Reinforced Thermoplastic Pipe (RTP) combines high performing materials with high strength reinforcements in a unique construction to create a spoolable high pressure pipeline system. This construction is well suited to a variety of applications. The primary use of RTP has been in the upstream oil and gas industry for a range of applications covering oil gathering, gas gathering, water injection and water disposal. RTP has also been installed in eleven gas distribution applications in Canada.
Steel pipe used to be an ideal choice for gas pipelines based on its cost, usability and strength. However, there is also a series of limitations in steel pipe. The first is corrosion resistance, followed by the monitoring and environmental issues.
The installation cost of steel pipes is very high, due to the weight and length limitation. Additional cost will be added for labor and equipment in the pipe processing, carrying, connecting and testing. At present, many other materials can be used to replace steel pipes. Polyethylene and aramid are successful in some applications, but limited by their compressive capacity. The rigid glass fiber reinforced thermosetting resin has also been used for many years in various fields. However, the problems faced by such composite pipes have always been the reliability of the connection and the susceptibility to external loads.
Glass fiber reinforced thermoplastic pipe is another material to replace traditional pipes. it overcomes the inherent shortcomings of non-reinforced plastic pipes and thermo-set composite pipes. due to the unique features of cost-saving, corrosion resistance, high compressive capacity, ruggedness and convenient installation, this technology is very attractive to users, including gas distribution pipeline operators.
RTP Pipe Structure
The RTP pipe is usually a 3 layer structure: a thermoplastic liner for material transport, a high strength glass fiber reinforcement layer providing strength, and a thermoplastic cover protecting the pipe wall. Such a structure contains no thermosetting resin, achieving a perfect combination of high strength, corrosion resistance, flexibility and durability. The flexible RTP pipe can be coiled up, convenient for transportation and installation.
RTP Pipe Connecting
The RTP pipe is connected through metal flange clamping. The connecting can be achieved by using portable pipe crimping devices without heating or bonding. The pipe ends can be processed by standard loop-over lap flanges or welded conversion necks. Field welding procedures are allowed in the connecting.
RTP Pipe Laying
Simple laying is one of the biggest advantages of RTP pipes compared to other high pressure pipes. Being able to be coiled, reinforced thermoplastic pipe can have a longer length and a durable outer jacket. These factors make installation easier and faster, and cost saved.
This is a successful case of RTP pipe used in gas distribution by AltaGas Utilities Inc. With the continuous increase of experience in RTP pipe application, its great significance in the field of natural gas distribution and transportation is gradually being recognized. Reinforced thermoplastic pipes will undoubtedly continue to improve as an integral part of the natural gas distribution process.