Question about water volume vs. pipe size and fitting size

[Greg Cary]

In the winter time I would like to use my 1" lawn irrigation water source to flood a skating rink located about 200 feet from the house. If I ran a 1" hose out to the skating rink, but I had a smaller diameter fitting in the middle of the run, would water volume be reduced very much?

Here is a description of my system: I have a 1" pipe that connects directly from my well to my lawn irrigation system. The pipe exits the house into a tee. One side (1" diameter) goes up to a shutoff valve, followed by some kind of pressure valve and then down into the ground to the irrigation system. The other side of the tee goes down about 6" to a standard garden hose valve. That valve is used in the fall to blow out the irrigation system with an air compressor. I want to use the garden hose outlet for flooding the rink. I understand that if I used a long run of a 3/4" hose, then the water volume would be limited. However, if I were to attach a 1" hose to the garden hose valve using the appropriate fitting, would volume be affected much by the smaller diameter valve? In electronics this would be like inserting a resistor, which would definitely affect the current flow. So the question is "how big is this resistor"? In case it matters, my well pump is capable of pumping about 20 gallons per minute. I could find out more specifications if necessary. By the way, in case you're wondering, I plan on blowing out the system from inside the house each time I use it (there are convenient air hose fittings in the pipe in the utility room).

I am a little concerned about getting water into the irrigation system even with the shutoff valve closed (such as if there were a tiny trickle of leakage). Any words of advice regarding this?

Thanks in advance for your help,

Greg

[running water]

. goes up to a shutoff

OK,, first if your worried about leakage back into the irrigation system,, add another ballvalve past the tee for the shutoff drain that drains the system, then you can shut it on and off as needed.

the shutoff /drainvalve itself is a reducer,, so unless you have a fullport open ballvalve shutoff, with some kind of full open gardenhose adapter on the end your reducing the volume right before you even run a garden hose of any diamter. so you would probably want to change the drain valve as well.

are you looking for a faster way to fill the skating rink? or concerned about the pump from your system running out of water?

[Greg Cary]

I was thinking about that. I would have two shutoff valves in series. I guess the process would be to close the first one while I'm flooding the rink and open it when I'm done. That way, water will not stay in the pipe between the valves and freeze. Always keep the 2nd one closed. I might have an issue with getting the 1st one to close if it freezes open. Maybe just keep both valves off all the time. If the pipe between the valves freezes and breaks, there would be no harm to the irrigation system.

I think you're answering my question, but not directly. What you're saying is any restriction in the line, no matter how short in length, will reduce the flow volume noticeably. Sometimes in practice there are other factors to be considered. Is it possible that the pump would increase the pressure because of the restriction? That would increase flow at the expense of the pump working harder. I am not a plumber and so I am looking for the simplest solution, which is using the existing garden hose valve with some screw-on adapters to get me back to 1". If the best solution requires getting the torch out or hiring a plumber I'll do that.

I am concerned about flooding the rink as quickly as possible. When the well was first installed they did not place the pump low enough in the well and the irrigation system did run it dry. They lowered it another 40 feet and there is no problem now of draining it. It can actually pump 25 gallons per minute straight out of the well, and about 20 gallons per minute out of the 1" irrigation pipe.

Greg

[kenny b]

don't use a ball valve if it's subject to freezing. kenny b

[Greg Cary]

What type of valve would be ok to use if it's subject to freezing?

I assume a ball valve is ok to use if you kept it closed all winter, right?

Greg

[running water]

why cant he use a ballvalve? decent ballvalves dont let water thru, if he drains the system correctly..how could it freeze?

[Greg Cary]

Thanks for your replies to my questions. A 1" irrigation pipe will screw on to the drain valve through the appropriate adapter fittings. The type of pipe I will use is that semi-rigid black stuff that comes coiled in a big roll.

I have decided to experiment with it since it will be easy enough to do and won't cost much to try. I tried to measure the flow out of the drain valve and I got pretty wet because it comes out with such force. It doesn't come out in a nice narrow stream because of the narrowing in the valve. As it comes out it fans out in a cone. The flow is actually very good. I measured about 20 gallons per minute, though I might be off a little because I couldn't start and stop my stopwatch and turn the valve all at the same time. I think it will be good enough. I can always do something about it in the future. My main concern would be water getting past the shutoff valve. I might hire a plumber to insert another one in series.

I learned a little about wells when the well driller had to come back and fix our well when our irrigation system ran it dry. Our well is about 300 feet deep. The bottom 30 feet or so is narrower than the first 270 feet. After they drilled down about 270 feet they switched to a smaller diameter bit to drill the last 30 feet. Then they put in

270 feet of well casing (PVC schedule 80?). The pipe bottoms out at 270 feet because of the narrower diameter of the well at that point. The bottom 30 feet is where the water seeps in. The productivity of the well depends upon what the earth is like where you drill the well. You might be lucky enough to hit an underground stream. Or it might be really dry sandstone and it might take a while for the water to replenish. The water in the bottom 30 feet actually pushes up towards to surface. Our well pump is not at the bottom of the well. In fact it is about 60 feet down below the surface. It was at about 20 feet until they lowered it. The well company had an employee that thought he knew better and said that 20 feet was all that was needed. He no longer works for them and they were being called back to a lot of installations where the well couldn't keep up with the demand. Bottom line, every well has a certain flow rate where you can pump continuously. Since the pump in my well was lowered, I have never had a problem pumping at 20 gallons per minute continuously.

As for ice rinks, I made a mistake last winter and let the hose run for about two hours (flow rate about 5 gallons per minute). My ice rink is actually a swamp that froze over pretty well last year. After the swamp froze, the water continued to drain underneath the frozen surface. That left a void. When I ran the hose for two hours it punctured a hole through the ice and for quite a while I had a hard time plugging up the hole. I eventually figured out the secret was to use a snow slush mixture to plug up the holes. This year I want to be able to put on a coat of water in short time. Instead of standing out there for 45 minutes, I should be able to get it done in about 10-15 minutes.

Greg