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clc19chase
08-06-2008, 11:50 PM
just added 4 zones to a lake pump system. my problem is while any zone is running the pressure is surging. the system consist of 1 1/2 suction running about 45 feet to pump. when lake is full the elevation change is only like4 feet max. right now the lake is almost 4 feet down. the pump is a 2 horse meyers with a 1 1/2 main running no more than 35 to 40 feet to the furthest valve (1 inch valves and laterals).... zone 1 consist of 13 rainbird 1804's (2 of them have 15' van at 360, and the other 10 are 15 vans at 210 degrees) This is a landscape redesign and the landscaper could have possibly damaged the main today with shovels. I thought it may have been a busted lateral but 2 new zones are performing this way. Is there anything that can happen to a pump to make it perform like this. when this surge is at it best pressure the heads are performing great but the low end of the surge the heads will start going down a little also.

hoskm01
08-06-2008, 11:57 PM
Sounds like a pump issue. Has the pump been maintained?

clc19chase
08-06-2008, 11:59 PM
probably not. I pulled the pump end down to see if debris might have been in it. but nothing. just brass impeller

clc19chase
08-07-2008, 12:03 AM
I must add that when trying to flush the lines before setting heads. the pump would not clear all of the cavitation with 13 funny pipes open. the highest funny pipe never got water but this same zone performed well 2 days ago after setting heads and before the landscaper arrived

Waterit
08-07-2008, 12:56 AM
You have an air leak on the suction side of the pump making it cavitate.

Wet_Boots
08-07-2008, 09:06 AM
Do some of the zones operate correctly? No pump issues? If so, that might suggest a problem with capacity, connected to the lower lake level increasing the suction lift.

clc19chase
08-07-2008, 09:43 AM
I will try the zones that were already there to see if they perform right. I guess it is hard to find an air leak on the suction line buried in the ground

Waterit
08-07-2008, 09:44 AM
I will try the zones that were already there to see if they perform right. I guess it is hard to find an air leak on the suction line buried in the ground

Yes it is, but it's more likely your leak (if there is one) is at a threaded joint.

h20 guy
08-07-2008, 07:10 PM
Agree with Waterit, a suction side leak will get you everytime, sounds like work to dig it up but most likely your problem.

cmrgrounds
08-11-2008, 10:23 PM
Im not to familar with pump systems but is it possible that you have to much pump or not enough heads on each zone to keep the pump running? I have a property where the homeowner had a 300 ft drilled well to supply water for the irrigation and the system would surge because there were not enough heads on each zone. The pump would cut off and back on at certain pressures and the sprinklers would surge. One minute the sprinklers were spraying good then they would be barely spraying at all. We had to add more heads to each zone to keep the pump from reaching the maximum pressure so it would stay running throughout each cycle.

CAPT Stream Rotar
08-11-2008, 10:29 PM
Dodge Ram 2500
1994 F-350 Dump Truck
8x16 Open Trailer
Gravely 52"
Exmark 60"
Walker Mt26
2 - Snapper Hi-Vac 21"
Stihl line trimmers
Echo/Stihl Edgers
2-Stihl BR600's
Stihl hedge trimmers
echo 16 ft limber
Johndeere 110 backhoe
More tools than you know
what to do with.


come on bro......

Mike Leary
08-12-2008, 12:03 AM
Im not to familar with pump systems .

Try spell check & hit delete on your sig., might have some luck on this site:hammerhead:

hoskm01
08-12-2008, 12:07 AM
Im not to familar with pump systems but is it possible that you have to much pump or not enough heads on each zone to keep the pump running? I have a property where the homeowner had a 300 ft drilled well to supply water for the irrigation and the system would surge because there were not enough heads on each zone. The pump would cut off and back on at certain pressures and the sprinklers would surge. One minute the sprinklers were spraying good then they would be barely spraying at all. We had to add more heads to each zone to keep the pump from reaching the maximum pressure so it would stay running throughout each cycle.
Either your pump was sized wrong or your pressure sensor was set wrong. Adding heads just to keep it running is absurd. How about two zones at once?

Waterit
08-12-2008, 01:31 AM
Im not to familar with pump systems but is it possible that you have to much pump or not enough heads on each zone to keep the pump running? I have a property where the homeowner had a 300 ft drilled well to supply water for the irrigation and the system would surge because there were not enough heads on each zone. The pump would cut off and back on at certain pressures and the sprinklers would surge. One minute the sprinklers were spraying good then they would be barely spraying at all. We had to add more heads to each zone to keep the pump from reaching the maximum pressure so it would stay running throughout each cycle.

Never even occurred to me to ask if there was a pressure switch involved - good point, guy.

So, is there a pressure switch on this system, clc19?

clc19chase
08-12-2008, 01:42 AM
no, no psi switch. I was there again setting heads yesterday. This problem is now very intermittent. I got there and fired up a zone I added and pump and pressure were normal, same zone that has been fluctuating. Fired up an existing zone (2 rotors and 2 sprays) pump and pressure are fine. Fired up these 2 zones again later after setting some heads on another zone. the problem is back. surging pressure and getting air in pump. still stumped on this one.

Waterit
08-12-2008, 02:08 AM
no, no psi switch. I was there again setting heads yesterday. This problem is now very intermittent. I got there and fired up a zone I added and pump and pressure were normal, same zone that has been fluctuating. Fired up an existing zone (2 rotors and 2 sprays) pump and pressure are fine. Fired up these 2 zones again later after setting some heads on another zone. the problem is back. surging pressure and getting air in pump. still stumped on this one.

Have repiped the suction side of the pump?

hoskm01
08-12-2008, 09:23 AM
an existing zone (2 rotors and 2 sprays)



Anyone see the problem there?

Welcome to Alabama.

clc19chase
08-12-2008, 09:24 AM
Have repiped the suction side of the pump?

no not yet

Wet_Boots
08-12-2008, 09:37 AM
A vacuum gauge is ever so helpful in diagnosing pump problems.

Dripit good
08-12-2008, 09:59 AM
Dodge Ram 2500
1994 F-350 Dump Truck
8x16 Open Trailer
Gravely 52"
Exmark 60"
Walker Mt26
2 - Snapper Hi-Vac 21"
Stihl line trimmers
Echo/Stihl Edgers
2-Stihl BR600's
Stihl hedge trimmers
echo 16 ft limber
Johndeere 110 backhoe
More tools than you know
what to do with.


come on bro......

ditto

Check your check (or foot). May be occasional prime loss?