Geothermal Pipe Types Available
The most commonly available pipes for plumbing are:
PVC and CPVC
PVC has been used for many years in residential construction. Even though it can carry some pressure ratings it is not suitable for high pressure applications. It comes widely available in different diameters and lengths.
It has some resistance to chemicals. PVC is easy to assemble in different configurations but is not really suitable for a closed loop application as it has been proven to fail in keeping the loop sealed and it doesn’t bend easily. A Leak underground after your geothermal installation has been completed can be a serious headache.
CVPC is a low cost piping option that has a weak chemical resistance and will degrade in contact with corrosive agents. It works well for pressurized water flow. and it is commonly used for portable water applications. Like the PVC piping, it can’t be sealed by fusion and instead needs adhesives to seal. It is not an ideal method for geothermal applications as underground leaks can also occur.
The most used piping materials in the geothermal industry are:
Polyethylene Pipe (PE) and High Density Polythylene Pipe (HDPE)
(PE) This pipe is made out of a though, light and flexible resin made by polymerizing ethylene. Most geothermal contractors use this product for being available in shapes like “Slinky” , has a good chemical resistance and can be sealed by heat fusion which minimizes the risk of an installation leak. It is ideal for horizontal pipes or slinky configurations. Even though it’s more expensive material than PVC and CPVC because of it’s durability and strength advantages, it still lacks pressure ratings needed for geothermal vertical installations.
(HDPE) This is the most effective pipe material available for geothermal installations. It is a higher quality than (PE). It offers better material strength, thermal properties, pressure ratings and resistance to chemical corrosion. The manufacturer warranty available for this product is higher than any other type of pipe. Sometimes exceeding 50 years. It is excellent for vertical installations and large pressure ratings and like the (PE) it offers a great seal through heat fusion.