What kind of valves are these?
I believe it would be called a "block and bleed" cock in industry. "Cock" because it is a 90 degree turn off/on. And the B &amp; B because the small ( 1/2 " ?) knob on the lower part will open to bleed a line when the cock is closed. That of course , assumes that the supply is coming from the top pipe in the view.