Water Hammer - Far from the source

[Rossn]

My home is a few hundred feet from the street, where it has city water supply and a meter at the street. About half way between the house and street I have a yard hydrant at the garden, which currently has some drip tape hooked up to it on a timer and with a 10psi pressure regulator.

With the lower level of the home gutted (where the water supply enters), I can hear significant water hammer and rushing water sounds when the water starts flowing, even though the yard hydrant is directly attached to the supply line leading to the house, mid-way from the street.

Can anyone help me understand why i can hear this, given it is over 100' from the house, and tapped prior to the home? How does one manage this?

 

[OLD TIMER]

I hope you have a vacuum breaker on that yard hydrant. is the timer a quick closing valve? how much water is the drip tape using? does the water hammer happen when the timer opens or closes the valve?

 

[Sponsor]

 

[Rossn]

There isn't a vacuum breaker integrated or on it, so I make sure that before the hydrant is turned off, it is disconnected from the hose. It pretty much stays on all summer. I did look for them last year, and it seemed all the cheap ones were rumored to not work well. Do you have a particular product you recommend?

As to the valve, it's a $20 orbit battery operated hose bib-connected timer valve, not an in-ground system. The hammer noise occurs 100' beyond this point, within the house when the valve opens, and you can hear the rushing water (the most surprising aspect) which tapers down until you cannot hear it... presumably while the drip tubing is filling.

I don't have a flow rate, but likely after the drip tape fills the rushing sound is no longer heard. There's probably around 7 rows of 5/8" drip tape at 75', and maybe 1/2 of it is turned on currently? Each row has a valve and my wife is doing the gardening this year.

 

[Reach4]

I would try a garden hose thread flow control / Dole valve / flow restrictor / flow regulator rated for some appropriate GPM.
such as https://www.conservationwarehouse.com/outdoor-spigot-water-controller.html

 

[Rossn]

Ah yes, forgot a minor detail. I should have remembered that there is a 10 psi pressure regulator downstream of the valve. I'll also look into the flow control, though is it needed if there is a pressure regulator?

 

[Reach4]

Yes. They do different things. I am not sure which should go first. I am thinking flow limiter first, and then regulator.

If you are in electronics, one would be analogous to a voltage regulator, and the other would be like a current limiter.

 

[OLD TIMER]

it sounds like, when the drip tape comes on it steals the pressure and water from your pipe that's between the yard hydrant and the house which would explain the water hammer and rushing water. I can only guess because I am not there.
that's a lot of drip tape. Water hammer While the drip tape fills sounds right.
high pressure always flows to low pressure.

 

[OLD TIMER]

That's all you need. take the screw out. it is meant to break off when you tighten it.
if it breaks off you'll never get it off the hydrant.

 

[WorthFlorida]

If it’s copper pipe from the meter to the house, copper is a good conductor of sound, like most metals.