Many folks do not understand about how the various plastic pipes are joined. There are 3 basic kinds of plastic pipe; ABS, PVC, and CPVC. They are chemically different. That much is easily understood. The problem comes in the fact that what we all commonly call pipe "glue" or "cement" is neither of these. They are solvents that melt the top surfaces of the pipe and fitting briefly. When the two surfaces are joined, the liquid surfaces combine into what is actually a chemical weld. So, it's not a matter of bonding, strength, or sticking. Each type of pipe has its own solvent, so the answer to your question is, No, you can't join different types of plastic pipes, except by using appropriate adapters. Not known what you are doing and why you would need to join CPVC to PVC, it's hard to advise you on what you may need to do. A couple of problems with PVC and CPVC pertain to why you are mixing media and size incompatibility. In other words, 3/4 PVC is not the same size as 3/4 CPVC.
Many folks do not understand about how the various plastic pipes are joined. There are 3 basic kinds of plastic pipe; ABS, PVC, and CPVC. They are chemically different. That much is easily understood. The problem comes in the fact that what we all commonly call pipe "glue" or "cement" is neither of these. They are solvents that melt the top surfaces of the pipe and fitting briefly. When the two surfaces are joined, the liquid surfaces combine into what is actually a chemical weld. So, it's not a matter of bonding, strength, or sticking. Each type of pipe has its own solvent, so the answer to your question is, No, you can't join different types of plastic pipes, except by using appropriate adapters. Not known what you are doing and why you would need to join CPVC to PVC, it's hard to advise you on what you may need to do. A couple of problems with PVC and CPVC pertain to why you are mixing media and size incompatibility. In other words, 3/4 PVC is not the same size as 3/4 CPVC.
I beg to differ... PVC and CPVC have different applications, so they are not typically used in the same types of applications. CPVC goes through an extra chlorination process, which lets it withstand high temperatures much more effectively than regular PVC. While PVC starts deteriorating at 140F, CPVC stays strong up to 200F, which makes it perfect for water supply lines. PVC, on the other hand, is most often found in drain lines since it’s cheap and doesn’t rust.
The first thing to consider is size. Are the sizing systems even compatible? All major brand PVC pipe is made to NPS (Nominal Pipe Size) standards, or “schedules.” Schedule 40 and 80 are the most common NPS schedules. The schedule determines how thick the wall of the pipe will be. The size name (given in inches) is just a nominal size, so the measurements will not be exactly that size. A 1” schedule 40 pipe, for example, will have a 1.029” ID (inside diameter) and a 1.315” OD (outside diameter). Sch. 80 PVC and sch. 80 CPVC will fit together because they have the same ID and OD. The same is true of schedule 40 PVC and CPVC, but that type of CPVC is rarely used.
One major difference between these two types of piping, when it comes to sizing, is the fact that CPVC is made in two different sizing systems:
NPS and CTS. CTS (Copper Tube Size) is, as the name suggests, the same size as copper piping. This is a source of confusion, as CTS CPVC and copper are both commonly used for the same jobs. CTS pipes and NPS pipes
are not compatible. Usually CTS CPVC is yellowish in color, while NPS CPVC is gray (sch. 80) or off-white (sch. 40). They are also marked on the outside, so telling different types of piping apart should not be difficult
Just because CPVC and PVC can fit together, this does not
necessarily mean they can actually be implemented into a working system.PVC cement (or glue) does not work like regular glue. It breaks down the surface of the pipe it is applied to and chemically bonds pipes and fittings together. For this reason, you cannot use just any PVC cement to join these two materials together. CPVC, as we explained earlier, is a stronger version of PVC pipe with a higher melting point and tougher chemical structure. This means old-fashioned PVC cement will not be fully effective on CPVC.
**So, NO; There is no special “CPVC to PVC glue,” and chemically joining CPVC and PVC requires solvent cement and primer that are strong enough to fully bond CPVC pipe. To connect PVC to a CPVC fitting (or vice versa) follow these steps:
- Brush CPVC primer on the outside of the pipe and inside of the fitting about 2 inches deep.
- Immediately apply a light layer of CPVC cement to the area that is primed outside the pipe and inside the fitting.
- Slide and twist the pieces together then hold them together firmly for 30 seconds.
...HOWEVER; interchanging the TYPES this will not pass inspection if the plumbing line REQUIRES CPVC because of line pressure or temperature, because you have to use the specification of the lesser pipe/fitting type - in this case being PVC.
Additionally, PVC and ABS can also be joined with solvent connection [
no more "rubber boots" to blow out! :|) ] ...
https://www.homedepot.com/p/Weld-On-4-oz-ABS-PVC-794-Transition-Cement-in-Green-13369/203111088
Anyway...wasn't trying to be a wise-a$$ but a lot of people don't know about the new solvents and standards for the pipe fittings... I guess inspectors finally red-tagged enough jobs that plumbers and piping companies took notice...