Benefits of Plastic
for Casing and Screen
Until PVC entered the picture, there weren’t many options. Because of its light weight and durability, it can be money in the bank for most installations by saving time and reducing labor, transportation and maintenance costs. PVC’s lighter weight makes it easier and less costly to handle, transport and install. PVC will not rust, pit, scale or corrode, giving it an extremely long lifespan. Aggressive soils, biological attack and other residue buildups are virtually non-existent. PVC is non-toxic and imports no taste into the water.
To complement the use of PVC in new well construction, it is commonly used as a liner in old wells. This is a viable alternative over the drilling of a new well. PVC-threaded well casing and liner is available in nominal sizes from 4 inches to 10 inches. The more common sizes for residential use are 4.94 inches and 6 inches (outside diameter). These sizes are preferred over the standard sizes available in typical schedule 40 pipe. Using plastic pipe and fittings available only from within the industry helps ensure any changes to the well construction during and after completion is only handled by a qualified person. Most suppliers distribute their products to licensed contractors only, making it difficult for the unlicensed and untrained to obtain this product. This in itself goes a long way to ensuring that the installation and maintenance is handled professionally.
Decades of development have resulted in specific thread types, pipe slotting and specialty fittings. Flush threading is preferred as a way to achieve a straight, smooth internal and external casing wall, while maintaining a watertight seal. When using PVC as a slotted well screen, it can be installed in the middle of the pipe string maintaining the flush casing wall, thus dramatically reducing the possibility of pump hang-up. A wide range of casing fittings are available, including packers, couplings and stainless screen adapters.
PVC has grown in use over the years to become the casing and liner of choice in most areas. Something as simple as plastic is able to contribute to safe drinking water.