Pipe thread question, not screwing in completely. Is this ok?

[MitchRyan912]

Sorry for the large image...

does led this adapter need to be screwed in further than I'm able to get it screwed in? I've used liquid Teflon on one of these and pipe seal tape on another and they won't go in all the way, like I was able to do with another one I've already installed (not pictured.)

Is the seal probably good enough on the left fitting? I'm guessing the right one is no good. Thoughts?

 

[NeedMoreSun]

If it bottoms out you would have it too tight. It should be "roughly" finger tight and then an additional 1.5 turns or so. I've seen many recommendations from 1 to 2 turns, and "finger tight" also varies per person. It takes a little practice sometimes. Using either tape or a sealant the treads are effectively lubricated and easy to over-tighten and create stress and future crack of the female adapter.

Since it goes to a barbed hose fitting though it's an easy spot to re-try if you have a drip.

 

[Bama Rambler]

Tapered pipe threads are designed to fully seal at about 3/4ths engaged. If you overnighten them it can split the female part.

 

[pabeader]

Some PVC fittings aren't tapered. I know the ones for electrical conduit aren't. You might have gotten one of those and that's why the other fittings went together farther. I use that trick to create low cost bulkhead fittings.

 

[Zomalaja]

I'm new here so not sure if URL's are ok.
Try this link at LASCO, one of the biggest manufacturers of fittings. Basically what NeedMoreSun said is exactly correct.