Are these shut offs??

[Kate327]

Are the plastic knobs supposed to turn??
Seem very stuck and not sure direction to keep trying to turn???
Thank you!!!

 

[Terry]

They look to be shutoffs compression fitted onto 1/2" copper pipe to 3/8" OD copper.
I would guess them to be multi-turn, left to open/right to close.

 

[Sponsor]

 

[Kate327]

Terry any hints to loosen them up. I tried Wd40. no difference. Almost feels like the plastic knob is going to break if I put more force on them.
Thanks again!

 

[Jadnashua]

If a valve is never opened or closed for a long time, mineral deposits can 'lock' things in place. WD40 probably won't do much. A penetrating oil might. Worst case, replace them with new.

 

[Reach4]

You may want to get the valves replaced. If you want to do that yourself, search this forum, with the search box above, for "ferrule puller" or "sleeve puller" (with the quotes).

 

[Plumber Man]

They are 1/4 turn valves which were poorly designed.
If you would get the valve to shut off there's probably a 90% chance it will start leaking at the handle.
When I go in on a service call and see one of these valves I tell the customer up front we're probably going to have to replace it.