I’ve recently set up a 50 gallon rain barrel and connected it to a 1/10 hp hose pump to water some nearby planters every morning (see pictures below). When the barrel is close to full, there’s some static pressure and I’m getting continuous dripping out of the irrigation line when the pump isn’t running. Ideally I want water to come out only when the pump is running.

What can I add to the line to prevent the dripping unless the pump is on? I tried looking for some sort of “minimum pressure” valve but couldn’t find anything, not sure if that exists. Something passive would be preferable so I don’t have to add another electronic component to the system.

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  • Are you doing anything about dry running? I have a similar little pump and it warns that running it dry will cause damage.
    – KMJ
    Nov 3, 2022 at 16:24
  • 1
    The easiest solution is to use that shut-off/drain valve.
    – crip659
    Nov 3, 2022 at 16:42
  • With some explanation of how that would work, @Ruskes, that could be an answer.
    – FreeMan
    Nov 3, 2022 at 17:55
  • I have a water level gauge in the barrel that prevents it from running dry.
    – Guillochon
    Nov 3, 2022 at 18:41
  • 1
    See gardening.stackexchange.com/q/34549/6806
    – Ecnerwal
    Nov 4, 2022 at 12:55

2 Answers 2


Thanks to @Ecnerwal for suggesting spring checks, I found an adjustable one that is perfect for this particular application, the Hunter Sprinkler HC75F75M HCV:

enter image description here

It can be adjusted by twisting, default "crack" pressure (the pressure at which flow begins) is 5 PSI, but you can adjust it up if necessary. The pump I have produces about 15 PSI of pressure, so at the default setting it flows when the pump is on, but not when the pump is off.

The only issue with this particular valve is that it has NPT threads, so I needed some GHT adapters to connect it inline in my system, which is all GHT. Ideally something like this specifically for GHT would be better, but I couldn't find anything out there.


The pump has no shutoff valves.

So if you increase the inlet pressure it will leak true it.

The more water is in the barrel the higher the pressure on the pump inlet.

The pump uses simple spinning rotor to pump. Water can also go true it without pump running.

If you elevate the pump to let say 1/3 of the barrel hight that should work.

For that you need to replace the expensive high pressure metal hose with longer regular garden hose.

Alternatively use physics:

..lead the watering hose above the barrel then down to the planters, so the pump has to push it up, and due to difference in water level it wont run if the pump is not running.

  • The issue with elevating the pump is that when the water level is low, no water gets to the pump.
    – Guillochon
    Nov 3, 2022 at 18:47
  • 1
    not necessarily, the pump has also suction capability
    – Traveler
    Nov 3, 2022 at 19:38
  • But it’ll necessarily run dry at first until it sucks water up into itself, which doesn’t seem great for the pump. I’d be happy to swap out the pump for one with a shutoff valve, if such a thing exists.
    – Guillochon
    Nov 4, 2022 at 4:19
  • @Guillochon see update in my post
    – Traveler
    Nov 4, 2022 at 5:11

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