How many times have you stepped into your motorhome shower only to be disappointed by anemic water flow? Typically, this scenario presents itself when hooking up to campground water. Although most campgrounds have good water pressure, the use of a regulator in front of the hookup hose ensures that excessive pressure won’t damage the motorhome’s lines and fittings. And that’s the rub: The use of a common pressure regulator – while reducing campground water pressure to around 45 psi -restricts flow too much.
Standard-type, inline regulators generally sell for $10 and are available at almost all RV stores and campgrounds; they are designed to reduce pressure from 40 to 50 psi. Even though they can restrict water flow, technically they work as designed – at least for a while. There are other options, including the use of a freer flowing, adjustable water regulator that allows the user to dial in suitable pressure (although it’s usually preset to 45 psi).
A quick visual inspection will tell you why the flow is restricted in the standard regulator: The holes are tiny compared to those in the adjustable version. To find out just how restricted these regulators are, we performed back-to-back tests.
For our first test, we hooked up the standard Valterra regulator to the faucet – and attached a gauge that showed it reduced pressure to 38 psi (lower than its advertised 40-50 psi range). We then connected a 5/8-inch hose and timed how long it took to fill a bucket with two gallons of water (we premeasured and marked the bucket). After doing the math, the flow rate for the standard regulator was 9.55 gallons per minute (gpm).
Then we performed the same test using a Valterra adjustable regulator, touted to be free flowing. It was set at 45 psi, and provided a flow rate of 11.39 gpm, or a 19.27 percent improvement in flow.
To find out how that relates to real-life use inside a coach, we hooked up to the city water fill from the same outside water faucet and performed the back-to-back tests, running water from the kitchen faucet. With the standard regulator, the water flowed at 1.78 gpm versus 1.99 gpm using the adjustable regulator. This amounted to an 11.8 percent improvement in water flow.
The adjustable regulator is almost five times as costly as the standard version, but it
will probably last longer, and makes a considerable difference in water flow, which relates
to better showers – something that was obvious under practical, under-the-showerhead tests.
Adjustable regulators with dial gauges are also available in most RV stores, including Camping World.