Non-metallic Pipe

Non-metallic pipes are pipes that are not made of metal materials.  Instead, they are composed of various non-metallic materials, such as polymers, plastics, ceramics, and composite materials.  These pipes are commonly used for conveying fluids and gases in various industrial, commercial, and residential applications.  Non-metallic pipes offer several advantages, including corrosion resistance, lightweight design, ease of installation, and the ability to withstand certain chemicals.

Common Types of Non-metallic Pipes

Polyvinyl Chloride (PVC) Pipes  -  PVC pipes are widely used for water supply, drainage systems, and irrigation.  They are lightweight, durable, and resistant to corrosion.
Polyethylene (PE) Pipes  -  PE pipes are commonly used for gas and water distribution.  They are flexible, resistant to chemicals, and have good impact strength.
Fiberglass Reinforced Plastic (FRP) Pipes  -  FRP pipes are made of a composite material consisting of fiberglass and resin.  They are corrosion-resistant and often used in chemical processing plants.
Polypropylene (PP) Pipes  -  PP pipes are used for a variety of applications, including chemical processing, wastewater treatment, and industrial piping systems.
Acrylonitrile Butadiene Styrene (ABS) Pipes  -  ABS pipes are known for their toughness and impact resistance.  They are commonly used for drain, waste, and vent (DWV) systems in residential plumbing.
High-Density Polyethylene (HDPE) Pipes  -  HDPE pipes are known for their high strength, durability, and resistance to chemicals.  They are used in various applications, including water and gas distribution.

Non-metallic pipes are chosen based on the specific requirements of the application, considering factors such as the type of fluid or gas being conveyed, environmental conditions, and the overall system design.  While metallic pipes are still widely used in many industries, non-metallic pipes offer valuable alternatives in situations where their unique properties are advantageous.

 

Non-metallic Pipe Advantages and Disadvantages
Advantages	Disadvantages
Non-metallic pipes are often corrosion resistant, making them suitable for transporting corrosive fluids without the risk of degradation over time. Non-metallic pipes are generally lighter than their metallic counterparts, making them easier to handle, transport, and install.  This can contribute to labor and cost savings. Flow properties are superior to steel pipe, lower pumping costs, and consistent friction factor through the life of the pipe. Non-metallic materials have inherent insulation properties. Non-metallic pipes may provide better insulation against heat or cold compared to metal pipes. Many non-metallic materials exhibit excellent resistance to various chemicals, making them suitable for applications where exposure to aggressive substances is a concern. Will not corrode if the correct material is selected.  No cathodic protection or corrosion monitoring.  No chemical inhibitors are required.  Corrosion allowance is avoided (Note: if the service is an erosive service, an erosion allowance may be required). Non-metallic pipes often have a smooth interior surface, promoting good fluid flow with reduced friction and the potential for clogs. Non-metallic pipes are non-conductive, making them suitable for applications where electrical conductivity is a concern or where insulation from electrical currents is required. Depending on the specific material, non-metallic pipes can be cost effective, especially in applications where corrosion resistance and weight are critical factors. Non-metallic pipes are available in various materials, including PVC, CPVC, HDPE, fiberglass, and more, allowing for selection based on specific application requirements. More flexible than steel pipe.  This allows for some nonmetallic piping to be ordered in spools that are hundreds of feet long.	Some non-metallic materials may have temperature limitations, and their performance could be compromised at extreme temperatures. Temperature limits are usually lower than steel pipe.  As temperatures increase, the maximum pressure will decrease. Maximum pressure is lower than steel pipe. Certain non-metallic materials, like certain plastics, may be sensitive to ultraviolet (UV) light, potentially leading to degradation over time when exposed to sunlight. Material is very process dependent.  That is, hydrocarbons cannot always flow through nonmetallic lines. Non-metallic pipes may have lower mechanical strength compared to some metals, limiting their use in high pressure or high stress applications. Non-metallic lines will degrade in sunlight without a ultraviolet inhibitor. Very susceptible to mechanical damage. Some non-metallic materials may be more permeable than metals, potentially allowing the passage of gases or liquids through the pipe wall in certain situations. While some non-metallic materials are fire resistant, others may pose fire hazards, and their performance in the event of a fire can vary. More flexible than steel pipe.  Requires more supporting than steel piping. Certain non-metallic materials may not be suitable for high temperature applications where metal pipes, such as steel or stainless steel, are preferred. Joining non-metallic pipes may require specific methods, such as gluing, welding, or using specialized fittings, which can be different from traditional metallic pipe joining methods. Compatibility with specific chemicals or fluids needs to be carefully considered, as not all non metallic materials are suitable for all substances.

 

Common Uses of Non-metallic Pipe

Non-metallic pipes are used for a variety of applications across different industries due to their specific characteristics and advantages.  The choice of non-metallic pipes depends on the specific requirements of each application, considering factors such as the type of fluid or gas being conveyed, environmental conditions, and the overall system design.  The advantages of non-metallic pipes, such as corrosion resistance, lightweight design, and ease of installation, make them suitable for a wide range of purposes.

Water Supply and Distribution  -  Non-metallic pipes, such as PVC (Polyvinyl Chloride) and HDPE (High-Density Polyethylene), are commonly used for water supply and distribution systems in residential, commercial, and industrial settings.  These pipes are corrosion resistant and provide a durable solution for conveying potable water.
Chemical Processing  -  Non-metallic pipes like FRP (Fib
erglass Reinforced Plastic) and PP (Polypropylene) are often used in chemical processing plants where resistance to corrosive chemicals is crucial.  These pipes can handle a wide range of corrosive substances without degradation.
Wastewater and Sewage Systems  -  PVC and HDPE pipes are frequently used in sewage and wastewater systems.  Their resistance to corrosion and chemicals makes them suitable for conveying wastewater without the risk of degradation.
Irrigation Systems  -  PVC and polyethylene pipes are commonly used in agricultural applications for irrigation systems.  Their lightweight design, durability, and resistance to environmental conditions make them well-suited for this purpose.
Gas Distribution  -  Polyethylene pipes are widely used for the distribution of natural gas.  These pipes are flexible, resistant to corrosion, and have good integrity, making them a reliable choice for gas transmission.
Mining and Slurry Transport  -  Non-metallic pipes like HDPE and lined pipes are used in mining operations for transporting slurry and abrasive materials.  The abrasion resistance of these pipes makes them suitable for handling challenging materials.
Electrical Conduit Systems  -  Non-metallic conduits, often made of PVC, are used to protect and route electrical wiring in residential, commercial, and industrial buildings.  They provide insulation and protection against environmental factors.
HVAC Systems  -  PVC pipes are used HVAC systems for the distribution of chilled water and other fluids.  They are corrosion resistant and can handle a range of temperatures.
Telecommunications  -  Non-metallic conduits are also used in the telecommunications industry to protect and route fiber optic cables and other communication lines.
Plumbing Systems  -  Various non-metallic pipes, including PVC and ABS (Acrylonitrile Butadiene Styrene), are commonly used in plumbing systems for drain, waste, and vent (DWV) applications in residential and commercial buildings.

Non-metallic Pipe Standard 

ASME Standards  -  Not all non-metallic piping can be used in all services. For example:

• ASME B31.3 - Process Piping
  • • Thermoplastics cannot be used when the service is a flammable service and when the piping is above ground.  Thermoplastics also must be safeguarded when in all services (except in Category D fluids).  While safeguarding is not defined, it could mean that additional pressure & temperature protection is required.  It could also mean that physical barriers be installed to prevent unintentional rupture.
    • Thermosets can be installed if they are safeguarded when the service is flammable or toxic.
• ASME B31.4 - Pipeline Transportation Systems for Liquid Hydrocarbons and Other Liquids does not allow thermoplastics.
• ASME B31.8 - Gas Transmission and Distribution Piping Systems allows for nonmetallic piping at low pressures (<100psi)