Pump priming problem

[cw4Bray]

I'd like to water my garden from a nearby river with a 2" pump. I want to keep the pump at the top of the bank, because the bank is very steep, 10 vertical feet . I don't have a foot valve for priming. I've got a 1.5" venturi which I'm pondering glueing to a two inch pump. I know the simplest and surest way would be to place the pump on a raft down low in the water and maybe that's the correct answer.
To access the water, I could build some steps into the bank.
I've also got a cheap chinese diaphragm pump that I could use for priming but it struggles lifting 10' as the plastic handle bends under the strain of the vacuum.

Will it work ? How much draft lift can I expect from a 1.5" venturi ?

 

[Joe H]

Permanent pipe up from river with check valve at the bottom end ?

Water well type ck valve

 

[Willie B]

Use a wet vac for priming.

 

[cw4Bray]

Thanks !! The Foot valve makes the most sense but I'm trying to get by without it.
I tried using a Shop Vac but it struggles to lift eight feet even with a leak proof tight seal.

 

[cw4Bray]

The first picture might need another vavle or cap at the top of the tall vertical priming tube. This is to vent the drafted air From the venturi, but then once primed it needs to be closed to the pump discharge.

The second picture would be a configuration using a one inch hand operated diaphragm pump. In this configuration I'd put the pump down close to the water. What do you think ?

 

[reganj]

My .02,, Pump is to pump water to water storage tank close to garden.
Big enough water storage tank and you will only have to run pump every once in a while.
Pump is not made to suck water up 10 foot.
Place pump as close to water as is safely possible. Enjoy.

 

[SLK001]

Thanks !! The Foot valve makes the most sense but I'm trying to get by without it.
I tried using a Shop Vac but it struggles to lift eight feet even with a leak proof tight seal.

You really need a foot valve for your setup, especially with it so far above the river. Why are you so hesitant to install one?

 

[Willie B]

Thanks !! The Foot valve makes the most sense but I'm trying to get by without it.
I tried using a Shop Vac but it struggles to lift eight feet even with a leak proof tight seal.

Without a check valve at the bottom it won't be simple. Having the intake in the stream vertical open on bottom might help. I've done it easily with a shop vac even higher. Water weighs about .0335 LBS per cubic inch.
There is no such thing as a vacuum, only the absence of pressure. If a vacuum cleaner were the most powerful imaginable, atmospheric pressure could theoretically push water up 36 feet in elevation to the pump.
Vacuum must T into the outflow above the pump.

 

[Vetech63]

When I have a pump priming problem, I find that an extra cup of coffee and some good morning stretches can get me there. It helps if the wife is wearing som....................oh wait........

 

[cw4Bray]

I love my stainless steel coffee mug. It was a Christmas gift from a son inlaw. It's got double wall vacuum insulation. It changes the taste of coffee as it slowly cools.

When I have a pump priming problem, I find that an extra cup of coffee

 

[cw4Bray]

The venturi seems like magic. Any experience you could share with drafting venturi's would be greatly appreciated. What size have you used ? Are you drafting from more than a flatbed truck ?

I'd like to run the open suction line unrestricted open near the river surface on a float.

Maybe I'm looking in the wrong home improvement store, the foot valves I've seen at the hardware store max out at 1.5" for a sump pump check valve or 2" for a sewage backflow valve.
I'm trying to reduce resistance and cavitation, especially on the suction side. Overcoming the spring pressure is more resistance. Anything less than 2" is an impedance for my application.

If HEF says foot valve is needed, I could make one on my 3D printer. Then market the; "6 inch fat Bob foot valve" ?

 

[SLK001]

You can pick up a 2" PVC foot valve for $15 on Amazon.

 

[cw4Bray]

You can pick up a 2" PVC foot valve for $15 on Amazon.

Interesting online shopping. Thanks SLK, That 2" foot valve is about the equivlent of 1" valve - once it goes through the curve of the valve frame. So $15. isn't going to do it.
A 8 inch valve is $500. ouch !
I can use city water for three summer months for less than that, if I amortize over the remainder of my already long life, it doesn't pencil out.

 

[SLK001]

Okay, so what are you really watering? Is your garden a 50' by 50' plot, or is it 40 acres? Your intake is still only a 2" pipe, isn't it? Even with an 8" foot valve, your pipe is still 2" in diameter. Your pump is capable of pumping greater than 100 GPM.

 

[cw4Bray]

It is a 50' X 50' plot with every type of produce you can think of. Been watering from a 100 year old hand dug well but it goes dry after July.
The city water we drink from just doubled the rate$ so it makes sense to improve the water source.

SLK, I'm from the (tool time) Tim Taylor school of more power. When I get tasked by the "war department" to water tomato's or potato's I don't want to stand around "gently sprinkling" for one hour with a 150' long 1/2" garden hose from a one KW electric pump. I think I can get the job done faster with a 1.5" hose from a three KW Gasoline pump.
Also I'd like to be able to drill a new well with the 1.5" line that I need lots of water to drill with.

I've also been thinking of digging instead of drilling. I've got several short sections of 18" pipe that I could use for a well. I've got a Bobcat 418 that I'd copy what Spud pulled off. What a cool trick that was !

The 2" pump is really old and weak, it may have been 200 GPM when new, but not when pushing 500' of 1.5" line

 

[SLK001]

Have you seen the stream from a 100+ GPM water hose? Think "flash flood". It will scour everything in its path. Instead of watering your garden, you'll be digging up everything and pushing it away from you into one giant heap.

You'll need some way to slow the flow down, like installing an above the surface sprinkler system.

In an application like this, bigger is not better.

 

[cw4Bray]

Have you seen the stream from a 100+ GPM water hose? Think "flash flood". It will scour everything in its path. Instead of watering your garden, you'll be digging up everything and pushing it away from you into one giant heap.

You'll need some way to slow the flow down, like installing an above the surface sprinkler system.

In an application like this, bigger is not better.

Sounds great for drilling a 3" diameter PVC well !

 

[terex herder]

check out exhaust primers. From what you describe they will work.

 

[Willie B]

check out exhaust primers. From what you describe they will work.

Fire trucks used to have exhaust primers. When I was a teenager our small volunteer fire company still had one old truck with one. It was difficult to pull prime. Two spots where we put the truck on a bridge & lifted 15 or more feet in elevation to get prime, it was difficult at best.

My in laws had a system much like what we are describing. They did have 1" suction pipe with a cone shaped screen/foot valve. It needed priming once a year. A funnel was used to get water into a port on top of the pump. Fill it up, screw the plug in, turn it on, good for the summer.

 

[cw4Bray]

This pump had been used to bail out flooded basements. It had a 1" reducer on the 2" intake port, which seems almost criminal on the suction side.
I'd like to get 30 PSI at idle or 1000 RPM, I'll experiment to see if that's possible..
On a different note,
This primer pump, (for my 2" gas powered) was only $10. but struggles to lift 8' - 10'... However, it does a good job of pumping sewage from a boat.