"Fully Glazed Trapway" What does that really mean?

[JohnnyK]

I just got a Vespin II from a local supplier and when I turned the bowl over to see the part of the trapway that plugs into the unifit adapter I see that it is not glazed inside. Is this a defect that I should call Toto USA about?

I am also disappointed in the design of the unifit adapter. Why wouldn't it have been designed with a smooth turn rather than have a step molded in to the bend. Maybe there is a reason.

John

 

[Terry]

Fully glazed doesn't mean much. I find I get better performance if things are a bit rough. Wipes and such don't stock to rough surfaces. That being said, sometimes I see a lot of glaze, and sometimes it looks like nothing. It doesn't seem to matter in use.
I have the Vespin II installed in the main bath at the moment. It works very well.

I don't know how you would glaze this plastic trapway though.

https://terrylove.com/forums/index.php?threads/toto-fully-glazed-trapway.7/

 

[Sponsor]

 

[hj]

"Fully glazed trapway" is a "sales gimmick" which means very little in the real world. IF they tried to make a "smoother" turn it would not fit in the space they have available, either in height of horizontal length.

 

[Reach4]

Regarding the Unifit, I think the question JohnnyK proposes is why did the centerline not follow the yellow path rather than the blue path? I wonder if there was some need for clearance in the area with the pink oval? Or maybe it just allowed the switch from vertical to horizontal to be more gentle (left side of yellow line)?

 

[Terry]

I am a civil engineer (water, sewer, flooding, paving). At my office the landlord recently installed a Toto toilet, and I am effusive about it! I don't know which model it is, but it is amazing, and in inspecting it, I can see it has a double siphon below the bowl. The only thing I can't understand is why there aren't more double siphon toilets around, unless Toto has a patent on the double-siphon concept.

Let me explain briefly why the Toto is so simply amazing. Most toilets have a single siphon below the bowl that gets started when you dump water into the bowl (by flushing it the normal way or with a bucket) and then stops when the siphon gets broken either 1) by running out of water in the bowl and letting some air in the top (making that end-of-flush gurgle) or (and this is the catch) 2) by slowing down to the point that water dribbles away and lets air enter from the sewer and break the siphon. But Toto toilets have a second siphon near the floor that doesn't let the first siphon break until the flush is done and water runs out in the bowl. This forms what Toto calls a Power Gravity Flush. You get the vacuum effect of the entire height from the bowl down to the floor pulling the water and solids out of the bowl. Very ingenious. I've sketched it below.

Tom Haws, P.E.
HUBBARD ENGINEERING
Civil Engineers and Land Surveyors

June 1, 2006

 

[hj]

It is like an "S" curve in the road. It had to go down to the blue line in order to make the first turn, but then rise to green line to make the second one. Otherwise both turns would have been too "sharp". IF the bottom bend were REALLY a second trap, then it would be the classical double trap configuration and it would NOT flush properly. As you can see in the photo, the bottom "trap" only rises halfway so it neither makes a second trap, nor does it create a stronger vacuum.

 

[Terry]

The TOTO trapway is designed to create a stronger siphon by fooling the water being pulled into thinking it's smaller. Thus more pull. It also points the waste down the closet flange.
hj, there's a method to the madness here that works.

 

[Jadnashua]

FWIW, glazed, does not mean shiny smooth, it just means it literally has glaze on it. As Terry said, rough seems to work better because that slight roughness means water can get underneath things and peel them free. A glaze prevents stuff from seeping into the porcelain, but that in itself is pretty dense.

 

[JohnnyK]

View attachment 27478 Regarding the Unifit, I think the question JohnnyK proposes is why did the centerline not follow the yellow path rather than the blue path? I wonder if there was some need for clearance in the area with the pink oval? Or maybe it just allowed the switch from vertical to horizontal to be more gentle (left side of yellow line)?

In the unifit I was referring to the step you see when looking down through the rubber seal. This may be a case of a little turbulence being a good thing. My 14" unifit came yesterday so as soon as I get the floored laid I'll be able to install the toilet. Thanks for the info guys.

 

[Terry]

In the unifit I was referring to the step you see when looking down through the rubber seal. This may be a case of a little turbulence being a good thing. My 14" unifit came yesterday so as soon as I get the floored laid I'll be able to install the toilet. Thanks for the info guys.

The step looking down into the receiving end receives the spigot portion of the bowl exit.
It's not a problem.