House main shutoff, how to tell direction of flow?

[themartb]

Hi,

As a new resident of Orlando FL, so I'm new to the idea of the meter being out in the street, and the shutoff valve inside the house being just completely plain, unmarked cheapo pvc ball valve.

I want to install a whole-house filter but looking at the main water shutoff valve in the garage, there is no apparent way to tell which side is the incoming supply from the street, and which side is outgoing to feed the house. It's just a pipe the comes out of the wall, has a valve, then disappears back into the wall again! Fwiw, it's a vertical arrangement, maybe there's a code standard where the bottom is the supply (coming up from pipes in the foundation slab?), but I have no clue.

The only way I can think of is to shut it off out in the street, cut out the valve in the house, then (with the wife standing by with a bucket), slowly crack open the valve in the street until I get yelled at for water going everywhere ... out of one or the other pipe.

Just wondered if anyone has any saner ideas cheers,
-mart

 

[breplum]

no code standard. PVC is not allowed inside buildings in most codes. Reason (I think) is that PVC becomes brittle with age and is prone to breaking.

 

[Twowaxhack]

If the water main enters the garage from the yard at this point then I would think the lower pipe would be the main coming in.

You can figure out what pipe is the main when you’re installing the filter. Just turn the main off and bleed the pressure off. Cut the pipe in the garage above the valve. Turn the valve off and then go crack the meter valve on just a hair.

Then go to the garage and see which pipe is the main.

 

[themartb]

Seems like I was at least in the ballpark with my idea, but I'm seeing now that the details of the execution can be finessed to keep things a little more orderly.
I could perhaps drill a hole in each pipe that is directed at the floor to make collection easier during the test (I plan to replace the valve with a brass swing-handle one so some of the pipe near the current valve is toast anyway). Or, if I end up deciding to install gauges (before & after filter), maybe I could even set them up temporarily on each pipe to see which gets pressure.

Thanks @Twowaxhack.

@breplum, do you mean PVC shouldn't be used within the structure of the house, in very permanent locations where it can't be replaced? (vs just 'indoors' generally)

 

[Twowaxhack]

Yeah or use another person while your on cell phones and crack the meter valve a hair. 5 gal bucket, whatever. You’re only going to have a trickle or maybe none at all if the valve in the garage does what we believe it does.

Pvc isn’t allowed inside the walls of the foundation by most plumbing codes. Its just not reliable enough.