Help Identifying plumbing part

[ordinarily_confused]

Can anyone tell me what this part is and how to use it or adjust it? I have a circulator pump on my water heater for instant hot water. There are two of these devices--one on either side of the pump. There is no water flowing through the pump after I had a new water heater installed. If these are gate valves or ball valves, I want to make sure I have them open (perhaps the plumber closed them and forgot to open them). I tried turning the screw and then also turning the hex nut. Some water dripped, but no flow. I may have a failed pump, but I still need to know how to set these devices correctly. Thank you.

 

[Cwhyu2]

yes ball valves the slot on the stem should be in line with the pipe for open.1/4 turn

 

[Sponsor]

 

[ordinarily_confused]

yes ball valves the slot on the stem should be in line with the pipe for open.1/4 turn

Thank you cwhyu2! You are correct. I opened both valves by aligning the slot to the pipe. The water is flowing through the pump again. Solved !!!