Connect PVC to Cast Iron

[LazyPup]

I looked at the reinforcers and I agree they look like they would do the job, however, no matter what claims a manufacturer makes about their products we may not use them unless they are currently adopted as suitable by the local code authority.

You can walk through the plumbing department of any hardware store and see dozens of products that are in common use but they are not code approved...by example,,

Female Threaded PVC fittings are common in all hardware stores, and while they are approved for some applications in heating and AC they are strictly prohibited by the plumbing codes. The same is true of compression type PEX fittings, they are approved for hydronic heating but prohibited in potable water distribution. Offset closet flanges are also prohibited but it doesnt seem to slow the sale of them.

[kactuskid]

I agree with you totally. I am surprized that items that are not leagal to use are even sold, seems like that wouldn't be allowed. But, they also sell fireworks about a mile from here, yet they're not leagal to use within at least a 200 mile radius. Wierd.

[mrcaptainbob]

For my own education....why are female threaded PVC fittings not allowed in plumbing? Would that include the male threaded as well? In other words, NO threaded PVC connectors? Are they not as physically strong? As for the PEX, what form of connection is available for use with potable water? The connectors on the whole house filters are of the same compression fitting style and material...They are the same as what I used for the 1" PEX for the hydronic system.

[LazyPup]

Everyone is familiar with the requirement in the Electrical Trade that in addition to installing the equipment per National Electrical Code (NEC) Standards, the equipment and devices must all have UL (Underwriters Laboratories) approval.

In the Plumbing trade the codes also governs the installation, but in addition to the code we have a number of testing agencies that must certify the materials.

ASTM- American Society of Testing Materials
ASSE- American Society of Sanitary Engineers
ANSI- American National Standards Institute
Mil-Spec standards

ICC International Code Council
(ICC now includes the ICBO-International Conferance of Building Officials & SBCCA-Southern Builders Code Congress International)
IAMPO international Association of Plumbing and Mechanical Officials

NFPA National Fire Protection Association

All electrically operated plumbing devices must also carry a UL label.





Female threaded PVC fittings are specifically listed in the code as a prohibited fitting...Female PVC fittings have an extremely high sidewall failure rate due to the thermal expansion of Male metal fittings. When making a threaded transition from PVC to metal the proper method is to use a Male PVC fitting, which would fit inside a metal Female fitting, thus the metal reinforces the joint rather than stresses it.

The specific code reference is:
"No Female threaded PVC fittings" International Residential Code 2904.16.2 and Uniform Plumbing Code 606.2.2.

In addition, PVC is approved for Supply piping which is the underground service from the curb box to the main water shutoff or from a well to the main water shutoff, but PVC is not permitted for Distribution piping within the structure.

The PEX compression fittings have been approved by the ASTM (American Society of Testing Materials) for use on hydronic heating systems, which are typically low pressure systems, but they will not meet the pressure standards for potable water distribution. ASTM standards require crimp on fittings for water distribution, and only if set with ASTM certified crimping tools. Pex tubing must be installed in accordance with ASTM standard F787/F788 for potable water distribution.

[mrcaptainbob]

I knew it! Not the info, but that you'd share it! Thanks, LazyPup, for coming through again. So I take it (about the threaded PVC) that it's okay to use PVC threaded to threaded, but not to use the female over the metal due to different expansion rates. Yep, as another poster say's about you and the other knowledgable ones here, there's a lot to know and understand. Thanks for being one of 'them' that keeps those of 'us' on the straight and narrow.

[LazyPup]

you may not use PVC threaded to threaded either,,,,the code says,,,NO Female Threaded PVC fittings....


In regards to why they sell products in the hardware or home supply stores that are not code approved. We must remember that many of the products used in plumbing are also used in other trades and services.

By example, while we commonly think of copper pipe as a potable water supply pipe, it is also used in both steam and hydronic heating.

PVC is commonly used in irrigation piping and in many light industrial or agricultural applications for the distribution of chemicals or acids.

In turn, the hardware retailer must stock an inventory to meet the needs of all his customers.

It is the responsibility of the installer to know what products and materials are code approved for the type of service they intend to use them for.

[md2lgyk]

I think this whole toilet-moving exercise is turning into more than I care to attempt, considering this is only operable toilet in the house. I've already decided if it would require notching a joist I'm just not going to do it. Auxiliary venting won't be an issue - I'm only planning to move the toilet a foot or so and the current waste arm is only about 4 feet long. What I fear now is that a PVC closet bend may be dimensionally different enough from the cast iron that I won't end up with proper slope or, worse yet, a reverse slope. Any advice for that possibility?

[LazyPup]

unless you have a very unusual cast iron closet bend the radius curve and fitting allowance for PVC should be the same as the cast iron so that won't be a problem.

[md2lgyk]

Excellent, thanks. As things DIY go, I'm way more experienced with electricity and carpentry than plumbing. I do appreciate all the help. I'll advise how this project goes.

[LazyPup]

Basically there is only four key things one must know to do plumbing...

Hots on the left

Colds on the right,,,

The stinky stuff don't go uphill...

and don't bite your fingernails