110 E Crowther Ave. Placentia, California, 92870

Endurance of PVC Pipes: A Comprehensive Study8OCT

Understanding the longevity of PVC pipes improves a water utility’s capacity for making sound

infrastructure investment decisions with more affordable prices for customers. A recent study looked

at the combination of pipe examination and testing date, previous pipe break studies and dig-up

reports of in-service pipes. The study is based on new quality test results and life-cycle cost analysis.

These findings support that PVC exhibits performance and longevity that exceeds 100 years, which is

twice as long as some pipe professionals would admit. As we don’t know for sure how long in service

PVC pipe will last, 100 years may even be a conservative estimate. At a minimum, the 100 year

benchmark can be used as the new industry standard. These findings are a follow up to a 2012 study

that illustrated that PVC has a lower water main break rate than cast iron, ductile iron, steel, asbestos

cement, and concrete.

PVC Pipes remain unaffected despite long usage

PVC has no natural enemies that degrade or attack it, and it is not susceptible to corrosion or

oxidation like many alternative pipe materials. As long as the fluid is being transported in flowing

freely, pipe performance is not affected by low temperature. Stabilizers are used in PVC pipes to

prevent polymer degradation during the extrusion process and pipes storage before they are placed

in the ground. Once the pipes are in the ground, there should not be any chemical degradation taking

place, which is a primary factor in PVC pipe longevity.

110 E Crowther Ave. Placentia, California, 92870

Some of the PVC pipes that were excavated for recent studies were nearly 50 years old and met

applicable standards. Around the world, the studies confirmed that PVC pipes show no degradation

after decades of operation. There is virtually no change in mechanical properties as a result of aging

with both resistance and ductility to internal pressure at the same level as new pipes.

Corrosion free

One of the major findings from the study is that including PVC piping that is corrosion proof in water

utility replacement programs and procurement strategies can decrease water main breaks,

operations, and maintenance costs. Iron piping corrosion is a major issue for water systems. The

average water main fails at 47 years due to corrosion. Newer metallic pipes have thinner walls, which

make them fail more quickly than older designs. PVC piping solves this issue. Heightened

installation and inspection practices also play a role in reduced failure rates and increased pipe

affordability and longevity.

When PVC pipes do fail within a short period of time, it is almost always due to one of two causes.

o The first cause is a defective pipe, typically brought about by PVC incomplete gelation. Manufacturer

quality control tests on each pipe lot should prevent this problem.

o The second cause is improper installation procedures, which is more often the issue than defective

pipes.

Whether you are using PVC or another kind of pipe, you should always adhere to proper quality

control and installation protocol. Other common causes of failure include choosing the wrong

material and using it in a poorly designed or maintained system.

Market demand of PVC Pipes in the U.S

Currently PVC pipe makes up approximately one third of the water infrastructure in the United

States. This figure is only expected to grow over the coming decade. There is no single pipe that is the

answer for all pipe expansion and replacement. It’s like saying who makes the best car? This doesn’t

change the fact that PVC is a high quality, versatile product that can exceed 100 years when it is

installed properly.

Over one million miles of pipe are nearing the end of their useful life in the United States alone. The

combined cost of replacing the pipe and expanding portions of the water system is over $1 trillion.

When you run the numbers to determine the best investment for pipe replacement and expansion,

you must consider how long the pipe will last. Ideally you should be able to use the base of 100 years

for PVC pipe.

There are a number of factors that go into purchasing pipes including weather, soil, and corrosion

conditions; geography; and whether or not transmission or distribution lines are being replaced. As

such, every company must take the time to crunch the numbers. The goal is to find the pipe with the

lowest cost and longest life span with an infrastructure building budget that doesn’t break the bank.