Drip from my Sprinkler back flow drain

[CharlieV]

I just noticed a drip coming from my lawn irrigation back flow drain. The water is shut off for the winter and the system has been blown out. I have a 1/4 turn ball valve. Do I need to replace the valve or will tightening the packing nut help?
Also, there isn't a leak around the valve itself, just at the drain outside.

Thnaks

 

[Taylorjm]

I'm not sure where you mean it's leaking. Do you mean the ball valve has a little drain on it? Or your backflow preventor setup has a leak?

 

[Sponsor]

 

[WorthFlorida]

A picture would help on the type of backflow preventer or model number. Where it is dripping, is it because of water pressure behind the drain valve or the system is still draining? Is this drip inside the home or above grade?

https://aquaprosprinklers.com/wp-content/uploads/2014/07/BackflowPreventerDrainingProcedure.pdf

 

[CharlieV]

The drain below the backflow. I'll post a picture in a little bit.

 

[CharlieV]

A picture would help on the type of backflow preventer or model number. Where it is dripping, is it because of water pressure behind the drain valve or the system is still draining? Is this drip inside the home or above grade?

https://aquaprosprinklers.com/wp-content/uploads/2014/07/BackflowPreventerDrainingProcedure.pdf

It is above grade. On the backflow preventer.

 

[CharlieV]

Below are photos of the valve inside and the backflow outside where the drip Is at.

 

[Taylorjm]

So is it just dripping from that little drain at the bottom of the elbow? That's just pipe thread. Take it off and put some teflon tape on and tighten it back up.

 

[CharlieV]

My water is turned off for the winter. I think the shut off valve has the issue.

 

[Taylorjm]

My water is turned off for the winter. I think the shut off valve has the issue.

Ahhh, now I see what you mean and why all the pictures of the inside too. So you think the inside ball valve is leaking because the drain on the outside has water in it. So have you loosened the little drain on the ball valve on the inside of the house and let all the water drain out from the system, then wait and see if it fills back up? Honestly I know it's not impossible, but I don't ever recall seeing a ball valve like that one leaking when it's shut off. I've used many, many ball valves over the past 30 years and don't recall ever turning one off and having it leak enough for me to notice. Maybe over the course of a few days, some does leak past them and that's what your seeing, but I never had an issue with turning one off to do some repairs and have an issue like that. It is possible that whoever sweated that valve on originally got it too hot and melted some of the internal seals. That's why there's a nut in the middle of the valve, because the valve is in two pieces and can be separated to remove seals before sweating them. I've never done it because I know how to sweat them properly, but you never know. I know some industrial valves have teflon seals in them and you need so remove them before sweating too close to them. There's really no way to replace the seals without taking the valve apart, which is probably not possible unless there's a union close by. Then will you be able to find parts for a valve like that? If it is leaking your only choice is to replace the valve.