Do you know what a OS&Y really does?

[bucs1fan]

When you see a OS&Y outside of a structure is that the main water shut off? If your on a fire and command ask you to shut off water, you can't find the water meter in the ground or there is no PIV near by. Should you close the OS&Y?. I was told a OS&Y is for fire protection only, if you see one then that means they have fire protection (sprinkler or standpipes). Need a few questions answered please, thanks

[LaFireEducator]

When you see a OS&Y outside of a structure is that the main water shut off? If your on a fire and command ask you to shut off water, you can't find the water meter in the ground or there is no PIV near by. Should you close the OS&Y?. I was told a OS&Y is for fire protection only, if you see one then that means they have fire protection (sprinkler or standpipes). Need a few questions answered please, thanks

The OS & Y valve shuts off the water to the sprinkler system or a wet standpipe system. It does not shut down domestic water.

It stands for the Outside Stem & Yoke.

[FWDbuff]

Yes, an OS & Y valve is for fire protection only. Fire codes do not allow for fire protection mains to be supplied by the same main as the domestic system.

[bucs1fan]

Ok, that's what I thought but we did a walk through of a Elementary school that had a OS&Y when you entered the property. When we went through the school we found out that it didn't have sprinklers or have any standpipes. I was under the impression that there are OS&Y for domestic but colored blue instead of the normal red color. So if command ask you to shut off water cause someone busted a pipe from overhaul the OS&Y would do no good? You would have to find a water meter? Thanks for the reply's!

[GTRider245]

Ok, that's what I thought but we did a walk through of a Elementary school that had a OS&Y when you entered the property. When we went through the school we found out that it didn't have sprinklers or have any standpipes. I was under the impression that there are OS&Y for domestic but colored blue instead of the normal red color. So if command ask you to shut off water cause someone busted a pipe from overhaul the OS&Y would do no good? You would have to find a water meter? Thanks for the reply's!

If you are in a school with no sprinklers you are more than likely dealing with a structure and water system that pre dates the codes that current regulations go by.

[bucs1fan]

If you are in a school with no sprinklers you are more than likely dealing with a structure and water system that pre dates the codes that current regulations go by.

It was a built in 1997 but anyway. I guess it all depends on age, codes, location, pre-planning. Was hoping there would be a set stone rule or code on this. So what I'm getting out of all this is that OS&Y is or should be for fire protection only and a above ground or under ground meter/shutoff for the domestic water control. Controlling water sounds easy but when you need it off fast it's probably the hardest to find. Thanks for the input fellas.

[DeputyMarshal]

An OS&Y is a type of indicating valve. No mote; no less. Sprinkler systems and other fire protection systems generally require indicating valves. That doesn't mean that every indicating valve you run across is part of a fire suppression systems. No valve should ever be operated by fire service personnel unless they know exactly what it controls.

[fire49]

An OS&Y is a type of indicating valve. No mote; no less. Sprinkler systems and other fire protection systems generally require indicating valves. That doesn't mean that every indicating valve you run across is part of a fire suppression systems. No valve should ever be operated by fire service personnel unless they know exactly what it controls.

Agree os&y can be used in many settings.

And a fire sprinkler system may have different styles of shut off valves

And may be inside or out

[bucs1fan]

An OS&Y is a type of indicating valve. No mote; no less. Sprinkler systems and other fire protection systems generally require indicating valves. That doesn't mean that every indicating valve you run across is part of a fire suppression systems. No valve should ever be operated by fire service personnel unless they know exactly what it controls.

Ok that makes more sense and thanks for the info. Just to clear up, you should never close a OS&Y to shut off water? Unless command tells you to? Another question, if you have a OS&Y that doen't mean that's the only way to turn off water. There should be another turn off valve somewhere in the area.

[LaFireEducator]

If you have a sprinkler and/or wet standpipe system, it's more than likely that the OS & Y valve controls the flow to the system. In that case there will always be another shutoff for deomestic water, as another poster has mentioned, the sprinkler and domestic water supplies cannot by code come off the same line.

If there is no sprinkler or wet standpipe system, and there is an OS & Y valve, that likely is the domestic water supply.For most businesses, you will not find an OS & Y valve for domestic water, however, if they use a large quanity, such as as some manufacturing occupancies, that may be the case.

There may be times when you want to shutdown the entire sprinkler or standpipe system, and you may use the OS & Y valve for that.

As far as shutting off the sprinkler feed or the domestic water feed, both of those are command decisions and should only be done per command.

[fire49]

Ok that makes more sense and thanks for the info. Just to clear up, you should never close a OS&Y to shut off water? Unless command tells you to? Another question, if you have a OS&Y that doen't mean that's the only way to turn off water. There should be another turn off valve somewhere in the area.

There are various ways that a system can be valved

Normal is an underground valve where the fire sprinkler main ties into the supply main, the at least one more either before it enters the building or once in the building

There is no code requirement to color the valves. Sometimes local requirements require the color

[nameless]

As others have said, the OS&Y is a type of valve. It is not exclusive to fire protection uses. You'll be able to tell what it is, but being able to recognize fire protection systems and the piping involved.

[don120]

Was the valve open or closed when you saw it...?