The state is converting the road in front of the shop to multi-lane and have the water either off or low pressure several days a week. I have two 150 gallon tanks I'd like to make into constant pressure reservoirs. Would need two solenoid valves: one to fill tank and other to open to regulated compressor air line. Can the valves be wired so when the air supply to the tank is on the water supply has to be off? Thanks; Evan
Just got the message Evan. Have VFD business to deal with until 8:30 or so. I'll get you a drawing later tonight. I'm assuming voltage should be 110 AC. What is the size (in NPT) of the lines from water and air supply?
First, I'm no plumber and none of this is probably up to code. The check valves shown in the drawing are drawn as electrical diodes, but then diodes and check valves both do the same job, just in a different media. Diodes operate on electrical flow while check valves operate on fluids like water or air. This option works with no electricity. That is the upside. There are two down sides. First, if the water supply from the city is out for long enough for you to use all the water in the tank you will begin running compressed air through the water system in the building. Makes noise. May break crud loose in the piping that clogs up screens in aerators, etc. Assumption is that street water pressure is normally 60 psi. When pressure in the tank falls below 30 psi air from the regulated supply starts pushing on the surface of the water at 30 psi to move water through the building as required. The check valves are cheap, usually in the $10-15 range. When the tank is being used on "air" power and city water returns the tank will refill until the internal pressure reaches 60 psi. Depending on the water level in the tank when city water begins flowing the level in the tank once 60 psi is reached in the tank could be as little as half full. If you put a "bleed valve" (a simple hose bib) in the line coming into the top of the tank you could manually crack it open until water (instead of air) flowed out, completely filling the tank with water.
If you'd be willing to cut a hole near the bottom of the tank to put a float (level) switch into the tank a girl could easily rig an electrically controlled valve in the air supply line that would shut off the air supply when the liquid level in the tank fell below the level of the switch. If the electrically controlled valve was like the ones you use on an air compressor it could "unload" the air pressure from the tank. If you want to go that far let me know and I'll draw that up.
Or better yet, the float switch could control an electric valve in the output to the building water supply, closing the line when the water in the tank gets low. This would prevent air in the building plumbing lines.
For the bleed valve, would a vent for a hydronic heating system do the job, automatically? While most of the US heats with FHA, the Northeast is firmly rooted in FHW. The bleed valve I mention lets out air, but not water. Just a thought.
I thought of that, but I don't think it would do the job. You could mount one low in the tank and use the escaping air as a warning that you were about to run out of water.
Thanks, Bill, You answered several questions, the valving and what the pressure should be on the air line. A 60 psi air regulator is probably one I have on hand or easy to find. Our pressure washer we use for washing the paint booths down gets ahead of the supply when the city WP drops and actually sucks the supply hose shut. First I'll run a regulator up to 60psi and see if the tank can take it (with the tank on the far side of a big dirt pile) and then put a hose outlet where the 3/4 npt drain plug is, fill with 150g water and fire up the washer. If 150g does the job, and I think it will, then no need for the other stuff. If not then your schematic is easy to follow--thank you; Evan
When you pressure test the tank fill it completely with water, then pressurize it with air. That way when it blows there will just be a small amount of compressed air and mostly non-compressible water in it. Not near as exciting when the tank fails. That 60 PSI number is what my house gets from my local MUD. As they say about mileage, "Yours may vary".
THANK YOU, Used your advice on pressure testing and also used a junk dump truck from the salvage yard to set the tank down in so just in case it blew the shrapnel would be contained. Used your KISS method before doing all the valving and found 150 gallons is more than enough to pressure wash a paint booth. Just a pressure hose on top and feed hose out of the bottom. May keep the set up even after the city pressure is back being dependable. Thanks again; Evan
Evan, Pictures or it didn't happen. I figured I'd beat Zig to it (that's Zig, the mattress-delivery guy).
Ziggy could make a few bucks renting his truck out to the ladies of the night in the red light district across the river in KC MO.
The girl I dated in high school became a Braniff stewardess (not flight attendant then) in the late 1950's and was stationed in K.C. There was a popular song at the time called "Kansas City" ( lyrics: 14th and Vine, got some mighty little pretty girls there and I'm going to find me one". When I visited of course I wanted to go to 14th and Vine and was surprised my friend readily agreed. When we got there the "Ladies" were strutting in high boots, hot pants, and long strap purses. Of course she had to spread the word all around about my prime tourist attraction.
You'll have to try a new neighborhood the next time you go Evan. According to this map I found on the internet (so it must be true) the red light district is now west and a little north of 14th and Vine, which is signified by the big X.
HA!!! Bill... You must have too much time on your hands... I'm pretty sure if I had my truck up in KC, I might get a few thumbs up. Some kind of playoff game to be going on up there Sunday night.
Not that I'm a huge fan, but there is one going on here tomorrow. We are not likely to advance. And Evan has the lyrics wrong. It wasn't "14th and Vine", it was "12th and Vine", a corner that hasn't existed since the 1960s when an urban renewal project led to much of 12th Street east of The Paseo, being razed. The song was written in the early 1950s.
