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Thread: Pump outflow port size

1. Pump outflow port size

Newbie here...

I just purchased a cottage property on a lake. The lake is the water source and the water system was working when I took possession. However, after shutting down the hydro panel after a visit the pump lost prime during the week. I suspect a problem with the foot valve which I will change. I want to change the set up so I can prime it easier but I forgot to measure the size of the outlet port so I can pick up the parts before heading north for the weekend.

The pump is a Mastercraft 3/4 hp. By the way, vertical lift from the lake to the pump is about 12 feet. The pressure tank is at the cottage about 100 ft up a 45 degree hill.

I couldn't find specs for this pump in the internet, but I'm guessing the outflow port size is known to veterans on this forum.

I plan to put a valve above the elbow for priming. There is a valve above the pump with a piece of garden hose attached which I presume was use to verify that the pump was primed and pumping, but that might not be its purpose.

Any advice and suggestions would be greatly appreciated.

I hope these pictures taken during inspection help...

2. Given the Hypotenuse of 100 feet and the angle of 45 degrees, I calculate the rise to be 70 feet. At .43 PSI per foot, you are losing 30 PSI at the cabin. I would suggest that you change out that jet pump for a submersible.

Anyway... that was not the advice you came here for. To prime the pump after replacing the footvalve, I suggest you pour the water into the pipe up at the cabin and bleed off any air at the hose bib near the pump.

3. I believe that is a 1" elbow on top. You can change that out to a tee. Then you can put a valve or a plug in top of the tee for priming. With 30 PSI loss going up the hill, I am not sure that pump can get to 50 PSI at the tank for shutting off. If it can't shut off, you will need to lower the setting of the pressure switch to maybe 20/40.

4. Thanks for the info. I didn't really want to hear that advice to prime at the cabin. That's a long way to carry water uphill by the bucketfull, but if that's what it takes, that's what I'll do. I don't recall seeing a valve for this purpose but I can install one. Someone (not on this forum) suggested I needed to prime from just above the pump down to the foot valve and the pump could push the water uphill from there. That's probably not true.

When the system was working I didn't notice the pump coming on an unusual amount, so I think the system is basically ok except for (I'm guessing) a leaking foot valve. Once I get it primed and running I might leave the power to the pump on until I drain the system for the winter. I don't like leaving the pump on when I'm not there but once I get it primed I don't want it to drain out again.

What's your opinion about leaving the power on for a week at a time when no one is there?

5. Originally Posted by tedr
Thanks for the info. I didn't really want to hear that advice to prime at the cabin. That's a long way to carry water uphill by the bucketfull, but if that's what it takes, that's what I'll do.
I went on the assumption that you could drive to the cabin and not have to cart water by hand up the hill. A 30 PSI head on the pump would make for easy priming.

I would put a shutoff at the tank inlet and turn off the power. Then the tank will be a nice reservoir to prime the pump.

6. Originally Posted by LLigetfa
I went on the assumption that you could drive to the cabin and not have to cart water by hand up the hill. A 30 PSI head on the pump would make for easy priming.

I would put a shutoff at the tank inlet and turn off the power. Then the tank will be a nice reservoir to prime the pump.
LLigetfa:

I really appreciate your help. I can drive to the cottage so, yes, I can bring water with me. I'm not sure how much I need, but I can figure that out. There is a shut off valve a few feet above the pump on the cottage side that I could close before turning off the hydro. I didn't know what it was for, but it would keep water in the long supply line as well as the tank.

Before running water in the cottage I could start the pump and see if water is available at the hose bib just past the pump. If so, no problem. If not, could I simply open the shut off above the pump and let the water line and tank back fill the pump and the supply line to the lake? Maybe wait a minute, then start the pump?

I'm sorry about all the questions - I'm pretty good at some other things but clearly have a lot to learn about pumps and plumbing.

7. Ja, the 100 feet of 1" pipe could supply 4 gallons of water for priming via gravity plus whatever there may be in the pressure tank.

8. Valveman presented the best and simplest solution
I believe that is a 1" elbow on top. You can change that out to a tee. Then you can put a valve or a plug in top of the tee for priming. With 30 PSI loss going up the hill, I am not sure that pump can get to 50 PSI at the tank for shutting off. If it can't shut off, you will need to lower the setting of the pressure switch to maybe 20/40.
.
Keep it simple, if it worked before it should work again. Prime it at the pump through the Tee that you need to install.
I'd install a low pressure cut-off Pressure Switch in place of the regular switch and leave the pump electrical on until you need to drain it in winter. The low pressure cutoff Pressure Swicth will shut the pump down in the event of lost prime or ruptured line when you are not there.

9. Thanks again LLigetfa, Valveman and Porky. Here's my plan:

First I will replace the foot valve. Then I'll install a Tee at the pump for priming. If I get water flowing at the pump (through the hose bib) I'll see if it will fill the line to the cottage and the tank. If it does, then I'm back in business. Then I'll look into the low pressure cut off switch. In the meantime I'll turn the power to the pump off when I leave but I'll trap the water in the tank and the water line so that if I lose prime again it may be easier to prime.

If I can't get the system to work using the Tee at the pump then plan B will be to prime the pump and the entire supply line from the cottage on the hill to the lake.

If that doesn't work then plan C is to hire an expert, but I really hate to do that. It's not the cost, I just like the satisfaction of learning and figuring things out.

I'll be trying this in a week and a half from now and I'll report back on how successful your student was.

Thanks again for sharing your knowledge.

10. Where in Ontario is this cottage? I'm guessing since you call it a cottage, it is Southern Ontario cuz up this way we call it a camp.

Instead a mechanical low pressure cutoff switch, give some thought to a EPS15/99. A mechanical switch may trip during power failures. They may also be prone to false trips if drawing too much water They can be a PITA for a novice to reset. The lever has to be held "just so" long enough to clear the threshold. Jostle it and you short cycle the pump.

http://www.cyclestopvalves.com/products.html

11. LLigetfa:

Yes, in Thunder Bay it would be a camp. Ours is between Bracebridge and Huntsville so it magically becomes a cottage.

12. We just got back from the cottage but we were unable to get the water system sorted out. When we arrived the power was out, apparently due to damage from high winds although we still aren't sure what happened. Anyway, the power never did come back on so we couldn't run the pump. Fortunately we had brought lots of water with us from home so we were still able to enjoy our visit.

We'll try again next weekend.

13. Well, the good news is I got the water flowing. The bad news is I'm not sure of the precise steps required.

I discovered a T in the line up on the hill under the cottage just before the pressure tank. My initial plan was to install a T at the pump outflow down by the lake. I decided to begin by following Lligetfa's suggestion of priming from the cottage rather than at the tank. I closed the valve just above the pump and poured about 10 gallons of water into the water line using the T near the pressure tank. Then I went down to the pump, opened the valve to let the water run backward through the pump. Then I started the pump. The pump sounded like it was drawing air.

There is a hose bib between the shutoff valve and the pump. I shut off the valve and opened the hose bib - no water. I opened and closed these valves numerous time and started and stopped the pump to keep it from overheating. Sometimes water gushed out of the hose, but I'm pretty sure that was just the water I had poured into the line earlier, not water from the lake. After messing around for about 15 minutes I eventually got the pump to work.

My theory is that I didn't wait long enough for the water in the line to backfill the pump and supply line. In my mind I could picture the water running into the lake all at once. It may be that it leaks back slowly through the pump. By the way, I didn't replace the foot valve because I'm pulling the line out of the lake next weekend anyway. But I did close the shutoff by the pump to retain water in the system so I can test whether this would make priming easier next time.

Anyway, we got water. Thanks again for all the advice.

14. A final update...

This past weekend we visited the cottage. During the previous night the temperature had dipped below freezing so I was pretty worried that I might have a broken pump. I opened the hose bib and turned on the pump and slushy, near-frozen water gushed out. So I closed the hose bib and opened the shut-off just uphill from the pump and had water flowing in the cottage almost immediately. I'm not sure why, but the pump didn't lose prime this time.

I'm lucky the pump didn't freeze. Before we left for home I pulled the water line out of the lake, removed the intake and outflow lines from the pump and removed the drainage screws from the pump. I also removed the foot valve to drain the intake line. I drained the hot water tank, filter and pressure tank, and blew out all the lines. I poured some plumbing antifreeze into all the traps. I guess I'll find out in the Spring how well I did all of this.

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