Whether you are a pipe manufacturer, construction professional or a curious consumer looking for the best piping for a small home project you may be wondering what the main differences and applications are between PE and PVC pipe.
PE vs PVC Pipe: What they Have in Common
PVC and PE pipe are both comprised of thermoplastic materials; Polyvinyl chloride (PVC) and polyethylene (PE). Both of these materials can be used for pipe extrusion with excellent results over traditional pipe materials such as concrete and steel.
Both PE and PVC pipes are commonly used to transport large volumes of liquid (water, fertilizer, hazardous chemicals) at a high velocity. Plastic pipe are able to maintain this velocity with less drag and turbulence than traditional concrete or metal pipes providing greater resistance to scaling and buildup. PE and PVC pipes are also better at maintain a uniform temperature across the pipeline system and are resistant to a number of chemicals, severe environmental factors, and aggressive fungi in soils. Both PE and PVC pipes can be used over long periods of time and serve as a cost effective piping solution for any application.
So, with all of the similarities between PE and PVC what truly differentiates the two pipe types?
Uses of PVC Pipes
PVC is a light-weight, inexpensive, rigid thermoplastic that requires a twin screw pipe extruder because of the harshness of the material in its raw state. Pipes made of PVC are less sensitive to thermal expansion (elongation) than PE pipe. So, a PVC pipe system exposed to fluctuating external or internal temperatures is better protected from possible damage caused by pipes shrinking and expanding. Heat distortion of PVC begins to occur at temperatures over 60°C (140°F) and excessive exposure to cold can cause the pipe become brittle when frozen. So, PVC is not suitable for applications like kitchen drains or installations exposed to harsh weather.
In fact, some types of PVC are not suitable for drinking water due to their chemical compositions, while other types are approved for potable water use. Common applications include sewers, water mains, drain/waste/vent, and irrigation. Because PVC is sensitive to UV light, if it is used above ground, it should contain stabilizers and UV inhibitors and may require painting with a water-based latex paint.
Due to its rigidity PVC pipe cannot be coiled and has to be transported in rigid segments. This rigidity limits the total linear feet of pipe that can be stored and transported at one time, increasing transportation costs. PVC pipe requires fittings at each rigid section, making installation labor-intensive and increases the risk of leaks and joint failures at each connection point.
Because PVC is stiff, it can make installation on uneven ground difficult, requiring ground to be leveled to produce satisfactory results. If a grade is required, PVC will maintain grade well once installed. However, due to its rigidity, unlike flexible PE pipe, PVC only requires intermittent supports when hung.
Uses of PE Pipe
PE pipe is flexible and is manufactured as one continuous piece of pipe that can be cut to length. Because it is flexible and lightweight (compared to traditional materials like concrete and steel), PE pipe can be stored and transported in coils, or cut into sections. Uneven ground is also less of a concern, as flexible PE pipe easily accommodates hills, valleys, and obstacles.
Rather than frequent connections, PE can be fused together, creating a continuous, virtually leak-free system, producing a more efficient and economical installation. While fusing does require special tools, fewer connectors and fittings reduces water-velocity-drop and friction which can cause pressure loss over the system.This means less energy is used to run pumps.
Its flexibility allows for smaller entry pits which helps reduce the inconveniences for the surrounding local community during installation and maintenance. These characteristics make PE ideal for trenchless installation methods as well.
PE also demonstrates excellent resistance to slow crack growth (SCG) and rapid crack propagation (RCP) and maintains these properties over a wide range of temperatures, including very low temperatures. Technical property advantages include leak, crack, burst, tear, puncture, and chemical resistance, making PE suited to an extensive range of applications.
PE possesses excellent toughness, durability, and longevity, with studies showing a life expectancy of over 100 years. So, handling is easy, and systems can expect a long performance life.
PVC pipe is ideal as a low-cost material option for pressurized and/or suspended systems that are free from extreme temperature fluctuations. But, for projects involving drinking water, exposure to extreme temperatures, or where ungraded or above-ground installation is required, PE pipe is the right choice.
3-Layer Pipe Technology
Both PVC and PE are appropriate choices for manufacturers who want to take advantage of the cost savings, versatility and environmentally friendly benefits of 3-layer pipe technology. 3-layer pipes are manufactured using a special 3-layer die head which extrudes an inner and outer layer separated by a core of different material. Three layer pipes can meet the technical standards of a high-quality polymer single layer pipe with less cost by using an inexpensive core material, generally regrind. Three-layer pipe also provides greater versatility by allowing selection of layer materials to meet environmental and fluid handling challenges.
PE & VC Pipe Extrusion Machines
If you are setting up a new production line or renovating a current line for PVC or PE pipe manufacturing, the team at DRTS can help you choose the best options for your market and your company. Get a free expert consultation to learn more about our pipe manufacturing solutions