Plastic water pipes are also included in the pervasively used piping solutions because they are reliable, rigid, flexible, and corrosion-resistant. In contrast to galvanized pipes, plastic pipes contain synthetic materials such as polyvinyl chloride, chlorinated polyvinyl chloride, and cross-linked polyethylene.
Other benefits of the materials include low cost, ease of installation, and reduced risk of leak because they are seamless with fewer joints. PVC and CPVC pipes are used for cold and hot water distribution.
5 Types of Plastic Water Pipes:
1. PEX Pipe
PEX stands for cross-linked polyethylene pipe. It is a form of plastic tubing used in plumbing or heating systems because it is strong, flexible, resistant to high temperatures, and long-lasting. The manufacturing process involves the chemical or physical cross-linking of polyethylene molecules. Cross-linking ensures the material has better mechanical strength with high thermal stability. Such processes can resist high pressures and temperatures, so they should work with hot and cold water distribution systems.
Since PEX piping is very flexible, it can be manipulated as needed to go around corners and past obstacles without using multiple fittings and joints. This characteristic reduces potential leakage points and allows quicker, more cost-effective installations. PEX is resilient to scale and chlorine, which further protects the quality of the water and gives the plumbing system a longer life expectancy.
Applications of PEX Pipe
Water supply lines:
PEX pipelines supply hot and cold water in many residential buildings. Due to their increased flexibility, they are relatively simpler to install than rigid piping materials.
Radiant floor space heating:
Although PEX tubing can withstand relatively high temperatures, its flexibility facilitates its installation in diverse patterns. Consequently, it is employed in radiant floor heating.
Hydronic heating systems:
In hydronic heating systems, which employ PEX pipelines, water or a combination of water and glycol is the medium for heat transfer.
Compressed air systems:
Because of its ability to withstand pressure and stress, PEX pipelines are suitable for compressed air systems.
Read our post on Copper Vs. Pex Pipe: How To Choose
PEX Pipe Sizes:
PEX is primarily used in 1/2″ or larger. It can be installed with crimp fittings or quick-connect fittings.
Inner Diameter (ID) | Outside Diameter (OD) | Bend Radius |
1/8″ | 1/4″ | 1-1/2″ |
1/4″ | 3/8″ | 3″ |
3/8″ | 1/2″ | 4″ |
1/2″ | 5/8″ | 5″ |
3/4″ | 7/8″ | 7″ |
1″ | 1-1/8″ | 10″ |
2. ABS Pipe
Acrylonitrile Butadiene Styrene, or ABS, is a plastic water conduit widely used in residential piping systems. Compared to other plastic water pipes, ABS water pipes are softer and have a black color. Vent and discharge lines are the primary applications for Acrylonitrile Butadiene Styrene. It is primarily employed for outdoor activities in regions with prevalent frigid temperatures.
ABS is the safest choice for residential use due to its non-toxic nature and approval for potable water lines. Additionally, it is highly rigid and resistant to abrasion plastic pipe. Unlike other plastic water pipelines, ABS is not as effectively affected by direct sunlight. Your plumber should apply a UV-resistant chemical to the pipe to safeguard it if it is required to be used in direct sunlight.
Applications:
Drain-waste-vent (DWV) systems: ABS pipes are primarily used in drain-waste-vent (DWV) systems in residential, commercial, and industrial buildings. Due to their rigid and lightweight nature, they effectively manage the flow of wastewater and gases in venting.
Sewer systems: ABS pipes are suitable for sewer systems across the board since they usually perform well against chemical corrosion and abrasion. They can move waste materials week in and week out without degrading.
Ventilation Systems: ABS pipes are used in ventilation systems, vent exhaust and air handlers.
Waste disposal systems: The ABS pipes find applications in systems for discharging solid and liquid wastes; they work efficiently with waste materials from commercial kitchens to food processing plants.
Size of ABS Pipe:
Nominal Pipe Size (inches) | Outside Diameter (OD) (inches) | Schedule (Wall Thickness) |
1 ¼ | 1.660 | Schedule 40 |
1 ½ | 1.900 | Schedule 40 |
2 | 2.375 | Schedule 40 |
3 | 3.500 | Schedule 40 |
4 | 4.500 | Schedule 40 |
6 | 6.625 | Schedule 40 |
8 | 8.625 | Schedule 40 |
10 | 10.750 | Schedule 40 |
12 | 12.750 | Schedule 40 |
3. PVC Pipe
Made from vinyl and plastic, these pipes have high strength per unit weight, making them strong with less weight. They are resistant to corrosion, chemical damage, and abrasion and thus durable and reliable for transferring water and other fluids.
Due to their chemical resistance, PVC pipes can carry acids, alkalis, and industrial chemicals. They are also resistant to all kinds of biological degradation by bacteria or fungi; thus, they stand out as suitable for all applications where exposure has to be made over a long period in many environments. In this regard, PVC pipes are useful in above-ground and underground installations, proving their versatility in plumbing work.
Applications:
PVC may have the most extensive plumbing applications among plastic pipelines used for water supply.
Although it is employed as a water main or drainage conduit, it has also been used for irrigation piping. You may also locate some in-water systems integrated into baths and swimming pools.
Any application that involves temperatures exceeding 140 degrees Fahrenheit and hot water distribution are among the few exceptions.
Standard Size:
Nominal Pipe Size (inches) | Outside Diameter (OD) (inches) | Schedule 40 Wall Thickness (inches) | Schedule 80 Wall Thickness (inches) |
½ | 0.840 | 0.109 | 0.147 |
¾ | 1.050 | 0.113 | 0.154 |
1 | 1.315 | 0.133 | 0.179 |
1 ¼ | 1.660 | 0.140 | 0.191 |
1 ½ | 1.900 | 0.145 | 0.200 |
2 | 2.375 | 0.154 | 0.218 |
2 ½ | 2.875 | 0.203 | 0.276 |
3 | 3.500 | 0.216 | 0.300 |
4 | 4.500 | 0.237 | 0.337 |
4. CPVC
CPVC pipe stands for Chlorinated Polyvinyl Chloride and is a thermoplastic pipe made from CPVC resin. The process enhances the material’s temperature and chemical resistance properties over the standard PVC pipes. CPVC pipes have excellent mechanical strength, high heat, and corrosion resistance.
They are more temperature-resistant than PVC pipes, usually reaching 200°F for continuous operation and 210°F intermittently.
CPVC pipes have resistivity toward a significant number of corrosive chemicals, including acids, alkalis, and salts. The ability of this characteristic gives them the outreach to be used in industrial piping, particularly in most chemical processes and laboratory applications where equipment is exposed to high doses of chemicals.
Applications:
Hot and cold water distribution: CPVC pipes are widely used in hot and cold water distribution systems in residential, commercial, and industrial buildings.
CPVC can withstand temperatures up to 200F or 93C without degrading, so it will be appropriate in high-temperature, high-strength applications where PVC is not strong enough.
HVAC systems: CPVC pipes are highly demanded in heating, ventilation, and air-conditioning systems to carry hot and cold water and refrigerant lines.
Their capacity to bear thermal expansion and ensuing contraction, along with other properties, provides an unrivaled service life and makes them ideal in such contexts.
Residential plumbing: CPVC pipes are used for residential plumbing of all types, but especially in areas where the building codes require higher temperature ratings or where concerns are raised about water quality and corrosive resistance.
Size:
Nominal Pipe Size (inches) | Outside Diameter (OD) (inches) | Minimum Wall (Inches) |
¼ | 0.540 | 0.119 |
3/8 | 0.675 | 0.126 |
½ | 0.840 | 0.147 |
¾ | 1.050 | 0.154 |
1 | 1.315 | 0.179 |
1 ¼ | 1.660 | 0.200 |
2 | 2.375 | 0.218 |
2 ½ | 2.875 | 0.276 |
3 | 3.500 | 0.300 |
5. HDPE
A plastic water conduit, “high-density polyethylene,” is employed for all plumbing requirements. It is the preferred choice of many due to its durability and strength. HDPE’s low coefficient of friction can reduce water pressure, enabling water to circulate readily within. It is eco-friendly and corrosion-resistant.
HDPE pipelines are attached using heat-fusion welding and are always free of discharge. Due to their corrosion resistance, they are safe to use in water lines in residential and commercial plumbing systems. In addition to water lines, HDPE is employed in wastewater, chemicals, and compressed gases.
Standard HDPE Pipe Sizes and Their Applications
Small diameter pipes (20mm to 32mm):
These smaller sizes are employed to protect fiber optic cables, as service lines for residential water supply, and as micro-irrigation systems. They are also widely used in landscape irrigation and for distributing potable water to individual sites.
Pipes with a medium diameter (50mm to 110mm):
Larger irrigation systems, municipal water supply, sewerage, and drainage systems are ideal applications for medium-range HDPE pipelines. They are extensively utilized in urban and rural potable water supply lines and as primary conduits in community drainage.
Pipes with a diameter above 110mm:
Larger diameter pipelines are employed in high-demand applications, such as municipal water mains, industrial effluent conduits, hot water drainage systems, and firewater. They are also used as conduits for larger cables and channel lines for effluent treatment facilities.
Conclusion
Plastic water pipes come in different types for use and size, thus serving as the mainstay in today’s plumbing and construction. Each material benefits from the five major categories of plastic water pipes—PVC, CPVC, PEX, HDPE, and ABS.
PVC and CPVC being used because of their strength and resistance to corrosion, and PEX is preferred for its flexibility and malleability, which make it easier to install.
Knowing each type’s distinct features and appropriate applications assures effectiveness and reliability in a water distribution system in commercial, residential, or industrial settings.