leaking PVC fitting

[albee]

I'm installing a new pool filter, and I'm connecting a male pvc pipe into the plastic/fiberglass? body of the filter (female connection). I'm using a union (I think that's the term) so that I can screw a male end into the filter separately from another female piece that I screw onto the pvc pipe. I then have a ring which attaches these two pieces. Frankly, while I thought it might come in handy, I also didn't know of any other way to attach the filter (kind of hard to turn it around the pipe, which is fixed). Anyway, the real problem is that the male end which I'm screwing into the filter leaks. I initially wrapped it 1-2 times with teflon, which I later read wasn't enough. I did three wraps now, and it leaks less, but still some. Should I do more? Or is there another thing I should be trying, such as an O ring? Or plumber's dope? Or try another union?

[albee]

Okay, in doing further research...

I've found that for 1 1/2" pipe, I should be using a heavy-duty teflon tape. But aside from that, that teflon tape isn't meant as a sealant, except for tiny deficiencies in the threading. My leak appears to be bigger than that. Don't even know if my threads are tapered in order to provide the necessary waterproof seal (just learned about that "Duh" factor!). If they aren't, though, should I then be using an O ring? And if they are, what else could be the problem? Thanks.

[Joe]

By all means, use Teflon plunbers dope. It's more of a sealant than the tape. Some newer parts may also be a good idea. HTH

Joe

[albee]

Thanks. Hopefully, I didn't damage the union. Wouldn't think so, but we'll see. It seems clear enough that it's a tapered thread, as the manual says to use teflon and hand-tighten, then one more turn with a wrench. So the only thing it should be is insufficient tape/compound. The degree of the leak surprised me, though. But then, I just saw that code/industry recommendations are that red teflon tape is required for over 1/2" diameter pipes. Mine is 1 1/2". They don't even carry red (that I could see) at Ace! Geez... I'm on my way to get some RectorSeal plumber's dope, based on recommendations elsewhere. Maybe it is enough. Thanks again for the replies.