Pumo Query

[lannarebirth]

I've got a 6.5 hp Honda motor that drives a centrifugal pump to send water to various tanks from a pond on my land. One section of the land is pretty steep and the tank is 300 meters away from the pond and 30 meters higher. The centrifugal pumps output is greatly reduced by the head so I had to get a positive displacement pump to marry to the 6.5 hp motor. The centrifugal pump has a 2" outlet, so consequently I have several hundred meters of 2" black hose to use with it. The pos. disp. pump has a 1.5" outlet. So, here's my question. Any problems using the 2" pipe on the discharge side of a positive displacemnt pump with a 1.5" outlet? I wouldn't think so, but thought I'd ask those perhaps more knowledgable on the subject. Also, I guess I should put in some check valves on that 300 meter run lifting 30 meters. Any idea how many I might need or how far apart they should be placed? TIA for any responses.

edit: The editing feature should really let you fix muffed thread titles.

Edited February 12, 2008 by lannarebirth

[PhilHarries]

No problem with the swage up in line size, as it's a positive displacement pump it squirts so much volume per stroke regardless of the volume it is squirting into. Normally such pumps have a pulsation damper and relief valve but these, if required, will almost certainly be built into the unit.

As for the check valve only one is really required mounted at the pump discharge but if you are worried about losing the tank contents in the event of hose rupture it, or a second NRV, could be mounted at the tank inlet.

[chownah]

I found this site which has a pump installation check list....I thought it might be helpful in general for people who have pumps:

http://extension.oregonstate.edu/catalog/pdf/pnw/pnw293.pdf

Chownah

[Gary A]

I've got a 6.5 hp Honda motor that drives a centrifugal pump to send water to various tanks from a pond on my land. One section of the land is pretty steep and the tank is 300 meters away from the pond and 30 meters higher. The centrifugal pumps output is greatly reduced by the head so I had to get a positive displacement pump to marry to the 6.5 hp motor. The centrifugal pump has a 2" outlet, so consequently I have several hundred meters of 2" black hose to use with it. The pos. disp. pump has a 1.5" outlet. So, here's my question. Any problems using the 2" pipe on the discharge side of a positive displacemnt pump with a 1.5" outlet? I wouldn't think so, but thought I'd ask those perhaps more knowledgable on the subject. Also, I guess I should put in some check valves on that 300 meter run lifting 30 meters. Any idea how many I might need or how far apart they should be placed? TIA for any responses.

edit: The editing feature should really let you fix muffed thread titles.

I think you should buy new smaller hose and sell the two inch hose to me.

[lannarebirth]

No problem with the swage up in line size, as it's a positive displacement pump it squirts so much volume per stroke regardless of the volume it is squirting into. Normally such pumps have a pulsation damper and relief valve but these, if required, will almost certainly be built into the unit.

As for the check valve only one is really required mounted at the pump discharge but if you are worried about losing the tank contents in the event of hose rupture it, or a second NRV, could be mounted at the tank inlet.

Thanks Phil. That's what I thought about the line pipe size but knew someone would know for sure. Wasn't at all sure about checkvalve placement so thank you for that too.

Ken

[lannarebirth]

I found this site which has a pump installation check list....I thought it might be helpful in general for people who have pumps:

http://extension.oregonstate.edu/catalog/pdf/pnw/pnw293.pdf

Chownah

Good link chownah, thanks.

[lannarebirth]

I've got a 6.5 hp Honda motor that drives a centrifugal pump to send water to various tanks from a pond on my land. One section of the land is pretty steep and the tank is 300 meters away from the pond and 30 meters higher. The centrifugal pumps output is greatly reduced by the head so I had to get a positive displacement pump to marry to the 6.5 hp motor. The centrifugal pump has a 2" outlet, so consequently I have several hundred meters of 2" black hose to use with it. The pos. disp. pump has a 1.5" outlet. So, here's my question. Any problems using the 2" pipe on the discharge side of a positive displacemnt pump with a 1.5" outlet? I wouldn't think so, but thought I'd ask those perhaps more knowledgable on the subject. Also, I guess I should put in some check valves on that 300 meter run lifting 30 meters. Any idea how many I might need or how far apart they should be placed? TIA for any responses.

edit: The editing feature should really let you fix muffed thread titles.

I think you should buy new smaller hose and sell the two inch hose to me.

There never seems to be enough pipe does there. If one bought pipe and fixed pipe in place for every possible irrigation configuration it can be a huge capital outlay. Consequently I try to buy pipe and pumps that have the most cross utility I can. Still, I'll probably need 1,000's of meters of 2". 1.5" and 1" hose. It's kind of a pain as many shops have now switched to metric pipe size, which don't quite match up. Also it takesup a lot of space as I can't bury it if I'm trying tyo stay flexible and save money. I buy about 100 meters a month and just work it into my regular global house expenses, so it doesn't hurt too bad all at once.

[Maizefarmer]

Considering some of the distances and elevations you are talking about here lannerbirth you don't by chance have a small tractor?

[lannarebirth]

Considering some of the distances and elevations you are talking about here lannerbirth you don't by chance have a small tractor?

I do as a matter of fact. A Kubota L2602DT.

[slapout]

lannarbirth. If they are going to metric size pipe I would check the thickness of the wall of joints. This is a indication of saving on manufactoring cost, and I have experienced loss of quality on some of the pipe put on the market under these conditions.

[Maizefarmer]

Considering some of the distances and elevations you are talking about here lannerbirth you don't by chance have a small tractor?

I do as a matter of fact. A Kubota L2602DT.

Good little unit with loads of torque.

Bin the 6.5hp Honda pump and go buy yourself a pump down at the local ag supply store - weld up a stand that can be moutned on the 3point hitch - mount the pump on the stand and gear it up/down accordingly with some pulleys and fan belts to be driven off the pto shaft - and you will have a very efficient portable pump that will do just about whatever you want it to do

[ozzydom]

Considering some of the distances and elevations you are talking about here lannerbirth you don't by chance have a small tractor?

I do as a matter of fact. A Kubota L2602DT.

Good little unit with loads of torque.

Bin the 6.5hp Honda pump and go buy yourself a pump down at the local ag supply store - weld up a stand that can be moutned on the 3point hitch - mount the pump on the stand and gear it up/down accordingly with some pulleys and fan belts to be driven off the pto shaft - and you will have a very efficient portable pump that will do just about whatever you want it to do

MF,I did a similar thing with our Kubota iron buffalo,made up a mounting frame for the front and bought a bare 3" centrifigal pump ,it chugs away all day for next to nothing compared to the Honda petrol driven 4".

[lannarebirth]

Considering some of the distances and elevations you are talking about here lannerbirth you don't by chance have a small tractor?

I do as a matter of fact. A Kubota L2602DT.

Good little unit with loads of torque.

Bin the 6.5hp Honda pump and go buy yourself a pump down at the local ag supply store - weld up a stand that can be moutned on the 3point hitch - mount the pump on the stand and gear it up/down accordingly with some pulleys and fan belts to be driven off the pto shaft - and you will have a very efficient portable pump that will do just about whatever you want it to do

MF,I did a similar thing with our Kubota iron buffalo,made up a mounting frame for the front and bought a bare 3" centrifigal pump ,it chugs away all day for next to nothing compared to the Honda petrol driven 4".

Thanks MaizeFarmer and ozzy. That's an excellent idea, but probably not one I will implement right away. I'd probably have to move up to a 3" or 4" discharge hose which would be pretty expensive for the quantity I'd need. Prbably by then I'll have electricity on site, so I'm just adapting what I have the most of for right now. After rainy season I'll take another look at it.

[Maizefarmer]

I'm in the dairy in a few hours time - and will load up some examples of 3point hitch mounted pto driven pumps - will give you an idea for frame construction and pulley positioning as you are almost certainly going to have to impliment a a setup with at least 2 pulleys (more than likely 3 though) to achieve a good drive ratio between the pump and pto shaft speed. Don;t forget to use a double/twin belt and pulley setup, so if one snaps it doesn't bring the show to a standstill till you get another belt.

There really is little that beats the efficiency of a pto shaft on a small tractor to pump water - their engine torque is incredible enabling to move really large volumes of water against big heads.

Speak to Kirloskar in Bangkok - they have a nice range of small centrifugal pumps that do what it says on the tin - nice and light, great for frame mounting and belt drive through the pto shaft, and overall good value for money (far better than the chinese <deleted> you find in ag stores)

Just remember - run the tractor engine at max torque throttle setting - not max hp throttle setting - much more economical for the same volume (especialy against high heads) and as it inevitably means lower engine speed, means less engine wear and tear.

[Beardog]

I found this site which has a pump installation check list....I thought it might be helpful in general for people who have pumps:

http://extension.oregonstate.edu/catalog/pdf/pnw/pnw293.pdf

Chownah

Good link chownah, thanks.

Killer link ! Thanks for finding this info & passing it on!

[Lickey]

LB, my set-up is borehole, holding tank then booster pump, 240mtrs to top of farm, 3inch 1 yard rise, {all electric operation with 1hp borehole and 2hp cetrifugal 2in out booster pump }last year i had a problem where the booster pump was throwing the switch out, and it was a new pump, it had a 1 way valve fitted near the pump, I reasoned that the pump had to fight against 240mtrs of head and open the valve as well, thus blowing the switch, so i put another vavle 100 mtrs from pump and before leaving farm, would drain the 100 mtrs off into fruit trees ect, never had anymore problems, This year i only irregate at night, on a timer, it seems the power supply is better and ive renewed the booster pump switch, but the check valves are still in place, cheers, Lickey..

[chownah]

I reasoned that the pump had to fight against 240mtrs of head

Lickey,

I think you forgot to convert running metres of pipe into metres of head. Assuming you have a constant slope of 3 inches per yard (which is 1 in 12...or about 8%) then the total head from the pump to the top of your land would be 20 metres of head. Also, note that this is the "elevation head" which is the head due to the difference of elevation between the surface of the water source at the pump and the surface of the discharge at the top when discharging to a ditch or tank. For pumping purposes it is probably best to consider the total head....which means to the elevation head you need to add the pressure head needed to run the sprinklers at the top and also the friction head for the water flowing through the pipe which will depend on the flow rate of the water through the pipe, the kind of pipe, the length of the pipe, the diametre of the pipe, and the number, kind, and quality of fittings in the pipeline.

Chownah

[Lickey]

Hi Chownah, thanks for your reply, and from your previous posts i know you are a competant water 'engineer' I understand a bit of what you are getting at, But since we planted a new 12 rai with bananas and papaya ive had to extend the pipes another 300 mtrs downhill form the top of farm, with 3 40 mtr pipes with outlets for sprinklers, the lowest sprinkler keeps working even when pump has stopped, I was hoping this would syphon water from the uphill rise but it doesent, probaly because of the sprinklers further up the hill, hence fitting the check valve 100 mtrs from pump, ideally i would like to fit and ADV [automatic drain valve ] near the pump, same as an air brake system on big truck, with no pressure, it will open, and drain tank, getting rid of sludge ect, under pressure, it closes, would be ideal !! if there is such a thing for water pipes, i want one!! Cheers, Lickey..

[Maizefarmer]

You're quite right - the sprinklers open the loop.

The correct way to do it is to insert a brass check valve on/at the pump outlet (free hinged, not sprung - so the pump doesn't have to fight it), followed by a PVC T-piece with a manual or adjustable spring loaded PVC ball valve on the T - all avalible from your friendly local hardware stall.