Wow! Twenty years of great reading in Plumbing & Mechanical.

Happy Birthday, PM! It has been a great run for a magazine. Since the beginning, I've looked forward to receiving my copy of the magazine that has kept me informed for all these years.

I started thinking about all of the changes that have taken place in the past 20 years. When you look at changes on a regular basis, it doesn't seem like much has happened. But, when you look at a period of 20 years, you start to marvel at the progress we have made.

Twenty years ago, no one in the United States knew what cross linked polyethylene - PEX - was. Today, PEX is second to copper tubing as the most-used material for water distribution systems. It is also the dominant piping material for radiant heating systems.

The second most-used piping material in 1984 was polybutylene. That, of course, is no longer installed.

We also had the start of a piping system called a “manifold system.” Today, PEX manifold piping systems are one of the most popular water distribution systems for residential installations.

I developed a laundry list of changes that have occurred since the first issue of PM magazine was published:

Air admittance valves were introduced to the United States in 1986. There were none installed until 1988. What started with one company has now expanded to seven manufacturers of air admittance valves.

The number “1.6” was between 1.5 and 1.7. It had no association with a water closet, or flush volume. In 1984, many jurisdictions were mandating 3.5-gallon per flush water closets. Others continued to permit 5-gpf water closets.

Shower flow rates were being lowered to 3 gpm across most of the United States. It was sometime later that they were lowered further to 2.5 gpm.

Lead was still in solder. Chicago required water service pipe less than 2 1/2 inches in diameter to be lead pipe. While a lead solder ban was being discussed, it wasn't until another four years that it was mandated by the federal government.

Women had the same number of plumbing fixtures as men in major stadiums, halls and arenas. Hence, women had to wait in line much longer than men. “Potty parity” was not a term in our vocabulary. We have come a long way. Anyone visiting these new facilities will immediately notice the difference. (My wife and daughters are very grateful for this change.)

Residential sprinklers were thought to be an interesting idea, but something off in the future. Today, the building codes mandate residential sprinklers for all residential buildings more than two stories in height.

The copper industry was the big player and major proponent of the sovent system. You can no longer find a copper (brass) sovent fitting. The only sovent being installed is cast-iron.

The term “through penetration protection” was not a part of a contractor's vocabulary. No one knew what was necessary for penetrating fire-resistance-rated floors and wall assemblies. Today a contractor can identify the penetration by the cost of the protection system.

Pull-out spray faucets were something you would find in Europe; they weren't permitted in the United States because of backflow protection concerns. It would take nearly 10 years for the standard to be published that regulated these faucets.

Backflow protection was not required for water supply connections to automatic fire sprinkler systems. Eventually, double check valve assemblies would be mandated by the plumbing codes.

There was no such thing as a drain line carry test. Everyone knew that when you flushed the toilet, everything went down the drain without any problem.

The plumbing codes only permitted two water closets to discharge to a 3-inch drain. The International Plumbing Code no longer has this arbitrary limitation. You could possibly have 12 water closets on a 3-inch building drain under the IPC.

A building with numerous floor drains often had oversized drains because of the fixture unit value increase associated with the floor drains. The codes now identify an emergency floor drain as having a fixture unit value of 0 dfu. Hence, floor drains do not impact the size of the drainage system.

You had to flush your own toilet or urinal. You also had to turn on the water by yourself. Now the water closet flushes by itself, and water comes out of a faucet when we place our hands under the spout. It's right out of the “Jetsons.”

Ceramics was a class that ladies took; it was not a material for faucet seats.

Handicapped plumbing fixtures were only provided in new buildings. In existing buildings, a person using a wheelchair had to fend for himself. The term “ADA” did not exist.

When around an open drain, plumbing contractors didn't worry about AIDS or SARS. Those were terms that also were not a part of a contractor's vocabulary.

Various plumbing products still had asbestos in them.

Water heaters would blow up if you placed a vat of gasoline near them. (OK, so this one is new as of last July, but it is still a major change that has occurred in the last 20 years.)

Copper was soldered. Press fittings had not been invented for copper tubing, even in Europe. Whoever thought that 4-inch copper tubing could be joined to a fitting in four seconds? Amazing!

You had to use primer when joining CPVC. One-step solvent cement was a nice idea, but had not made it out of research.

Customers weren't buying faucets at Home Depot or Lowes.

A toilet seat did not clean itself automatically.

Gate valves were the dominant full flow valve. Ball valves were occasionally installed. The opposite is true today. Something I am thankful for.

Plumbing history made the History Channel, thanks largely in part to PM and our great editorial director, Jim Olsztynski.

I am sure you can add some additional advances made in the industry. It has been a wonderful 20 years. I took forward to the next 20 years. Just keep reading PM; we'll keep you abreast of the changes in the industry.