Steel Reinforced Polyethylene Corrugated Pipe Applications & Inspection Standards
17Pages

Steel Reinforced Polyethylene Corrugated Pipe Applications & Inspection Standards Sichuan Goldstone Orient New Material Equipment Inc. Mr. Han Hongtao, Sales Manager, Production R&D Thomas Hickey, Technical Consultant 2017.07 Abstract: Since 2004, Steel Reinforced Polyethylene Corrugated Pipe (SRPE) has been applied in sewage & drainage applications in China. Because of its superior stiffness and economic cost of production, SRPE has been widely used in large diameter sewage pipe applications, and has become a major sewage pipe system, offering an excellent substitute for concrete pipe. Following the broad success in China, this composite pipe technology has also been adopted outside of China in a number of highly industrialized countries, such as Italy, USA, Canada, Russia, Turkey and Israel. This innovative composite pipe technology is rapidly gaining recognition for its superior properties and economic costs in various applications and is acquiring acceptance in the marketplace. There are now many industry standards that have been issued by various countries and organizations including SII458， ASTM F 2435， CJ_T 225-2011， 11434 ITA， B182.14-15, UNI CSA etc. The standards provide the technical specifications and performance evaluation methods for the various applications of SRPE pipe. This paper will review some of the methods in these specifications and provide some clarification of the differences between them. Hopefully as more experience is gained and the technology advanced we will see this innovative composite pipe in other applications. Introduction： Steel Reinforced Polyethylene Corrugated Pipe (SRPE) had been applied in China since 2004. After more than a dozen years in commercial applications considerable experience has been gained in design, fabrication and installation practices. These experiences need to be studied and the knowledge gained included in future developments and applications to continue to improve SRPE and further its adoption worldwide. SRPE pipe employs a multilayer wall construction consisting of inner and outer polyethylene layers and an omega-shape steel profile bonded to the two polyethylene layers by an adhesive (fig.1). Such construction maintains the key properties of polyethylene pipes (low coefficient of friction, chemical resistance, lightweight, etc.) while also benefitting from the structural properties of steel (high stiffness). Compared to plastic pipe, the use of steel in SRPE pipe provides higher resistance to external loads but lower consumption in raw materials. This results in smaller outside diameters, lower total construction weight, smaller trench dimensions and significantly reduced installation costs. An added proven benefit of SRPE pipe is that it has better long-term performance characteristics such as creep under constant external

Fig. 1. The structure of SRPE: 1 – inner polyethelyne layer, 2 – adhesive, 3 – omega-shape steel profile, 4 – outer polyetheline layer Using the spiral wound pipe processing method combined with steel reinforcing technology, allows large inner diameter SRPE pipe to be produced up to 3000mm with pipe ring stiffness from SN8 to SN16, or even higher. While these stiffness numbers may seem incredible, SRPE composite pipe can typically obtain the desired stiffness quite easily by a combination of adjusting the thickness of steel reinforcement and the pitch of the steel ribs. Additional options...

SRPE Pipe Typical Applications Currently SRPE pipe technology is being applied in many countries besides China. Countries using the SRPE pipe technology include Japan, Italy, Russia, Israel, Turkey, USA, Canada, Thailand, Serbia, Romania, Ukraine, Azerbaijan… The various applications include: 1. Large diameter sewerage and drainage pipe system SRPE pipe shows many advantages when it is compared with other large diameter traditional civil sewerage pipe systems like concrete pipe, casting pipe and plastic pipe without reinforcement. The steel reinforcement allows the pipe to reach higher...

2. Stormwater drainage pipe system Large diameter SRPE pipe can provide cities greater ability to drain surface water runoff from heavy rainfalls. So as city areas and populations grow, the city planners are considering using larger and larger stormwater drain pipes. Traditional drainage pipes have some limitations when the size gets too big, but this innovative composite pipe provides a new solution. Due to the steel reinforced structure, the SRPE pipe can achieve high stiffness (> SN8) even on large diameters up to 3000mm. 3. Rainwater collection In some dry areas, perforated pipe is used...

4. Water collection system and wastewater treatment plant Another useful application of steel reinforced pipe is on water treatment stations and wastewater plants. There is a reference in Turkey for a hydraulic dam project where the SRPE pipe was used for branch pipes and venting. 5. Water storage tank The high strength, large diameter SRPE pipe reinforced by steel is a very good material for making water storage tanks. There are a number of projects finished in China and Thailand.

6. Low pressure irrigation pipe for agricultural Agricultural water delivery systems need an economic solution for low pressure large diameter pipe (2-4 bar). Solid wall polyethylene pipe can be used in this application, but due to the high pipe cost it is not typically employed for large agricultural areas. SRPE pipe may provide a new solution for these irrigation pipe systems. Currently, SRPE pipe with a thicker wall to withstand the internal pressures is under development for this application and reliable pipe connections for this low pressure pipe are in testing. 7. Culvert Culverts are...

SRPE Pipe Production Standards Various production standards have been developed and adopted for SRPE pipe. The following represent some of the key standards: ASTM F2435-15 (USA) Standard Specification for Steel Reinforced Polyethylene (PE) Corrugated Pipe CJ_T 225-2011 (China) Metal Reinforced Polyethylene (PE) Spiral Corrugated Pipe for Underground Sewer SII458 (Israel) Structure Wall Pipe of Steel Reinforced Polyethylene for Underground Drainage of Rain Water UNI 11434 (Italy) Steel Reinforced Spirally Formed Polyethylene Pipes for None Pressure Underground Drainage and Sewerage CSA...