“If I’d known I was going to live so long, I would have taken better care of myself.” — Billy Noonan
The 1967 film, The Graduate, has one of the most famous lines in all of cinema. Mr. McGuire is giving advice to recent college graduate, Benjamin Braddock, played by Dustin Hoffman.
Mr. McGuire: “Just one word. Are you listening?
Benjamin: “Yes, I am.”
Mr. McGuire: “Plastics.”
With that one word, that endorsement from popular culture, the chemical industry approached its zenith. Sure, production has continued to grow, but as for the view from popular culture, it’s been either no news or bad news ever since.
The chemical industry is getting old and it’s showing.
An Aging Industry
The oldest petroleum refinery still in operation is the Point Breeze refinery in Philadelphia, built in 1866 by Atlantic Refining, which was purchased by Standard Oil in 1874. Standard Oil built the Whiting Refinery in Indiana, just east of Chicago, in 1889, and the Richmond Refinery in California, just northwest of San Francisco, in 1902. The average age of the 131 refineries operating in the United States (as of March 6, 2026) is over 50 years.
Because of the diversity of the chemical enterprise, it’s hard to say what the oldest operating chemical plant in the United States is. E.I. du Pont built a gunpowder mill on the Brandywine River, near Wilmington, Delaware. Du Pont closed the mill in 1921, but the DuPont Experimental Station still operates across the Brandywine from the original site.
Entrepreneurs constructed many plants in the decades after that, but it wasn’t until after World War II, in the 1940s, that construction of new chemical plants really took off. By 1970, the year that Congress created the U.S. Environmental Protection Agency, the boom was over. New chemical enterprises start up, and new plants continue to be built, but not as frequently. According to the U.S.EPA there are about 13,500 chemical manufacturing facilities in the United States, owned by about 9,000 different companies, meaning that most chemical plants companies own just one plant. In a recent post by IndustrySelect, they reported that the average company age in the chemical industry is 46 years.
As the chemical industry ages, so does the process equipment used in chemical facilities.
Aging Equipment
While plants may last forever (or at least centuries), equipment does not. Three common types of equipment in the chemical process industries are piping systems, storage tanks, and centrifugal pumps. They all have a recognized useful life:
For piping systems, different materials of construction have different useful lifespans. Assuming that the material of construction is initially suitable for the material it is transferring – a piping system carrying a solvent that will dissolve it has no useful lifespan to speak of – it can range. These useful lifespans are commonly reported:
- Brass: 40 to 70 years
- Copper: 50 to 70 years
- Cast iron: 50 to 100 years
- Galvanized steel: 20 to 50 years
- PVC (polyvinyl chloride): 25 to 40 years
- CPVC (chlorinated polyvinyl chloride): 50 to 75 years
- HDPE (high density polyethylene): 50 to 100 years
- PEX (crosslinked polyethylene): 40 to 50 years
The useful life of a storage tank is also highly dependent on the material of construction, again assuming that the material of construction is suitable for the substance being stored in the first place. Here are some reported values:
- FRP (fiberglass reinforced plastic): 20 to 30 years
- Polyethylene: 10 to 15 years
- Polypropylene: 10 to 20 years
- Carbon steel: 10 to 20 years
- Stainless steel: 15 to 30 years
As an equipment category, pumps have the shortest useful life of the three types discussed here. A key difference between pumps and tanks and pipes is that pumps have moving parts, which changes the wear. Jim Elsey tells us that “a standard L-frame American National Standards Institute (ANSI) pump can be expected to operate for 15 to 20 years…” Then he adds the caveat that goes with anticipated lifespan associated with any piece of equipment:
“—if it is properly maintained and operated near the best/design operating point.”
All of this is not to say that it is impossible for individual pieces of equipment to operate beyond their anticipated useful life, especially with excellent maintenance. On the other hand, we can expect that poorly maintained equipment will fail long before reaching its anticipated useful life.
With an average age of a process plant in the neighborhood of around 50 years and the typical useful life of equipment in the neighborhood of 20 years, we should not be surprised to see that many pieces of equipment are operating well beyond their useful life.
Useful Life and the Bathtub Curve
As equipment ages, it deteriorates. As equipment deteriorates, it is more likely to fail. While the deterioration may be linear, the failure rate is not.
Instead, it follows the bathtub curve.
The bathtub curve, familiar to reliability engineers, is a plot of failure rate as a function of equipment’s age. The initial phase of the bathtub curve is a period of high but rapidly falling failure rates. It is sometimes referred to as the “burn-in” or “infant mortality” period. It is during this period that flaws in equipment and its installation reveal themselves. For consumers, a 90-day limited warranty is intended to cover the burn-in period.
After the burn-in period, the failure rate flattens out. The failure rate remains essentially constant. The equipment is deteriorating, but the amount of accumulated deterioration is trivial compared to most of the random stresses imposed on the equipment. The period of constant failure rate typically corresponds with what is known as the useful life: “the estimated period during which an asset is expected to remain in profitable service.”
Eventually, though, accumulated wear and tear catch up with pieces of equipment, to the point that the random stresses are increasingly sufficient to cause failure. The failure rate for the type of equipment begins to climb. This period is called the “wear-out” period. Typically, it is more gradual than the precipitous drop of the burn-in period. When a manufacturer says that their equipment has a useful life of 20 years, they are not saying that at 19.9 years the device is fine and that at 20.1 years it will suddenly fail. No, what they are saying is that at about 20 years, the failure rate will begin to climb noticeably.
Maintenance, Testing, and Inspection
An aging plant often faces financial pressures. Margins get squeezed as operating costs go up and the market forces prices down. Maintenance intervals get stretched. Annual maintenance turnarounds become 14-month turnarounds. When that doesn’t result in catastrophe (and usually it doesn’t), the next turnaround slips to 18 months, then to two years. Then three years. Then four. Things get patched as they break, but otherwise, testing and inspection slide.
Meanwhile, the equipment has slipped out of the constant failure rate period of the bathtub curve. The recommended intervals for testing and inspection, however, are based on being in the constant failure rate period of the bathtub curve. Beyond the useful life of the equipment, when it is in the wear-out period of the bathtub curve, the failure rate is increasing and the need for inspection and testing is increasingly urgent.
In the wear-out period, proper maintenance requires more testing and inspection, and more often.
Not less. No matter how much the private equity firm that recently acquired the plant is trying to squeeze the last drop of profitability out of the plant.
The Need for More, Not Less
Process equipment doesn’t last forever. Beyond its useful life, the length of which depends on proper maintenance, the equipment’s deterioration makes it increasingly vulnerable to the stresses it easily withstood when it was newer. At some point, one of those random stresses will be enough to result in a failure, perhaps recoverable, perhaps catastrophic.
The more aging plants depend on aging equipment, the more vulnerable they become to catastrophic failure. In an 1817 observation of Independence Day, an editorial in the Vermont Gazette admonished people to “let your motto be ‘eternal vigilance is the price we pay for liberty.”
Today, in a time of aging process equipment, it would be fair to also say, “Eternal vigilance is the price we pay for safety.” Let’s pay more attention, not less, to the condition of the equipment we’re operating.
