Plumbing. Going from this fitting to that fitting, the hard way

[green.bubbly]

Starting the sheetrock on my house and decided I better pressure check the PEX lines before enclosing the walls. I needed to go from the 3/4" PEX to a compressor quick connect. Remember that I live in the country so the little hardware store down the road was my only option. 36 bucks and three trips to the store and I was in business.

Stopped by the house today after work and put it all together and connected it to my supply line. Filled up my little six gallon compressor tank to 100psi and dumped it into the line. Gauge showed nothing. Of course the cheap China made gauge shows 20psi with it just sitting on the table. Disconnected the tank and open the shutoff valve and there was no noticeable pressure in the line.

So my stupid question is how much air does it take to pressurize this a typical 1,800 sqft home? I know that is a difficult question to answer but it would seem that the six gallon tank should have created at least a little pressure. It was raining and getting dark so I could not go check if I might have an outside faucet open.

 

[strizzy]

Know how much pex you installed? A little high school math and we can figure it out pretty well.

Volume would be = Pi x (0.0625'/2)^2 x the length of Pex

Then: P1V1=P2V2

Pressure of the house = [120psi x (6gallon x 0.133680556 cubic foot/gallon)]/Volume above

 

[mrobins297aaa]

just wondering why don't you just turn the water on and check it?

 

[srmofo]

just wondering why don't you just turn the water on and check it?

I kinda agree with this.

I understand with copper because you have to drain the entire house down and then get the joints dry....but with pex, its just plug and play

Also when making a connector to the pex line , just use a ****** from your regulator, a hose clamp, a piece of extra pex, and tie it into the system with a pex connector.

 

[SGTH55]

City water is going to give you 65psi max most of the time (if it's a well you have to look at the tank setting). As with anything it could take more to fill it the first time. If it were me...turn on the water and look for leaks.

 

[rasit]

Gauge showed nothing. Disconnected the tank and open the shutoff valve and there was no noticeable pressure in the line.

Maybe, just maybe... you have a leak

 

[premierplayer]

just wondering why don't you just turn the water on and check it?

he's roughed in, well connection and tank not complete

take a small compressor to the site and charge it up, that's the way it's done

 

[green.bubbly]

he's roughed in, well connection and tank not complete

take a small compressor to the site and charge it up, that's the way it's done

Pretty darn close. I will have public water but it is still 150 feet away waiting for meter to be installed and trench dug.

I will go back one day this week and make sure the outside faucets are closed and pump it up some more.

Strizzy, I have no idea how many feet of Pex was installed. I think there are one of three things happening. Faucet open, big azz leak or just not putting enough air yet.

 

[Tim The Tool Man]

You must have a valve open or a big leak. Even with a small air tank like yours you would see an increase in pressure (unless you were filling a vacuum!). My guess would be that you have an open ended pipe or two. Go around and make sure every pex termination has a plug crimped in place.

Good luck!

 

[wnstwolf]

Green I did the same thing about 18 months back. My well was not in yet and the rough plumbing was complete with sheet rockers soon to follow. I used my small bostich pancake compressor and it took about 5 minutes to fill the line. I went to 75 pounds and left it there overnight. with pressure on I hit my test set up with some windex to make sure it was not leaking. Came in the next morning and I was down to 30 pounds. After a long battle it was the line going to the ice machine. the valve was about 80% closed allowing a very slow leak..
good luck your doing the right thing..

 

[NUTTSGT]

It'll probably take more air and longer to pump it up to pressure than you think. When new sprinkler systems are plumbed in (fire protection) they have to be pumped up to 200 psi and hold that pressure for 2 hours. It can take away to bring it up to pressure.

Granted, I realize you're not hitting 200 psi but your compressor might more oomph or time to build pressure. If it's leaking that much air, I would think you'd be able to hear it.

 

[BD1]

You only filled from a tank ? No compressor on it ? Tank only may put a little something, but if you got a leak, you gotta put a compressor on it to overcome the leak so you can either hear it or spray soap bubbles on it to check.

 

[green.bubbly]

Found my leak. Spare bath tub and shower not capped. Will pick up two tomorrow and try again.

 

[DHS]

Found my leak. Spare bath tub and shower not capped. Will pick up two tomorrow and try again.

They should only leak if the valve is on, correct?

 

[KenehPalmer]

As with anything it could take more to fill it the first time

 

[green.bubbly]

They should only leak if the valve is on, correct?

There is no valve body installed yet, just the sealed cap. Like this...

 

[green.bubbly]

Alright, pressured it up to 45psi Thursday night. Checked it again Saturday morning and it was down to 44psi. Saturday afternoon it was back up to 45.

Same thing today. This morning it was 44 and this afternoon it was 45. I am guessing the air in the lines is heating up and expanding during the day. Time to start closing up some walls.