When we checked in at the Salt Lake City KOA, we were warned about high water pressure. They told us that the water pressure can run up to 120 psi here. Our escort told me a couple of horror stories of hoses blowing up like balloons and plumbing leaking inside of coaches.

It’s not unusual for municipal water companies to run high pressure through the main water supply lines. Sometimes it can be as high as 200 psi! They need high pressure to supply high rise buildings or other elevated  dwellings. Building codes require inline water pressure regulators to prevent lines from bursting, causing damage and potential for injury.

WalMart, RV Stores and some RV parks sell cheap brass restrictors that they call regulators. This is very misleading and somewhat dishonest in my view. I noticed our neighbor hooking one up when he pulled in today and I thought I should post something about it.

Back in 1738, a fellow named Daniel Bernoulli published a treatise called Hydrodynamica. In this publication, he gave us Bernoulli’s Principle.

Without going into fluid dynamics equations, I’ll give a simplified explanation of why these restrictors should not be called regulators. Bernoulli tells us that when a fluid flows through a restriction, velocity of the fluid increases. When velocity increases, pressure decreases.

The brass restrictor in the photo above provides restriction in the water supply to the RV in question. When a faucet or shower valve is open and water is flowing into the RV, the restrictor causes the velocity of the water to increase as it flows through the restriction and the water pressure drops. So far, so good, right?

I see two problems with this set-up. First, the restriction reduces the amount of water coming into the coach. The flow rate may not keep up with the demand at a shower head, for example. This is an inconvenience.

The second issue is more than an inconvenience – it’s a recipe for disaster. When the faucets and shower valves are closed, water no longer flows through the restrictor. No flow, no Bernoulli Principle. Pressure will equalize on both sides of the restrictor. Now you have unregulated static water pressure. Whatever the pressure is on the input side of the restrictor is equal to the pressure on the output side. The plumbing inside the RV is at full main pressure until water starts to flow again. Not a comforting thought as you lock up your RV and head out for the day.

What’s needed is a proper pressure regulator, such as a Watts regulator (also called a water pressure reducing valve). This is what’s used on residential plumbing. The Watts regulator is a true regulator. The pressure will remain at the specified setting, regardless of flow. It also doesn’t restrict the volume of water. The 3/4″ Watts regulator that I use can flow over 30 gallons per minute with the pressure cranked down to 25 psi! I keep mine set at 45 psi.

The drawback to the Watts set-up is cost. You can get the restrictor type for about $12, but remember, it doesn’t protect your plumbing when the water isn’t flowing. I think I spent about $80 for a residential watts regulator and fittings (I posted about it here). To me, it’s worth it, because I know I won’t have my plumbing blown out by excessive pressure.

While Donna was out bicycling yesterday, I brought the ladders out. I used the smaller ladder to debug and clean the windshield. The Brillo Bug Scrubber has become a new favorite product. It cleans bugs off glass effortlessly.

I used the big ladder to climb onto the roof. I lubed the gears on the TV antenna (it was getting almost impossible to crank up and down) and checked the holding tank vents. The way the vent covers are attached and caulked into place, I couldn’t inspect visually. I probed the vent tubes with a long plastic zip-tie and didn’t find any obstructions.

When Donna returned, we emptied the contents of the refrigerator and freezer into coolers and turned off the unit to defrost it. RV refrigeration isn’t frost-free. We have to perform this task every few months. Donna says it’s a great excuse to clean the refrigerator.

I prepped the trailer for travel. Everything is set, I only need to load and tie down the scooter this morning.

Last evening, Donna prepared blackened Baja fish tacos for dinner – one of our favorite dishes. They were so good!

After dinner, we took a walk through the park. We talked with a couple that are on their first extended RV trip. They’re new to RVing and are having a blast. I’m starting to feel like an old hand when I talk to people who are just starting out and have many questions that I’m able to answer.

We saw a couple of interesting rigs. The first was a fifth-wheel trailer and what made it interesting was its size. It couldn’t have been more than 20 feet in length. It’s the smallest fifth-wheel I’ve seen. I bet it’s really maneuverable.

Then we came across something totally unique. It was an old Mercedes Benz truck chassis converted to an RV. We met the owners and talked with them briefly. They’re from Austria. They started their adventure in Buenos Aires, Argentina and have made their way to the US. Their trip will take them to Alaska. Once they reach Alaska, they’re undecided on what to do or where to go next. I didn’t get their names. Between their rudimentary English and my pidgin German, we barely communicated.

We’re moving out this morning. We plan to stop overnight in Idaho, somewhere between Pocatello and Idaho Falls. Tomorrow, we’ll set up in West Yellowstone, Montana. I may not post for a day or two, depending on Internet access and time available.