That looks like half inch FPT to me. You would measure the inside diameter not the outside diameter. FPT means female pipe thread. You would put a male pipe thread into…..,,,,,Well you know.
What's the number above 304 on the valve body? Looks like it says 1/2 but I can't quite tell.
The inside diameter of the male piece is 1/2".
The inside diameter of the tubing itself (approximately). Then there is the tubing thickness. You could then cut threads with a die at the tubing end to make a male end to which you could screw on a female fitting. So it's helpful when it is stamped but not always the case!
Something like Blue Monster or a special "food grade" pipe dope? I can imagine some dope may get in contact with the wort, squeezing out on the inside while threading.
I think you meant to write this:
I thought “A “ had female threads. Maybe that’s the wrong one. one has a male thread to screw into, one has a female thread to screw onto- like a plate chiller or nipple
With the fitting side facing toward you (threads facing away) tape goes on counter-clockwise.
It's worked very well for my 28 years of brewing. It's easy, cheap and I don't have to worry about cleanliness(whethter it's a real issue or not is irrelevent).
I have always been worried about how clean these types of connections are. We now are only really concerned about the cold side once the wort is chilled. We sanitize everything with hot water from our HLT while we are brewing. As a minimum we pass 180 Degree F water through the plate chiller and the hose to the fermentor for at least 45 minutes. Many times it is longer. We don't worry to much on the hot side although we do clean everything (in place normally) after we brew, but just let air dry for the next brew. We have a permanent manifold that we rarely take apart. We do occasionally inspect it but have never found any issues. The cold side (plate chiller onward) we do extra cleaning and pass starsan then let dry. We then sanitize while boiling.
I have a 3 tiered pump fed system with an immersion chiller to get the temp down under 100F, and then a copper coil in an ice bath to do the final chill. The pump is to recirculate through the kettle, and eventually to the fermenter. So everything that's on the hot side eventually is on the cool side. I use one hose to transfer from the hot liquor tank into the mash tun, then that hose goes from the mash tun to the kettle, so pulling it off a barb is the simplest solution. At the end of the brewing session I pump 4-5 gallons of boiling water through the entire tubing system to clean it, and recirculating at 200F takes care of any lingering infectables(?).
