[pbr3232]

How do you rectify the idea of using tys for venting showers etc on drain line because of lack of height for drainage fittings and the idea that only drainage fitting can be used below the flood level rim for vents. Any help appreciated.

Thanks

[speedball1]

How do you rectify the idea of using tys for venting showers etc on drain line because of lack of height for drainage fittings and the idea that only drainage fitting can be used below the flood level rim for vents. Any help appreciated. Thanks

Are you asking about venting below the flood rim or are you asking about ventingunder the floor or slab
In my area you may use a TY fitting,(see image) under the slab only if you cock it up on a 45 degree angle. But if you're referring to a shower vent why not connect the shower drain to the lavatory drain and let the lavatory wet vent it> Regards, Tom

[pbr3232]

UPC 905.3 "Vents less than 6 inches above the flood level rim of the fixture shall be installed with approved drainage fittings, material and grade to the drain."

That's is what I am asking about. People use tys at a 45 degree angle say on a shower trap arm that doesn't vent at the drainage fitting or ty. But it seems in theory you would have to use a wye and 8th bend for the vent if you were venting some wheres on the trap arm before it reached the drainage fitting say a 90.

Hope that makes sense. Because that where I am confused.

Thanks a lot.

[massplumber2008]

Hi PBR3232:

You can use a TY fitting or a wye and 1/8th bend for venting on the horizontal... as long as BOTH roll above the centerline of the horizontal drain line.

What do you mean by, " People use tys at a 45 degree angle say on a shower trap arm that doesn't vent at the drainage fitting or ty"? If the vent fitting is there and it is rolled above centerline... how is it that it doesn't vent? Lost me here...


Here, people will use TY at a 45 degree angle on a shower trap arm for the vent and then end the run with the PTRAP. The TY is rolled above center allowing air to mix equally in the drain pipe allowing a self-scouring action to take place in the pipe. If fitting... whether TY or WYE 1/8th... is not rolled above centerline you end up with a more LAMINAR flow (less turbulent) and drains tend to clog.

I don't know if this is helping. Let me know...

MARK

[pbr3232]

If the code refers to the use of drainage fittings below flood level for venting how could you use a ty at a 45 when it is on its back because that wouldn't be a drainage fitting as the code states. Or what is any ones interpretation of the portion of the UPC I mentioned.

Thanks

[massplumber2008]

Hi Pbr...

All code books have multiple sections...

As you read this code you are correct to interpret as you are, however, there is also a section that shows approved fittings for changes in direction, horizontal to horizontal, or horizontal to vertical, for example. Similarly, there are approved fittings for vents to come off drain lines... TYs are simply approved here. They are an exception to a rule... see?

There are a lot of exceptions to rules...

An example is the TY coming off for a lavatory waste/vent. Here is what I consider a drain, but here I am using a TY fitting again. This is because a WYE 1/8th would not allow air to mix properly with waste from the trap... see picture below. My code book also makes this clear as an exception.

Anyway... that is my interpretation of this. Look for the APPROVED FITTINGS section... see how it works within UPC 905.3.

Let me know what you think.

MARK

[pbr3232]

What I am saying is eliminate the ty or wye on your drawing and put a 90 in its place. Then run the drain to the trap. Between the trap the 90 is the trap arm which would be below the flood level. How could you vent on the trap arm with a ty on it back when its not a drainage fitting even at a 45 degree angle if the code says drainage fittings below flood level. The code seems to state the fitting would have to be a wye and a 8th end bend if it is on its back. The idea is taking a vent on the horizontal between the trap and what would be a 90 instead of the wye or ty on the drawing.

I draw it out if I knew how.

Thanks

[massplumber2008]

Because as mentioned it is an APPROVED fitting for this application... check it out in your code book. Here, what matters is not the strict interpretation, but the fact that air will mix in the correct ratio with the waste water and create turbulent flow.

You cannot interpret the written code ONLY. You must apply all information in the waste and vent sections of the code book... that includes tables, charts and diagrams... ;)

That make sense?

[pbr3232]

My interpretation of the code stating drainage fittings below flood level is the fitting would have to be a wye and 8th for the vent. I think the code is confusing on that point because people use tys and 45s for lack of room. Can't figure out how to upload drawings only attachment. Hard to explain sometimes but I know what you are saying and appreciate your answers.

Thanks

[Milo Dolezal]

Drain fitting use different type fittings than used for vents. As correctly posted above, you will have to use - for instance - long 90 Ell below the flood level and short, vent 90 Ell, above flood level.

The reason is that in case of drain back up, sewage column rises through the vent. Once the blockage is cleared, sewage in vents pours back into the drain. Therefore, that part of the vent has to be treated as drain so the sewage drains as it would in sewer pipe. If you had vent fittings in that part of vent than sewage would remained stuck inside, clogging the vent in process.

People don't use Y and 45 for lack of room. It is way to make proper 90 degree transition in horizontal-to-horizontal drain.

[massplumber2008]

Milo said, "it is way to make proper 90 degree transition in horizontal-to-horizontal drain". I'm confident that Milo meant from horizontal drain to horizontal vent... ;)


Thanks...

[speedball1]

3232,
How many ways do you want this explained to you. You mention UPC. Milo's your guy! He lives on the West Coast and works under UPC. Mark,(Massplumber) explained it every which way. Even I understood him. LOL Ya want to talk UPC Talk to Milo or Growler.. good luck, Tom