Could I change my main water valve without a plumber? (NYC)

[skald89]

My main water valve does not turn and off properly. No matter which way I turn the handle it will not tighten. Our water pressure is low because of this, where only one thing can be open at a time.
In NYC there is a shut off valve in the side walk with a metal cap. Home Depot sells a key to open and close it. I have almost no experience with plumbing. The most I have done is change shower cartridges and changed the stopper in the bathroom sink. Looking at the valve it looks like I would at most have to open the piping before and after the handle and replace that while installing a new valve, like this this or this one.
Album of valve and pipes

 

[James Henry]

I know it will cost about $ 15,000.00 in NYC to replace that valve but your safer to hire a plumber.

 

[Sponsor]

 

[DIYorBust]

Unless you're very confident you can do this, and it doesn't sound like you are, I think this is a good one to call in a plumber for. You can tell by my name and avatar that I'm not easily swayed in this direction.

If something goes wrong, you could end up with water coming in and no way to stop it. A plumber will have the right tools, knowledge, authorization, and insurance to handle this sort of situation.

 

[Dj2]

Blame De Blasio.

 

[Stuff]

What do the plumbers here think about using shark bite fittings on a main valve?

 

[Michael Young]

I'm not comfortable at all with using a sharkbite. At the very least, break out the ol torch. This is your main line coming in. It has to be perfect.

 

[Jadnashua]

FWIW, the main curb shutoff may not work properly. That could complicate things considerably.

I had a similar problem, and did end up using a SHarkbite as it would have taken hours for all of the other things on that line to drain out, and I wasn't confident one of the things used to temporarily block the pipe so you can solder (cannot solder with any water...drips, or flow will not allow the pipe to get hot enough until all of it is gone). Some use bread, but there are some higher tech devices. So, I cut the pipe, cleaned up the edges (while some water was still leaking), pushed on a Sharkbite valve that was closed, and then soldered everything past that that was dry.

You asked whether you could...some of the question may better be may you. My guess is no. Do something incorrectly and you could be affecting the health of numerous people on that supply line path. Can you, don't know you. The liability could be significant.

It sounds like you may have a gate valve and the stem has broken so you cannot move the gate up or down.

 

[DIYorBust]

I would not use a sharkbite, but faced with the situation jadnashua described I think I would use a press fitting.

If the valve is a gate valve, it may be possible to rebuild the valve, but this would be difficult if the street valve doesn't fully close, and not necessary if the street valve does seal well.

Another possibility is to freeze the line, but it doesn't seem like the best approach here.