[Deck]

I am preparing to replace a section of extra heavy cast iron pipe that is cracked and goes into a bend that has a bottom that rusted away. I would like to know about the importance of slope. The bend looks unusual to me. It seems to be a 60 degree street going into a 45 degree street in a way that the horizontal run of pipe turns 90 degrees. The combination of the two bends to make the turn results in a slope that's probably a little less than 45 degrees since the 45 is somewhat tilted.

To replace the turn I have come down to two choices. Replicate what's there now or use two 45 degree streets (or a 90 long sweep) and a 22. The way it would work is the two 45s would act like a long 90 sweep and tilt slightly into the 22. So there would still be some slope at the turn but less than before at 22 degrees. It seems like it would be better to do that, but does it break code in NY to use that many fittings? How about the slope?

I checked NY state plumbing code but I couldn't find out the maximum pipe slope. I found this though which says 1/2" max:
Maximum slope of drain line? - InterNACHI Inspection Forum

Also does anyone know why it is hard to find really wide radius 90 degree sweeps for schedule 40/dwv PVC. Like the guy in this question I noticed at Home Depot that the long sweep wye is so much longer than a long sweep 90 and seems to have a wider radius as well. Though someone says in that question the long sweep 90 has a longer radius. Still, I compared them at Home Depot and the wye looks much longer.

Here is a pic of the section of pipe I will be replacing (after properly strapping of course) and a closeup of the bend.

 

[TheEplumber]

If I were to rebuild that and trying to match existing elevations- I'd probably go with a 90 in the horizontal section rolled down with a 22 to meet the lower pipe. whether you use streets or not would depend on your elevations.

I was taught to have the 90 be the upper fitting when possible as it's more flow restrictive than 45 or 22- I would rather flow out of a 90 than into it.

If you want to replicate what is there- that's fine too. It's just a little tougher to get alignment when fitting together because the angles are odd.

When dealing with plastic you have 2 types of 90's for drainage- regular and long turn. Most jurisdictions want long turns when turning hor. to hor. and vertical to horizontal(base of stacks). 2 45's is considered equivalent to a long turn

Regular 90's are used for horizontal to vertical and toilet stubs.

A combo is only longer because it matches the pattern of a wye and 45 glued together.

Now, if you get into cast iron fittings- the language is different. For example- whats in your picture is called a 1/8 bend and a 1/16 bend.....(with a lot of bad aids)

 

[Ghostmaker]

After you cut the cast iron hub out make sure you grind off the welded seam so it is smooth. You will also have to use a transitional coupling CI to PL on both reconnects at each end. Also since we cannot see what you have farther upstream I would make real sure you have a strong enough support system in place on the cast iron prior to making your first cut. Be very careful even skilled plumbers can lose a finger when something go's wrong because of the weight of the cast iron itself.

 

[gregzoll]

Personally I would rip out all of that old Cast and replace it with CPVC piping. Looks like too many bandaids on it.

I do like the Zip Ties. Normally we use Marlin wrapped around a patch.

This is how we were taught for DC repairs. Not one has failed yet. http://www.dcfpnavymil.org/Stations/Indexes/sec14/softpatch/PP Tip_009_Soft_Patch_(final)16Jul13.pdf

 

[Deck]

If I were to rebuild that and trying to match existing elevations- I'd probably go with a 90 in the horizontal section rolled down with a 22 to meet the lower pipe. whether you use streets or not would depend on your elevations.

I was taught to have the 90 be the upper fitting when possible as it's more flow restrictive than 45 or 22- I would rather flow out of a 90 than into it.

If you want to replicate what is there- that's fine too. It's just a little tougher to get alignment when fitting together because the angles are odd.

Thanks for all the information but I don't understand why a 90 long sweep would have more restrictive flow? What I thought I was going for here is less restrictive by having a turn with a wider radius, that's why I thought it would be better than the 45 and 60. I read that the solids and liquids can separate in waste and that's why they only allow slope that's like less than 1/2" unless you're transitioning to vertical, so I thought less of a slope would be better.

And you're right about that 45 and 60, getting that to have a turn of 90 is very difficult it's like there's only a single way to do it and for all I know the elevation may not be exactly the same.

After you cut the cast iron hub out make sure you grind off the welded seam so it is smooth. You will also have to use a transitional coupling CI to PL on both reconnects at each end. Also since we cannot see what you have farther upstream I would make real sure you have a strong enough support system in place on the cast iron prior to making your first cut. Be very careful even skilled plumbers can lose a finger when something go's wrong because of the weight of the cast iron itself.

Thanks. The coupling I have is 'Everflow 15400CS 4" Heavy Duty, Husky Type, No-Hub Coupling With Colored Shield' from amazon, it does not say transitional, it says no-hub coupling. Will that be a problem you think? Here's a pic:

The strapping I'm going to buy is 20 gauge galvanized from zoro. Here's a pic:

Personally I would rip out all of that old Cast and replace it with CPVC piping. Looks like too many bandaids on it.

The section I'm replacing is the section with all the bandaids. The pipe is disintegrating in that area for some reason. Why would you do it with CPVC instead of PVC? I thought the former was only for high temp water and this is waste line so I don't have to worry about that (I don't think).

 

[gregzoll]

Actually all of it is failing. It rusts from the inside out. Once you touch one section the next one will fail.

Go along with a Screw driver and tap the pipe with the handle.

 

[TheEplumber]

You are over thinking the angles and grade on the pipe.
LT 90 is code compliant and standard practice for decades. My code says a cleanout is needed after 135*- that's a 45 +90. If blockage was an issue, they'd ask for a cleanout at every 90.

Ideal grade on a drain is 1/4". Avoid more or less although 1/8 inch is allowed in certain situations. More than 1/4" and there is an issue of solids and liquid separation.
Rolling fittings at angles you show has nothing to do with the pipe grade.

And yes, CPVC is water pipe- not DWV. But Greg is correct on his opinion of your CI pipe. Check all of it. At worst- replace all the horizontal lines.

You want a coupling that specifically says PLas x CI. The two types of pipe have different O.D. A no-hub coupling will pucker on the CI side when tightened and not seal.
http://pascospecialty.com/flyers/proseal_couplings.pdf

 

[gregzoll]

http://pvcpipesupplies.com/cpvc-vs-pvc

 

[gregzoll]

http://www.diffen.com/difference/ABS_vs_PVC

 

[Ghostmaker]

Thanks. The coupling I have is 'Everflow 15400CS 4" Heavy Duty, Husky Type, No-Hub Coupling With Colored Shield' from amazon, it does not say transitional, it says no-hub coupling. Will that be a problem you think?

That's a great coupling if your replacing with cast iron. But if your using plastic and cast iron you need a pro-flex transitional coupling. Our Mission brand transitional coupling. There is a size difference between the different pipes the transitional couplings take that into effect.
http://www.supplyhouse.com/Fernco-3...vy-Cast-Iron?gclid=CPOk07z37swCFZWMaQod6WQMWA


http://www.amazon.com/Mission-Rubber-300044-Band-Seal-Extra-Heavy-Cast-Iron/dp/B005I02KAA

 

[Deck]

That's a great coupling if your replacing with cast iron. But if your using plastic and cast iron you need a pro-flex transitional coupling. Our Mission brand transitional coupling. There is a size difference between the different pipes the transitional couplings take that into effect.

Thanks, I looked into Proflex. However I should clarify my cast iron pipe is extra heavy (XH) so its OD is the same as PVC. I checked and it's exactly the same, the OD is a hair's width over 4 1/2 inches.

I tested the Everflow no hub coupling on the PVC and it was difficult to get on, required quite a bit of stretch. I assume that's because it must be designed for service weight cast iron which has a slightly smaller OD. I can't find out if it would be acceptable to use in my circumstances under code for NY. I wrote the company several days ago to ask about specifications and I never heard back.

The ProFlex I would need is 3005-44 which is XH CI / PVC to XH CI / PVC. Home Depot sells P3005-44 which is a Fernco but the PlumbQuik brand, and otherwise they appear to be the same. I'm thinking about getting that. I wonder if there's a code difference because the brand is different. I would prefer the extra length with the 4 clamps like the one I have now, but I can't find anything like that for XH CI / PVC to XH CI / PVC.

 

[gregzoll]

All Cast Iron is heavy. That is why they take it down with two people and chain cut it in sections as they take it down.

 

[Deck]

Yeah but what I mean is the cast iron is a specific type marked on its hubs with XH for extra heavy and is slightly larger in OD than service weight cast iron. Though I picked up some of the service weight cast iron fittings at home depot and I'd agree they're all heavy.

 

[Ghostmaker]

His cast iron is the real old school stuff. No longer made.

 

[gregzoll]

His cast iron is the real old school stuff. No longer made.

Just like the stuff in my house. This is when you ask one of the local school coaches to send you the football or wrestling team to help take it down.

 

[Deck]

For anyone following this I recently did a dry fitting of the PVC where I hanged it off the existing pipe. I used the same sized spacer on each end and then at the bend I adjusted until I had a 1/4" slope on both horizontal runs. Here's a pic:

 

[Deck]

I worked on this over the summer but I didn't get around to updating everyone. I installed the PVC and I'm almost done except for some bracing. Here's what's happened since I last wrote:

I cut the bad pipe into pieces using an angle grinder with a 1/16" metal cut off disc. I went through like 7 discs (I also cut up some vent piping). It was really messy, there was dust everywhere and I came close to getting little bits of metal in my eye even with a face shield and face-conforming safety googles. A few times my eye was irritated but luckily it cleared up. I would guess the dust got in through the google vents, there was just so much of it.

Here's a picture of the temporary strapping I used to hold the pipe so the pieces wouldn't fall to the ground:

I had read somewhere that you could use a chisel and slowly tap around the diameter of the pipe and it would break eventually. Well, I tried that and it never did. After a full cut at each end with the grinder to free the bad section I tried working it with a mini-sledge. That worked sometimes, if I cut at least half way through and hit it a bunch. So mostly I used the grinder wheel to do whole cuts.

Next I melted the lead out of the cast iron hubs using MAPP gas. Wow was that a huge pain in the ass, likely very dangerous and it took a very long time but it did work. Then I used a wire wheel to clean the hub. Unfortunately I do not have any pictures of this step. If anyone is reading this I would stay away from this at all costs. I had an existing house trap with a hub and the pipe going into that hub was cracked on its way in so I couldn't just cut the pipe at some earlier point.

The hubs had an unusual ID of 5.25" (Cast Iron XH Somerville? I think) and the Fernco 44UX-405 donut was too small, according to Fernco. They ended up sending me a lipless donut Fernco D428-405. But for extra protection I got a second multi-tite XH serco donut V94004 and basically did a double gasket on the horizontal hub. (The vertical one I just used the serco.) The double gasket involved cutting a 1/4" off the fernco and putting it in all the way first. With these two donuts there is no sitting water in the hub since the double donut fills the entire depth. Here's a pic:

Next I had to insert PVC in the gasketed hub. Also another thing I don't recommend. I actually pulled PVC from a different gasket and found the PVC had bent in shape over time (just several days) because of the pressure the gasket put on it. If I had to do it again I would have taken a short piece of cast iron pipe and put it in the gasket then used a transition coupling to PVC.

That cast-iron to PVC may also be code, NYS code on sanitary drainage says:

705.18.4 ... Joints between plastic pipe and cast-iron hub pipe shall be made by a caulked joint or a mechanical compression joint.

Anyway... here's a pic of inserting the PVC. I beveled the pipe and used duck butter for lube and some chain clamps to really force it in.

And here's what it looks like now that it's installed. The pipe that goes up and to the right is the vent for the house trap.

So now I just have to add some more pipe supports. PVC support spacing is a maximum of 4ft according to NYS code on pipe supports. Also it requires sway bracing at turns, which I've never seen and sounds expensive:

308.6 Sway bracing.
Rigid support sway bracing shall be provided at changes in direction greater than 45 degrees (0.79 rad) for pipe sizes 4 inches (102 mm) and larger.

Anyone a plumber in NY or had to use sway bracing on 4" PVC?