Fixture Count for Low Flow Toilt fixtures

[texanman]

What would be the fixture count for these new high efficiency toilt fixtures. I have 1.3 gpf Water closets and 1 pint urinals in a public building. Need to size the swere lines but not sure if the old fixture counts would lead to larger than needed pipes.
thanks,

 

[PEDARRIN2]

You still have to size them based upon the particular plumbing code and the fixture units ascribed to them.

But there is nothing to say you have to use a 4" for the toilets. I have started to use 3" for the lower flow toilets to help with drain line carry.

The manufacturer even suggested it.

 

[ChrisConley]

Which manufacturer suggested the 3" drain Pedarrin? That is something we'd been tossing around as an idea for a while in the office.

 

[PEDARRIN2]

It was Zurn.

We had a project where the owner wanted to go Leed Platinum and to do our part for water conservation, we specified a Zurn pressure assist toilet that flushes 1.0 gpf. I call it our "spit" toilet, because that is about all it puts out.

I wasn't about to put a 4" pipe on that thing.

In talking to the Zurn rep, he recommended 3" pipe on anything less than 1.6 gpf.

The codes have gotten a bit easier. It used to require 4" on anything that had more than 3 toilets. They took that part out so we seriously consider it in our designs.

We also put a cleanout fairly close - even if not required by code. 3" pipe is better than 4" for these low flows, but it still is not very much water going down the pipe.