I’M HAVING PROBLEMS with my water pressure. It’s so bad, my girlfriend won’t stay with me because she can’t get the shampoo out of her hair. To make matters worse, if I run water in the kitchen while she’s showering, there’s absolutely no flow from the showerhead! We had a booster pump installed, but that didn’t seem to help much.”
Never let it be said that a plumber would stand in the way of romance!
With address in hand, I made the journey to his home, although it caused my truck to groan a bit. The last few hundred feet were practically vertical! No wonder he was under pressure to resolve the water pressure — at 2.31 ft. rise in elevation per lb. per sq. in. of water pressure, his home was lucky to have any water. I imagined the folks living at the bottom of the hill were relying on pressure-reducing valves to prevent their skin from being stripped away in the shower, while, at the top of the hill, the incoming pressure was a mere 25 psi.
Now 25 psi doesn’t sound too bad until you consider his master bathroom was perched like an eagle’s nest atop his three-story home and that we were in the basement, which added another dimension to the equation. If you round off each story height to 10 ft. and do the math, his water pressure in the master bath would only be 7.7 psi! In reality, it was closer to 10 psi due to the true height to the showerhead from the meter’s basement location being 34.5 ft. in elevation. No need for a foot ruler when water pressure change is known!
I had to chuckle (inwardly) when he showed me his “booster” pump. It was what we often refer to as a booster pump in hydronics — a standard cast-iron body circulator — one with a relatively flat pump curve. A downstream flow switch activated the pump immediately upon water being drawn.
As we talked about possible solutions, the owner told me he had complained to his builder regarding the lack of pressure. The response had been, “That’s what you get for building at the top of a hill!”
Next call was to the water company; its representative indicated it would be illegal to draw down the incoming pressure below 15 psi due to concerns about the immediate neighbors. I asked him if he’d ever read the Dr. Seuss story about the Star Belly Sneetches.
I told him I intended to sell this customer a 1-hp pump with enough suction to siphon out the neighbor’s toilets! Then I’d sell the neighbor a 2-hp pump and then this guy a 3-hp pump and so on until, finally, in Tim-the-Toolman fashion, we’d install 12-cylinder diesel pumps in each of their driveways to see which Sneetch could out-pump the other! In true utility fashion, the water company representative was not the least bit amused. Instead, he indicated an inspection would follow the installation.
We had a number of options available, however, and each brought with it its own set of challenges.
It would have been feasible to install an in-line centrifugal pump, not unlike the existing “booster” pump, so long as its pump curve could satisfactorily raise the third floor’s delivery pressure. Bronze-bodied or cast-iron pumps (rated for potable water) are both available for these applications, but I wasn’t quite comfortable with leaving a flow switch paddle in the water stream.
We’ve done that before with excellent results, but with ultra-low incoming water pressure and an admonition of potential fines for drawing the main line pressure too low, I wanted more precise flow control. Besides which, the owner was gun shy on any thoughts of in-line booster pumps.
There have been some excellent improvements in pump technology in the past few years, and the idea of using a constant-pressure pump was appealing. These pumps are compact and good at maintaining the set delivery pressure. The control modulates motor speed to match demand so quickly that a tiny expansion tank is all that’s needed to eliminate any noticeable pressure fluctuations.
In the final analysis, our customer chose the booster pump with expansion tank option. Not unlike a typical jet pump shallow-well installation, this system incorporates a tank with mounting bracket attached for the pump. A globe valve (with washer and bib screw removed) serves as the flow restrictor to prevent drawing down the incoming water pressure below the water company requirements (see the accompany drawing).
The bypass line allows for servicing the pump system without interruption of service or continued use of water in the event of a prolonged power outage. A downstream pressure-reducing valve stabilizes delivery pressure.
Romance was restored and they were engaged a month later. They may or may not live happily ever after, but at least they can get all the shampoo out of their hair!
Dave Yates owns F.W. Behler, a contracting company in York, Pa. He can be reached by phone at 717/843-4920 or by e-mail at [email protected].
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