brand recommendation for angle stops or chase the threads?

[Hemi345]

Good evening,

I used 1/2" x 1/2" MNPT male adapters (Sharkbite part number UAB120LFA) on the ends of the PEX-A so if I ever needed to replace the valves, I could just unscrew them from the adapters rather than have to cut the PEX and expand the pipe to install a new valve. I bought five BrassCraft 1/4 turn angle stop valves from HomeDepot (1/2 FIP x 3/8 compression, part number G2R17X C1). I used teflon tape on the threads of the adapters and installed 3 of the valves. Two of them leaked at the threads while the third didn't shut off completely . I removed the two leaking at the threads, cleaned off the teflon tape and rewrapped them (3-4 wraps). One quit leaking at the threads but the other still did. Not impressed. I removed the valves and checked the threads on the adapters and they are in excellent condition. But I noticed on the valves that leaked, there's a ridge on the threads which I'm guessing is why they don't screw smoothly onto the adapter (I'm pointing to it with a pen in the attached photo). The one that never leaked (at the threads anyway) threaded almost completely on to the adapter and doesn't have this ridge while the others only got 2 full turns before getting very hard to turn.

Anyway, is it safe to chase the threads with a tap to try to get rid of that ridge or does it serve a purpose? Or should I just buy some better quality valves? If new valves, what brand? Is Dahl any good?
The forum is acting wierd for me but I'll try to attach a couple photos.

Thanks.

 

[Breplum]

Certainly Dahl are excellent. Are you wrapping tape in correct direction? Add a dash of pipe joint compound. I''ve never had to chase threads in fifty years, nor had a leak.

 

[Sponsor]

 

[Hemi345]

Certainly Dahl are excellent. Are you wrapping tape in correct direction? Add a dash of pipe joint compound. I''ve never had to chase threads in fifty years, nor had a leak.

Yes, wrapping tape on clockwise so it doesn't bunch up when valve is installed. I've installed many PVC irrigation sprinkler systems and usually the fittings would get hand tight after 3 to 4 full turns with 2 wraps of teflon tape and never a leak in the valve boxes. I've read a few recommendations to use 3-4 wraps of teflon with indoor plumbing fixtures such as what I'm doing here and I can barely get 2 full turns of the fitting my hand without any teflon. 3 full turns is really pushing it with the teflon fearing I'm going to crack the fitting or adapter. Does about 2 turns before being hand tight sound right for joining these fittings or is something out of spec? How many additional turns with wrenches? There's no way I can bottom out the threads without breaking something.

I have a can of RectorSeal Tru-Blu thread compound that I used when I replaced my water heater (on the gas lines) that I can give a try. The data sheet says it's safe for potable water.

 

[Hemi345]

Pictures that refused to attach to my initial post:
Ridge on the threads:

 

[John Gayewski]

You aren't tightening them enough. Use tape 3 to 4wraps, then use the roll of tape to work the tape into the base of the threads. Then dope that taped threaded surface. You need two cresant wrenches. Back up the male portion and tighten the valve until you know it won't go another turn without breaking something.

 

[Hemi345]

I didn't want to wait another week to wrap up this project so I picked up a bunch of new BrassCraft multi-turn style angle stops. Even though they're multi-turn, none of these had the ridge on the threads and they appear to be better built than their 1/4 turn style (uses a rubber gasket instead of cheap plastic "valve" inside - that's why I was interested in the Dahl... they use an actual brass ball valve on their 1/4 turn). I tightened the ever lovin' pi$$ out of them after putting 3-4 wraps and some of that Tru-Blu dope. None of them leak at the threads or past the valve.

 

[CBme]

I didn't want to wait another week to wrap up this project so I picked up a bunch of new BrassCraft multi-turn style angle stops. Even though they're multi-turn, none of these had the ridge on the threads and they appear to be better built than their 1/4 turn style (uses a rubber gasket instead of cheap plastic "valve" inside - that's why I was interested in the Dahl... they use an actual brass ball valve on their 1/4 turn). I tightened the ever lovin' pi$$ out of them after putting 3-4 wraps and some of that Tru-Blu dope. None of them leak at the threads or past the valve.

For future reference, the Brasscraft you want to find are the KT, not the G2 but that isn't available in big box store. Even the G2 shouldn't have had an issue, but it is their lower quality model. I went with Dahl which is another brand that most plumbers seem to associate with the best quality stops. I got them from supplyhouse.com