Sandpoint Sprinkler System Issue

[Pcapes]

Sorry if this gets lengthy, it has been a frustrating ordeal.
We have a sandpoint well, 24' down, last year had 12' of water in pipe. We run a 2 hp motor, for 10 zones, 6-7 heads a zone. This had been working wonderful for years. A few weeks ago one of the zones that has no heads was accidentally turned on for 12 min. This happened while we were sleeping, so we never saw it till we got up. By then pressure had built up and blew our lines off our pump. Water was still pumping out the pump.

We hooked it all back up, we get water to all heads, but not enough pressure to pop them up.
Put in new solenoids, diaphragms, etc. No luck.
Then took the pump off and looked inside, it was cooked, so put the new rebuild kit in it. Pump motor sounds fine. Put the pump back on and we can only get 10 psi coming out of the pump, no leaks we see. Again not enough pressure to pop the heads up. At this point, we had thought the pump was the problem, now we are completely out of ideas. Any thoughts would help.
We are considering checking the water level again, but not sure why that would be the issue when it was working just fine.
Any ideas?? Thanks!!

 

[WorthFlorida]

Is this a jet pump or an irrigation pump (sometimes called a centrifugal pump)? I'm assuming it's an irrigation pump.
Did your rebuild kit include a new impeller and I assume the pump shaft seal was replaced? Is the pump housing glass or metal?
When things blew up it was not from excess pressure but from heat. The water can get incredibly hot in this situation. Most impellers are a plastic or glass like material and it might have warped. Possible but doubtful with a glass housing that it distorted. You did what I would have done except that the valves would not had to be rebuil

I had a three horse pump where a contractor was using it for water and turn off the 2" ball valve to the sprinklers but left it in the close position. After the job was done, the timer was still set in the AUTO position so during the night the pump turned on. In my case the 2" pvc pipe between the pump and ball valve got so hot that it expanded to about 4". One giant bubble. I never knew PVC could do that. Fortunately the pump housing was all cast iron and no damage to the pump. There was a pressure relief valve (not temperature) installed but it never opened.

 

[Sponsor]

 

[Pcapes]

Is this a jet pump or an irrigation pump (sometimes called a centrifugal pump)? I'm assuming it's an irrigation pump.
Did your rebuild kit include a new impeller and I assume the pump shaft seal was replaced? Is the pump housing glass or metal?
When things blew up it was not from excess pressure but from heat. The water can get incredibly hot in this situation. Most impellers are a plastic or glass like material and it might have warped. Possible but doubtful with a glass housing that it distorted. You did what I would have done except that the valves would not had to be rebuil

I had a three horse pump where a contractor was using it for water and turn off the 2" ball valve to the sprinklers but left it in the close position. After the job was done, the timer was still set in the AUTO position so during the night the pump turned on. In my case the 2" pvc pipe between the pump and ball valve got so hot that it expanded to about 4". One giant bubble. I never knew PVC could do that. Fortunately the pump housing was all cast iron and no damage to the pump. There was a pressure relief valve (not temperature) installed but it never opened.

 

[Pcapes]

It is an irrigation pump. The rebuild kit did come with a new impeller and all the seals. Housing is metal. Ya I thought after rebuilding it that problem would be solved. At a loss at this point.
Ya the pressure build up is amazing, and causes lots of issues.

 

[Reach4]

A vacuum gauge at the input of the pump could help diagnose. Be careful not to add a vacuum leak while adding one in.

I think it is common to need to drive a new sand point after some time.

I have no relevant experience.

 

[WorthFlorida]

About the last thing ? Did you inspect the check valve that it is opening all the way?

 

[Pcapes]

About the last thing ? Did you inspect the check valve that it is opening all the way?

No we have not done that yet....good idea.
Would it keep its prime if that was the case?

 

[WorthFlorida]

If the check valve was stuck open it would lose prime. It is on the suction side so pressure or heat probably did not affect it. Just something to check anyway. If it was affected when things broke, the spring might have distorted and it's not opening very much. One reason why Reach4 suggested it. What a good reading would be on the suction side is hard to say since pump and pipe size affects the reading.

 

[Pcapes]

If the check valve was stuck open it would lose prime. It is on the suction side so pressure or heat probably did not affect it. Just something to check anyway. If it was affected when things broke, the spring might have distorted and it's not opening very much. One reason why Reach4 suggested it. What a good reading would be on the suction side is hard to say since pump and pipe size affects the reading.

Ok that is a great thing to at least look at. Thank you all for your input.

 

[Bgard]

check for vacume leaks where the suction line connects to the pump. it can suck air but still not leak any water, and prevent the pump from being able to pump at it full capacity.

 

[Pcapes]

check for vacume leaks where the suction line connects to the pump. it can suck air but still not leak any water, and prevent the pump from being able to pump at it full capacity.

Not to sound dumb but how would I go about checking for a vacuum leak?

 

[Reach4]

Not to sound dumb but how would I go about checking for a vacuum leak?

In the search box above, enter "shaving cream" with the quotes.

I wonder how aerosol whipped cream would compare. Probably not as effective, but you could eat the leftovers.

 

[Valveman]

Run a wire through the jet nozzle. Probably have something stuck in it.

 

[WorthFlorida]

Not to sound dumb but how would I go about checking for a vacuum leak?

While the pump is running, run water over the pipe connections from the well to the pump. If there is a leak water could get sucked in and the sound of the pump would changed to where it is pumping 100% water instead of air and water.

 

[WorthFlorida]

Run a wire through the jet nozzle. Probably have something stuck in it.

He has an irrigation pump. No jet.

 

[Valveman]

He has an irrigation pump. No jet.

Thanks! Then it is either a suction leak, bad pump, or out of water.

 

[WorthFlorida]

Not to sound dumb but how would I go about checking for a vacuum leak?

Here is a tutorial that is pretty good explaining irrigation pumps and wells. I'm sure you're familiar with most of it but it did have a table for needed pressure of an irrigation system. You'll need about 40 PSI. How are you measuring pressure? This is my favorite guage that you put on a spigot. I always install a spigot at the pump to help prime the pump and allows to run a garden hose off the pump if spot watering is never needed. Turn the red dial to zero and run the pump, the gauge needed will push the red needle and leave it at the highest pressure measured. This is great for a water heater tank to measure max pressure on water expansion. You can leave it on the hose bibb (house water) with the bibb left open overnight you can get the max pressure to your home. It's also call a tattle tail gauge.

http://www.irrigationtutorials.com/pump2.htm
http://www.homedepot.com/p/3-4-in-Plastic-Water-Pressure-Test-Gauge-DP-IWTG/100175467

 

[Nellie Toole]

If you are using a sprinkler in your garden, and your sprinkler cap can't working properly, then you can replace it. If you don't know how to replace it then you can check given guidelines.