name this valve(?)

[Jonathan Ewald]

Hello all! Amateur question:

What are these?

I have a boiler heating system, and these are at the front end of two of my heating water loops. It looks like a brass valve, but there's no handle. As you can see, there is a screwdriver-turned bolt. Is this correct? Or is the nuts-looking part the part to turn?

The house was built (and presumably, so was the heating system) in 2001.

I want to know what this is before I start messing with them. Are they pressure valves?Ball valves? Some other kind of turn-off valve?

What are these used for? Are they specific to a boiler heating system?

Nobody at a Home Depot has ever seen these things before.

Thank you very much in advance.

 

[voletl]

They are used for isolating a Zone when purging air out of your boiler system just a simple valve quarter turn left or right stops the flow

 

[Jonathan Ewald]

Thank you very much for your quick (!!!) response! I assume that the flow is with the line ie if the screwdriver line is perpendicular to the pipe, the pipe is blocked.

Thanks again!

They are used for isolating a Zone when purging air out of your boiler system just a simple valve quarter turn left or right stops the flow

 

[voletl]

You are correct

 

[anticlmatic]

Are those coin valves? How has nobody at Home Depot seen them? Most hot water heater drains use that style of valve.