very high head self priming pump

[MikeHolm]

I'm looking for a self priming water pump. It needs to be able to self prime from about 10m and produce about 15-20L/min flow. It is just for cold water from a tank. Unfortunately I cannot put a well pump in it. any ideas?

I should have said "very high priming ability pump"

[install monkey]

self prime of 10mtr- mike u dont want much,can you not fit the pump under the tank to eliminate the self priming?

[install monkey]

mike ive found 1 that will self prime 9.5mtr if this helps-are u sat down as i dont think its cheap
http://www.environmentalpumping.co.u...sheet%20R9.pdf

[MikeHolm]

Ohhh, thats funny. I forgot about peristaltic pumps but that one won't even fit in the room let alone the 2nd one I need as a backup.

[install monkey]

mike normally u fit the tank at the highest point ie 10mtr,then use a booster pump set connected via a float switch in the header tank with a hi limit float to cut out when full,then u eliminate ur self priming req and have a standard pump with a small tank

[MikeHolm]

I know. The problem is that this is a new school (2nd in a series) and they wanted to use rainwater for toilets and kitchen steam washers. The "engineers" who did the first school refused to look at the report that said there should be a pump in or near the bottom of the tank. They stuck a couple of booster pumps 8m above the bottom of the tank at grade (idiots) with no primary pump.

I would fire the buggers right away but i am trying to make the best of the situation. The tank is buried so inaccessible.

[install monkey]

if u fill the tank with 8mtr of agregate then the tank will only be 2mtr deep and the pumps might work,-normally in that application submersible pumps are used as they are ip65 rated

I know. The problem is that this is a new school (2nd in a series) and they wanted to use rainwater for toilets and kitchen steam washers. The "engineers" who did the first school refused to look at the report that said there should be a pump in or near the bottom of the tank. They stuck a couple of booster pumps 8m above the bottom of the tank at grade (idiots) with no primary pump.

I would fire the buggers right away but i am trying to make the best of the situation. The tank is buried so inaccessible.

[MikeHolm]

Not able to do that, i fear (aggregate). I will be getting the plans for it soon, then we will see.

[stufus]

What about installing foot valves (nrv) on the tank outlets and a main's priming loop controlled by differential pressure switch on the suction side if the pumps.
The tank has to be accessible for maintenance and cleaning so filters on the foot valves can be cleaned as part of PPM inspections .
Cheers
Stu

[install monkey]

http://www.google.co.uk/search?q=arc...4BT4T4GMaf8gOZ
think you might have to resort to the archimedes principal
http://youtu.be/of-14LGhx60
if a couple of annoying kids can make 1 then im sure mike can knock up someting

[chemi-cool]

Ventury air pump will do the trick for you. Something like that:
http://forum.grasscity.com/do-yourse...en-dinner.html

[Brian_UK]

10m NPSH is about the limit for regular pumps without accounting for pumping losses. I think that they need to dig some more holes to fit some pumps into.

http://www.engineeringtoolbox.com/np...ead-d_634.html

[monkey spanners]

Surely at 10m you'd need near enough a perfect vacuum to get any water sucked up the pipe?

Why not just pressurise the water tank and push it out

Or,

http://www.youtube.com/watch?v=_nFh_...eature=related

[Magoo]

Check a diaphragm pump. every farm here has one for water supply to house with a pressure compensation tank after the pump. Down side is they can be noisy.

[mikeref]

Guessing somewhere around 67psi pressure needed to bring the water up 10m There is and old windmill on a farm not far from here that is still functioning. Takes all day to fill an above ground tank though .

[MikeHolm]

Many good ideas here. Hopefully I'll be able to post the plans when I get them so you all can have a laugh. I think Chemi is letting us in on a little secret past time LOL.

I don't think there are foot valves as the current pumps won't hold a prime for more than a few minutes.