasket groove, the gasket is compressed on three sides, guaranteeing joint sealing.
3、Corrosion Resistance and Durability: PCCP has a sturdy concrete core and an outer, tough mortar coating. In use, due to the properties of concrete, its strength and hardness often increase with age. From its structure, the reliability mechanism of PCCP is evident: the steel cylinder is encased in concrete, the high-strength wires are protected by the cement grout and mortar coating. After the PCCP bell and spigot are installed, the exposed parts are grouted with cement mortar, thus naturally receiving alkaline protection from the free lime in the cement.
4、Environmental Adaptability and Seismic Resistance: The PCCP pipe body is rigid, but the joints use flexible bell-and-spigot rubber gasket interfaces, providing significant flexibility. Its joints can rotate a certain angle, thus offering strong resistance to uneven settlement, low foundation requirements, and excellent seismic performance. Its ability to adapt to ground changes is better than other pipe materials. Example: After the magnitude 7.3 earthquake in Jiji, Taiwan, China, on September 21, 1999, an investigation showed that all other pipes like SP, DIP, PVC suffered varying damage,唯独PCCP remained undamaged. The dedicated PCCP lines for the Taiwan Six Light petrochemical project, totaling 86km within 50km of the epicenter, were unharmed.
5、Flow Resistance: The PCCP core concrete is formed using the steel thin-wall vibration production process. Under the vibration of high-frequency vibrators, the frequency is evenly transmitted along the thin inner and outer steel molds, resulting in a very smooth concrete surface, good water flow inside the pipe, and low friction resistance. Simultaneously, the smooth inner surface prevents tuberculation, ensuring unimpeded water flow. The roughness coefficient is 0.013.
6、Long Service Life: The design service life of PCCP is not less than 50 years. Scientific论证 indicates that when lime moistens, it produces calcium hydroxide. The high alkalinity (pH up to 12.5) of cement creates a passivating oxide layer on the steel, resisting soil corrosion and extending service life. For example: PCCP produced in 1943 by LockJoint and Price Brothers is still in use (over 74 years). A 1620mm diameter, 126km pipeline from Saginaw to Midland, Michigan, installed in 1947, is still operational (over 70 years). Studies involving examination of PCCP with service lives up to 60 years conclude that the mortar coating remains in good condition, effectively preventing wire corrosion, and design life can be set at 75 years or more with potential for even longer life. Some assessments suggest PCCP lifespan can exceed 100 years.
7、Construction Comparison: PCCP installation is fast, requires no special bedding, and allows backfilling with native soil. Joints can be pressure tested immediately after installation, allowing quick backfill and facilitating overall pipeline testing, accelerating progress and saving over 98% of water compared to other methods. Ordinary pipes often require multiple pressure tests. PCCP's steel joint with confined sliding gasket (98% constrained) provides excellent sealing under bidirectional compression after installation.
8、Operation and Management Analysis: Due to its high resistance to external pressure, PCCP has much lower requirements for foundation and backfill compared to flexible pipes, resulting in lower installation costs than steel pipe, ductile iron pipe, and plastic pipe. PCCP's excellent corrosion resistance, impermeability, and durability lead to a long service life and the lowest maintenance costs among various pipes, virtually zero.
Key Application Fields:
Urban water supply and drainage mains, industrial water transmission pipelines, agricultural irrigation, power plant pipelines, power plant make-up water and cooling water circulation systems, inverted siphons, pressure tunnels, pipe trenches, utility tunnels, and buried pipe culverts, etc.
Company's Current Key Technological Innovation Points:
RFID-based PCCP Information Management Platform
The main function involves embedding one passive UHF RFID tag in both the bell and spigot ends of each PCCP pipe, with capability to upgrade to active UHF RFID. It enables informatized and intelligent management and control of PCCP from raw materials, production process, installation, to operation and maintenance. After pipeline installation, RFID connects with the PCCP monitoring network (prestressing wire monitoring, stress monitoring, full lifecycle detection, pipeline settlement, flow rate, etc.), achieving full lifecycle management of PCCP pipelines. The system uses a B/S architecture and cloud services. Data security is ensured via data encryption, firewalls, data security fortresses, or classified protection certification.
Patents Owned:
The company currently holds 151 utility model patents and 9 invention patents related to PCCP. It has participated in national key scientific research projects and won first and second prizes for scientific and technological progress. Projects involving the company's PCCP, like the Wanjiazhai Yellow River Diversion Project North Main Trunk Line, have received honors such as the 11th Zhan Tianyou Award for Chinese Civil Engineering.
