Are Long sweep fittings required after P-trap

[Freddiy]

I'm installing two new sinks in my basement and was wondering if I need to use long sweep fittings after the p-trap since they are tying into a horizontal drain in the wall. My reason for asking is that my plumbing book says that a long sweep fitting is required for all horizontal transitions. However these fittings don't lend themselves well to coming out of the wall neatly to tie the p-trap into. Are they really require in this instance or can I use a regular 90 degree fittings?

Thanks Fred

[pushkins]

I don't see why you cannot use standard 90 degree elbows, I don't think the code demands it on 1 1/2" waste lines. If the vanities are side by side and the waste line is horizontal behind the vanities one of the elbows will need to be a "whye"

[HayZee518]

horizontal waste lines can't be "horizontal" they must pitch 1/4 inch per foot. any connection into a horizontal run should be cut in with a tee-wye and an eighth bend. look at some of lazypup's plumbing drawings.

[Redwood]

Freddiy, How is this line vented?

[596]

Fittings on the waste line must be "drainage" fittings, meaning long sweeps on ells.

[jnaas2]

[jnaas2]

Sorry the picture turned out so big but as you can see from the picture they used a short sweep 90 where the 1 1/2 inch pipe turns out to accept the p trap. The reason for not using short sweep 90s on horizontal pipes is that you will lose the velocty of the water flow as it turns the short sweep, but this is where the water starts and the velocity is usually high since it just dropped vertically from the sink. The tee with the other tee directly above it for the double sink is unusual, but they do make a double sanitary tee with a connection on the top for the vent line to connect into the drain

[Redwood]

Actually Jnaas2,
A double fixture fitting shown as #500 on page 30 of the Charlotte Pipe Co. PVC/ABS Dimensional Drawing Catalog linked below should be used instead of a double sani-tee.

http://www.charlottepipe.com/Documents/DimensionalCatalogs/Plastic_Pipe_Fittings.pdf

I am somewhat concerned about Freddiy's vague description of tying into a horizontal line though and I have visions of it not being anything as nice as the picture you posted. An isometric sketch of what he's doing would be very nice but even a rough sketch would be nice before we stamp an approval on the project.

[Redwood]

Fittings on the waste line must be "drainage" fittings, meaning long sweeps on ells.

So what you are saying is that a long sweep 1/4 bend such as #304 on page 19 in the Charlotte Pipe PVC/ABS Dimensional Drawing Catalog linked below must be used and not the #300 Regular pattern 1/4 bend elbow shown on Page 17. Both of which are approved drainage fittings...

Or, is it the #331 vent el shown on page 23 of the catalog that you are saying can't be used?

http://www.charlottepipe.com/Documents/DimensionalCatalogs/Plastic_Pipe_Fittings.pdf

I'm just trying to have a clear picture of what you are saying.

[Freddiy]

Thanks to all who posted replies to my question. This is a great forum to get help so quick. Here are a few answers to the follow-up questions that were posed.

• I would have posted a sketch yesterday but for some reason the system wouldn't accept my sketch. However it did today so hopefully this will add more clarity.
• You will see that I am using 2 inch pipe to allow myself the 3.5ft run between the vent and the wet bar sink.
• I'm tying this into a rough-in that the builder left in my home.
• Yes, I am aware of the 1/4 pitch for horizontal pipe runs and have that planned in.
• You can see how I am venting the system. Should be OK.
• My current plan was to use a 2" long sweep 1/4 bend on the wet bar sink connection and use a reducer to connect to a 1-1/2" P-trap. On the vanity sink I was planning a 2"x2"x1-1/2 tee-wye and an eighth bend to connect the 1-1/2" p-trap into. However standard fittings make for a nicer fit through the wall which is why I posted the question.
• As for Redwood's question I was planning on using 1/4 bend #304 vs #300.

Thanks for the help.
Fred