How to Transition from Metal to PVC the RIGHT way (Beginner's Guide)

0:00If you don't connect your plastic pipe

0:02fittings to your metal pipe fittings the

0:04correct way, it's a matter of when you

0:06experience problems. Not if. Before me,

0:09I put four different common connections

0:11together and rank them from worst to

0:13best. Can you tell me which one's the

0:16best? Which one's the worst? Follow

0:17these steps and avoid these mistakes to

0:20make sure you're connecting your plastic

0:22pipe fittings to your metal pipe

0:23fittings the correct way, or else you

0:26risk having a lake in your backyard.

0:28Now, before I launch in, I know some of

0:30you out there, particularly those with

0:32some experience, are probably thinking,

0:33when you go from plastic to metal, you

0:35want a male plastic and a female metal.

0:37Now, this is absolutely true, but

0:39there's actually a lot more going on.

0:41And I'm going to share with you some

0:43information and tips and tricks to help

0:45you prevent irrigation tragedy when you

0:47go from your plastic to your metal. The

0:49worst example out of all four of them is

0:52this one by far. Here we have a brass

0:55metal male wrapped with thread seal tape

0:57joined to a plastic female. Now when you

1:00have a metal male going to a plastic

1:02female, the odds of cracking or breaking

1:04the female connection are pretty high.

1:07This is due to a variety of reasons from

1:09the different thermal expansion and

1:10contraction rates between metal and

1:13plastic to the difference between

1:14compressive and tensile strength. The

1:17thread seal tape on here makes matters

1:19even worse. Thread seal tape is a

1:21lubricant and it makes it much easier to

1:23overtighten. Now, even when you're going

1:25from a plastic male to a plastic female,

1:27overtightening is a big risk to the

1:29plastic female. So, it's even worse on a

1:31metalto plastic connection. In addition

1:34to making it lubricated and easier to

1:36overtighten, the thread seal tape also

1:39adds additional mass. Sure, it's

1:41minimal, but it's not zero. And this

1:43additional mass causes higher hoop

1:45stress, again, making it easier to break

1:48your female fitting. This type of

1:49connection with a metal male brass to a

1:51plastic female can be kind of improved

1:53by going without thread seal tape.

1:55However, you're always going to need

1:57something to seal the threads when

1:58you're going from metal to plastic

2:00because the metal is not nearly as

2:02ductile as the plastic. In cases like

2:04that where you absolutely have to use it

2:06temporarily, I hope you can use liquid

2:08thread sealant to achieve the same thing

2:10as it fills in the spaces between the

2:12threads to create a seal and doesn't

2:14increase the mask as thread seal tape

2:16does. If you do use thread sealant, you

2:18got to make sure it's a type that is

2:20okay to use with PVC. In addition to

2:22making sure it's plastic safe, you've

2:24also got to make sure it's the non-h

2:26hardening or when you go to remove this

2:28to put in something better that you'll

2:29see coming up in later on in the video,

2:30you're not going to be able to get it

2:32apart. Also, be sure to avoid

2:33overlication of sealant or tape past the

2:36last thread of the fitting. Sealant and

2:38tape can get in the flow path and cause

2:40clogs in your sprinklers or emitters.

2:42So, what's my verdict on this? Never

2:44ever do this unless you are immediately

2:46going to the hardware store to get the

2:49correct parts to replace this. There is

2:51one exception to the rule of never

2:53putting a metal male into a plastic

2:55female. And we have it right here. Here

2:58you can see we have a metal male going

3:00into a plastic female. But what is this?

3:02It has a stainless steel collar wrapping

3:04it around that gives it extra

3:06reinforcement. I prefer to use these

3:08only in temporary applications because

3:10even though it's not as much impending

3:12doom as some of the other connections,

3:14it's still not best practice. But it'll

3:17get the job done and the steel

3:19reinforced collar will help hold things

3:21together. And I have a quick tip. If you

3:23need to do a metal male to a plastic

3:24female and you don't have a coupling

3:26with a reinforced collar, you can

3:28quickly make one with just a couple hose

3:30clamps. Put the hose clamps around the

3:32coupling to secure it in place and you

3:34basically have the same effect as a

3:35fitting with an integrated stainless

3:37steel reinforced collar. The verdict on

3:39this one, it's probably not best

3:41practice, but the reinforced collar does

3:43allow you to do this. So, what do you do

3:45when you have a metal male sticking out

3:47of your wall and you don't want to use

3:48this as your permanent solution?

3:50Eventually, you're going to need to get

3:52a metal female to female because it's

3:54generally considered best practice to go

3:56from a plastic male to a metal female.

3:58However, you'll see here we have two

4:01fittings left and both of them are

4:03plastic male to metal female. However,

4:06only one of them is best practice. We're

4:09almost there. This one seems to tick all

4:12the boxes, doesn't it? We've got our

4:14plastic male carefully wrapped in thread

4:16seal tape and our metal female. But

4:18what's wrong with this one? Well, it's

4:20because it's the kind of adapter it is.

4:22It's a male pipe thread by socket

4:24adapter. And this part right here where

4:27it adapts over from male threads to a

4:29socket is a major point of potential

4:32failure. Throughout the years, I've seen

4:34many of these sheer snap and crack just

4:37from normal settling or minor movements

4:39of the earth that you can't avoid.

4:41Eventually, you're going to want to get

4:42something like a metal female pipe

4:44thread coupling that has female threads

4:45on both sides or even a brass ball valve

4:48that has female threads on both sides.

4:50Verdict, huh? Yeah, this one's not too

4:52bad and I would probably comfortably use

4:55it, but I would want to remember where

4:56it's buried just in case this part ever

4:58broke. And that brings us to number one.

5:01But what makes this number one? What

5:02makes this the way you should go from

5:04plastic to metal every single time? Just

5:07like the other, we have our male plastic

5:09threads carefully wrapped in thread seal

5:11tape going into metal female. But there

5:14is a key difference. This is a schedule

5:1680 male nipple and it has significantly

5:20thicker walls than the white PVC

5:23adapter. This one can handle some

5:25serious amounts of stress, settling, and

5:28movement of the earth and is much less

5:30likely to break at any time than any of

5:33the other options. Verdict, this is how

5:36you do it. After this nipple, you'll

5:39just add a slip coupling to this other

5:41end, and then you're good to go

5:43assembling the rest of your PVC pipe.

5:45There's one more thing you should know.

5:46Today, we talked an awful lot about

5:48using Teflon tape, what you need to do

5:49with threaded connections, but it's easy

5:51to make mistakes when using Teflon tape.

5:53If you would like to learn all the ins

5:54and outs of using Teflon tape, check out

5:56our video right there.