Another Plumbing Question: Why won't threaded Sharkbite thread to 1/2" brass pipe

[Tidybuoy]

I am installing an "in-wall" toilet tank. At the top of this tank is the inlet for water supply and it is a 1/2" male threaded pipe. The plastic protective cap that it came with it, screws on perfectly and so does a 1/2" pvc cap. BUT, the sharkbite female threaded connector won't thread more than a few turns. I also bought a copper threaded connector and it won't screw on more than a few turns.

I don't want to crank down on this and ruin my expensive toilet. Can anyone with knowledge help me figure this out. I'm wondering if the shark bite fitting is tapered and therefore just really tight fitting. My initial idea was to use copper plumbing but since this connection point is coming out of a plastic tank, I don't want to risk melting it.

I'm open to all suggestions but will probably bring this question to my plumbing supply store with my questions.

Thanks!

[908/930]

There are a couple different pipe threads, check the manual for the toilet and make sure it is intended for 1/2 NPT. There is also NPS (straight thread) usually with a O ring, and some others. But with NPT (Tapered) what you are describing sounds correct, the taper and some pink teflon tape is what seals the thread.

[Zeke]

You wouldn't solder the connection after it was screwed in anyway.

What 908 said. NPT threads down the length of its own size. 1/2" should take up 1/2" of male threads. Best thing to do is take that temporary cap with you.

[unclebilly]

Originally Posted by Zeke

You wouldn't solder the connection after it was screwed in anyway.

What 908 said. NPT threads down the length of its own size. 1/2" should take up 1/2" of male threads. Best thing to do is take that temporary cap with you.

Are you sure? Maybe combined box and pin... a 2" NPT thread is only about 1" long. I think a 3" is the same.

[Zeke]

^^^^Depends on the thread, of course. Maybe I was thinking of how long the threads should be. 1/2" NPT come about 3/4" threaded and the fitting goes on pretty close to 1/2. When you get up to 2" count me out. I don't play with the big stuff.

I have seen some toilet fittings that don't screw on very far on a plastic nipple. That could be the case here.

Take the cap.

[dad911]

Originally Posted by Tidybuoy

...... BUT, the sharkbite female threaded connector that I bought won't thread more than a few turns. I also bought a copper threaded connector and it won't screw on more than a few turns.......

Are you assembling dry, teflon tape, or pipe dope?

[Tidybuoy]

Originally Posted by Zeke

You wouldn't solder the connection after it was screwed in anyway.

I won't be soldering any connection that is threaded. I was referring to a copper connection piece that is threaded on one end (to attach to the toilet tank) and would need to be soldered on the other end (to attach to the water supply).

Originally Posted by dad911

Are you assembling dry, teflon tape, or pipe dope?

I haven't used any tape or dope yet. I was merely trying to see if the Sharkbite fits (dry) but it only screws on a couple of turns. I need to get this right because this will all be concealed inside the wall and I will lose access once I sheetrock.

This is the inlet port for the in-wall toilet tank:



A plastic 1/2" pvc cap screws on fine and all the way:



A Sharkbite piece will only screw on a couple of turns and is then very snug. I'm worried about tightening down with a wrench if it's going to strip threads. Or, is it supposed to be a really tight fit and will turn easier when I use dope or tape?

[Tidybuoy]

Originally Posted by 908/930

There are a couple different pipe threads, check the manual for the toilet

The installation instructions are completely worthless. All pictures and were clearly drawn by someone in China that has zero skills. I have referred to competitor's videos and instructions for installation. All brands are similar but not identical.

[dad911]

Pic worth 1000 words. Looks like a typical toilet connection, which uses a flex line to a gasketed sealed connector. Does not look tapered



Edit: Not that I would be comfortable sealing up that kind of a connector in the wall, I think you need some expert advice (not mine) for this application.

[908/930]

I think you want a 1/2 FIP to sharkbite adaptor fitting. Or FIP to PEX

[Tidybuoy]

This is a picture of a competitor's setup. My "Homary Brand" in-wall tank did not come with a supply line but only came with the port on top of the unit.

I would not buy this brand again. The only sensible install instructions came from their competitors websites. Very Frustrating!

[Baz]

I'd put a ball valve fitting on there Vern...maybe it would screw in better for you, too.

You'd also have a convenient shut off, in case you had service work to do down the road, God forbid.

SharkBite Max 1/2 Inch x 1/2 Inch Ball Valve with FNPT Connector, Push to Connect Brass Plumbing Fitting, PEX Pipe, Copper, CPVC, PE-RT, HDPE, UR22182A


$18.27 from Amazon

[1990C4S]

I think you're threading an NPT fitting onto a straight thread...

[rfuerst911sc]

I would install an access panel for future repairs .

[Tidybuoy]

Originally Posted by Baz

I'd put a ball valve fitting on there Vern...maybe it would screw in better for you, too.

Thanks. My current setup has a shutoff inside the plastic access point of the tank. However, I will do whatever I can to get this connection right. I may even have to change out the entire fitting to something that works. On the inside of the tank is a shutoff valve and then a port that connects with a very short normal flexible plumbing that you would see on a normal toilet.

The setup also came with a separate shutoff valve but no directions as to what/why this is there. I'm assuming it is an optional type of connection that is very similar to what came already installed.

I will take some photos tonight.

[Zeke]

Originally Posted by rfuerst911sc

I would install an access panel for future repairs .

One would think that the metal frame is for that purpose. No one would conceal a water supply device if they were thinking about the future. Per one distributor:

"First, most manufacturers use a button kit with an access panel, giving room for full servicing through the that space when the button kit is removed. It is a bit tight, but once you’ve done it once, you realize it is very possible. Second, if you want greater access, you can always have the back face an unused space, closet or other area where you can utilize a large access panel for full visualization. and servicing."

Another problem brought up is venting the tank.

[greglepore]

Regardless of how you solve this, I'd not install it without an access panel. Hide it behind something framed if it bugs you.

[Tidybuoy]

Some more photos:

This in-wall tank has an access panel in the front and all internals are accessible. However, the input port is supposed to have a permanent connection. I just need to find a replacement valve that will work or a connection that fits.

This is the underside of the input port. It has a shutoff valve.:


The complete input Port removed from tank:
Included was an additional valve (chrome) that goes to nothing and is possibly a replacement for the pre-installed valve. Nothing that I have screws onto the chrome valve and I am assuming it is to be used if I were in a foreign country with different sizing.



View from above with valve removed:

[Zeke]

No NPT anywhere in those pics. Early on when brands like Grohe came on the market we had a tough time with adapting to metric inlets. The female thread in the inlet was 9mm. Not the nut size.

[gregpark]

I just googled "sharkbite thread adapter" and every adapter you can imagine is available. Amazon and many other sources. I believe yours is at the top of the list