Are plastic water valves serviceable?

[M.Burns]

Have a rental property that had most of it's basement plumbing done with white plastic pipe and fittings. One valve with a standard red circular shut-off appears to be leaking past the valve stem and dripping. At the base of the stem in the valve body there appears to be a hex shaped top, but I can't telll if it is really designed to be opened, or if the valve is just cast that way for "looks". Would like to repack it if possible since it is in a tight space with glued couplings only 1/1/2" away on both sides (would not be fun to cut it out and try to refit and reqlue in a new valve/piping/or couplings) M.B.

[tom]

If I'm following you correctly, I call the part you think is leaking a packing nut. Try tightening it just a little bit. Shouldn't take much. Tom

[M.Burns]

Yes, the packing nut is what I was referring to (sorry the correct name escaped me). I'll try to see if it can be slightly tightened while trying to hold the vavle body itself in place. Don't like putting any type of force at all on anything plastic, if you know what I mean. I wasn't sure if the packing nut was even tightenable, or if the whole valve was somehow cast as one piece and the packing nut is not even functional. M.B.

[tom]

M.B. wrote: Don't like putting any type of force at all on anything plastic, if you know what I mean. Yes, I do. Unfortunately, the maxim "If it breaks, it probably needed fixing anyway" seems to apply here! G'luck. Tom