A water valve cracked today at my house and had to call a plumber. He replaced it with a gas valve (yellow handle). He said he uses gas valves because they are better quality.

What he installed looks like this: enter image description here

I did a search based on what's written on it and it's tested up to 30 bars and seems it can be used for water also... but I'm still not 100% sure.

Where I live, the water pressure is 3-6 atm in the pipes, depending on how tall the buildings are.

Can this be used for water? Are there any disadvantages for using it for water?

  • One big disadvantage is confusion. If I saw it, I'd wonder whether anything else was "wrong". Apr 15, 2019 at 17:08
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    I'd worry about lead content this is probably known to cause cancer in the state of California. The domestic water specific shutoffs are now typically very low lead due to the California labeling requirements. Apr 15, 2019 at 17:20
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    @FreshCodemonger I just looked at one on Home Depot - sure enough, it has the California lead warning. So that may be a real code/legal issue, at least in California. Though from a practical standpoint, the amount of lead that could leach from one little valve (as opposed to large lengths of pipe) and that valve being (typically) steel or brass with a very little bit of lead, not primarily lead, is basically "so close to 0 as to be irrelevant". But better a flooded house that that little bit of lead... Apr 15, 2019 at 18:02
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    Maybe write "WATER" on the pipe or next to the valve just so everyone knows what's going on.
    – JPhi1618
    Apr 15, 2019 at 20:19

3 Answers 3


It is common/normal for valves to be rated for multiple service types.

As such, so long as it is rated/certified/locally acceptable for the type of service it is in, and rated at or above the operating service pressure of the service it's in, it's fine.

Locally, I'd be looking for a "NSF-PW" (National Sanitation Foundation - Potable Water) or one of a number of other more obscure codes indicating suitability for potable water service.

If it can also handle gas, I don't care, in water service. In gas service, I care that it can handle gas, and is suitably rated for that service, and I don't care what the water ratings (if any) are. The only place I might care about both would be my spare parts collection, where one valve could fix either type of service, if suitably rated for both.

If it makes you happier, paint the handle blue, or red, or whatever color you expect it to be.


In the US industrial valves are normally marked " W O G " , for water oil, gas. Ninety degree turn ( on- off) valves are usually called cocks. They are not very effective for throttling which is likely why they are not often used for water ( where one might want to adjust flow). I often use them in water when I want an on/off operation. One advantage is that looking at the handle you know if it is open or closed.

  • The other advantage is, they rarely ever break. The valves with screws on the top go bad over time. Apr 16, 2019 at 6:02

It could be used for water, but it is unprotected steel and will corrode. That is why water pipe and fittings are usually galvanized or made of corrosion resistant materials like copper and brass.

  • I'm going to bet on bronze here, as the OP indicates it's listed for water service, and guessing at metals from pictures alone is a relatively imperfect game. The first thing that comes up in my search on EN331 is a nickle-plated brass valve (also) made in Italy, though I can't tell if it's the same exact one.
    – Ecnerwal
    Apr 16, 2019 at 1:22
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    Ok, the wrench marks look like steel though... hard to tell from the pic really Apr 16, 2019 at 1:35
  • Indeed, hard to tell, particularly with no time for rust, if any, to form. But at least two different makers of valves meeting these certifications use a nickle-plated brass body (losing my bet on bronze) and a hard-chromium plated brass ball. Perhaps nickel plating is a different approach to keeping the lead out of the water path in water service.
    – Ecnerwal
    Apr 16, 2019 at 1:37

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