I would like to fix or install a new water line tap for my HVAC humidifier. When I unscrew the tap to allow water to pass to the humidifier, water drips from the tap. I have attached a picture of the water line tap. What is this type of tap called?
I corrected your link. It is called a "saddle valve"
I'm not a big fan of saddle valves for this very reason. They leak and usually cannot be turned off.
With that galvanized pipe, I'd remove as much of the galv as possible, replace it with copper, pex, or CPVC, then add a valve, then reduce it to fit the water line to the humidifier.
If the valve leaks when turned on, dripping from the stem, it may need new packing. A simple procedure if you can turn off the water. You might have to shut off the main valve.
Try this: Gently tighten the nut at the base of the tap.
Saddle valve has a large rubber washer that unfortunately cracks in no time causing leaks. The contractors who install them never think "long term".
I never knew you could install a saddle valve on galv. Thought they were copper to copper only. Since they have a self-cutting (piercing) needle, I guess whoever did this drilled a hole in the pipe.
If that's cap I see, remove the cap and short nipple, screw in the tight fittings to adapt to the water line for your fixture, add a ball-valve shutoff.
Saddle valves are soooo bad they are not even accepted by the Canadian plumbing code. I hate them they leak if you use them and can snap off , some times later. If I ever had to use one I would suggest to the customer that I replace it with a ball valve, if they said no then I would tell them there is no garenette
on my work as to the saddle valve.