Drip Irrigation Problem

[kaneohe]

I would like to drip irrigate a couple of plants while we are gone. Thought it was going to be straightforward but am encountering a problem: I wanted to install a pressure regulator but it appears that the simple fixed pressure regulators require a minimum flow of 10gph. If the flow is less than that, my impression is that the pressure will vary (I assume to higher than the nominal rating of 10 or 20 psi.) This is a Raindrip system.

The mini-inline drippers I was planning to use are only 0.5gph so 2 drippers would only be 1 gph. Any suggestions? Some random thoughts.....
there are 1 gph drippers available so run more of them. Use a variable pressure regulator..........do these not have minimum flow requirements; a lot more expensive than the fixed. Don't open valve fully & don't use the fixed pressure regulator........harder to control flow, what is effect on drippers of low pressure.

Ideally the solution works, reduces pressure to prevent the risk of leaks, is inexpensive, etc.

Thanks for your thoughts.

[padlin00]

Have you tried it at less then 10 gph flow? I've never had issues. I run 30 lb regulators. You can always call the manufacturer/retailer.

[kaneohe]

padlin00..........no I haven't yet......just trying to anticipate/avoid problems....
my concern is that if the regulator doesn't regulate and the pressure goes too high, the tubing/connections might leak or worse, get disconnected and discharge too much ......the flowers are in proximity to the foundation so trying to avoid that. I tried calling mfg but they seemed to be busy. Maybe I'll have to e-mail them. Thanks for the info.

[ERD50]

I'm curious, got a part number? I'm familiar with pressure regulators and I don't see why they would need a minimum flow (maximum limit, yes).

Generally, a diagram and spring close a valve to reduce pressure on the output side. Why would the valve need to remain open? Maybe they are just trying to allow for the valve not fully sealing, and leaking at a 10gph rate, even when closed? That would seem odd though.

-ERD50

[sailor]

Before we switched to my own pump, we used el-chepo pre-set plastic Raindrip regulators. While they are not lasting long (I've got typically two-three seasons out of one), they were cheap.
I had bad experience with plastic rain BIRD regulators - less than a season of use.
Many other companies make them, typically in $5-$10 range, like this one:
DIG Corp 25 PSI Hose Thread Pressure Regulator-D46 at The Home Depot.

My preferred external pressure regulators are brass RV type ( this one: Valterra Lead-Free Brass Water Regulator )- but they are typically 40-50psi and not 20-30psi. While 50 psi will work on Raindrip emitters, the emitters will not last as long, so go for 25psi.

BTW: If you need something really long lasting (think 30 years if protected from elements), use a "whole house" type regulator,
like this: Watts 3/4 in. Cast-Brass SWT x SWT Water Pressure Reducing Valve-25AUBS-DU at The Home Depot

As far as you question about regulators minimum flow - if there is not enough flow, most of them will still work good enough for the drip job, but can "buzz" (it drove DW bonkers) as they will open/close many times per second.
How many plants are you watering? For potted plants you could even use 2GPH drippers, as the potting soil is very quickly absorbing the water.
I also advise against using PC (pressure compensated) emitters as they clog much more easily (and you are going to use pressure regulator anyway).

[ERD50]

Quote:

Originally Posted by sailor .... As far as you question about regulators minimum flow - if there is not enough flow, most of them will still work good enough for the drip job, but can "buzz" (it drove DW bonkers) as they will open/close many times per second. ....

Thanks. I'm guessing that is due to the non-compress-ability of liquids (and very limited expansion in the hoses), you are essentially getting a 'water hammer' effect as it opens/closes. A larger flow would keep it at least partially open at all times, keeping it a linear range, rather than open/close.

A small air reservoir on the output (low pressure) side would probably smooth that out, but may have it's own problems, or just not be worth it.

-ERD50

[kaneohe]

Thanks , ERD50 and sailor , for your inputs. This is the Rainbird pressure
regulator http://www.raindrip.com/products/poi...-preset-20-psi
It looks similar in appearance and price as the DIG part that sailor showed.

There are only 2 flower plants so the flow will be low. They are in the clay soil so probably won't absorb as well as potting soil.

[sailor]

Yes, two plants is a small system. Do you happen to know what's your water pressure?
Maybe you don't need a regulator at all? While 25psi is "ideal" for drippers long life, it will work fine up to 60psi.