High-density polyethylene (HDPE) pipe is a good choice for underground water lines because of how the pipe is connected. Rather than using joints, which can leak, or glues and cement, which can degrade over time, HDPE pipe is connected via plastic fusion.
HDPE pipe is the best, second is PVC sch. 40 or 80. I would never use the cheaper 100- 160 psi black poly pipe in rocks, or where you have gophers. The key to black poly pipe is to leave it with a lot of slack in the trench,do not pull it tight. When the ground frost heaves it will pull out of the fittings.
Comparison between PEX pipes and PVC pipes for water supply systems. 1. Durability: Both PEX pipes and PVC pipes are known for their durability and long-lasting nature. However, PEX pipes tend to have better resistance to extreme temperatures and thermal expansion/contraction, making them less prone to leaks or bursts.
Pex is the better material. Rodents can chew holes in either but more easily with pex. Neither has good uv resistance and pex can absolutely not be in direct sunlight. Pvc is cheaper but pex is the easiest thing to work with. But if rodents are an issue then copper is really the way to go.
Cast iron will last anywhere from 75-100 years while PVC wins the award for longest-lasting pipe material with an indefinite lifespan.
HDPE offers flexibility because it can withstand strong impacts. Be it the weather condition or the force of water, these pipes serve uniformly during every situation. So, when you install these pipes for underground water supply, you can trust the quality. Moreover, these pipes remain unaffected due to motion fatigue.
Cast Iron
Despite the heat resistance and noise-dampening properties of cast iron, it's not as suitable for underground water supply as newer materials. Cast iron is not resistant to corrosion, which can compromise the quality of the water supply and damage the integrity of the piping, leading to leaks and breaks.
PEX: Due to its flexibility and durability, PEX piping should last at least 50 years. PVC / CPVC: Under typical conditions, these pipes should last up to 100 years. Keep in mind that PVC pipes are often used for drainage because extreme heat can damage them.
Cost Comparison
Galvanized steel pipes tend to be the most expensive option and can be costly to install and repair. Copper can be a costly material, but it may still be a good choice if you value durability and reliability.
PEX piping has a maximum bend radius, which can lead to stress on the pipe caused by improper installation. In addition, extreme bends and kinks place a very high local stress on the wall of the pipe, making it more susceptible to oxidative degradation.
Material Concerns: One of the primary concerns about Pex plumbing is the material itself. While Pex pipes are undoubtedly flexible, making them easier to install in tight spaces, they are not as durable as traditional materials like copper or even PVC.
PVC is most commonly used for drain, waste, and vent lines. It is not recommended for use in potable water lines because it can leach chemicals into the water.
Yes, PEX pipes can be buried underground. However, it's important to follow local building codes and guidelines to ensure compliance and the longevity of your plumbing system. To ensure optimal performance and protection against external factors, it is essential to bury insulated PEX pipe at the appropriate depth.
This means that you would typically want your water lines to be at least 4.5 feet below the ground level or possibly even deeper if you live in the mountains or the foothills. The sewer lateral leading from your house out to the municipal sewer main should also be at the same depth as it could also freeze.
The Lifespan of a Water Line
The mainline provides homes, particularly within a suburban or urban housing development, with running water. Typically, main water line pipes last decades. Some experts estimate that they last around 70 years, though this can vary from development to development.
International Plumbing Code states exterior water supply system piping should ideally lie 6 inches below the frost line and not less than 12 inches under grade for best performance.
Metal pipes are quite resistant to impact damage and corrosion, an excellent choice for a heavy-duty underground water line. A copper pipe has the highest level of resistance to corrosion.
PVC is the cheapest option, but it's not necessarily the best pipe for every application. For example, using PVC pipes for drinking water or hot water is not recommended. The next in line is ABS piping, with PEX piping being the most expensive.
Cost per Foot
Installing a water main costs an average of $50 to $150 per linear foot. Prices may reach as high as $250 per linear foot in areas with high cost of living and for lines that are difficult to access.
Copper is usually preferred for water supply lines and heating systems but plex is most often used for drain or waste lines because copper corrodes over time. Ultimately, it's up to the homeowner to decide where to spend the construction budget.
If using a PEX pipe underground, bury it at least 12 to 18 inches below the frost line. The temperature is warmer just a few feet below the surface. In a cold region, the frost line may be three or feet down, so this is an important consideration.
Asides for its versatility, the cinch tool is also cheaper than the crimp tool. The cinch rings can be slightly more expensive than crimp rings. A cinch connection will last over 5 years and can last more than 10 years. Crimp connections consist or a crimp ring, a crimp tool, proper fittings and a go/no-go gauge.
PVC can last even longer than steel or copper, which are some of the most durable metals for plumbing pipes. Ability to handle pressure: PVC can withstand high water pressure, which makes it an excellent choice for the main supply line in your home.
PEX A offers higher burst resistance, capable of withstanding up to 500 PSI in extreme cold, while PEX B, being more rigid, is less resilient.
PVC pipes have varying wall thicknesses. In pipe-speak, this wall thickness is known as schedule. PVC pipe schedules can range from 10 to 160 but schedules 40, 80, and 120 are the most commonly used for underground applications.