Re: Commercial Grade Class Four
Posted by Terry Love on September 11, 1999 at 13:38:53:
In response to Re: Commercial Grade Class Four

: The TOTO Ultramax toilet is listed as commercial class four. What does this mean in terms of how it is made and how many different classifications are there in the toilet world? Is there a master plumbing website with a chart of some kind showing the different classes? Does the commercial class four designation require anything different in the way of pipes or pipe fittings than a "residential" model?

The difference between the Toto Ultraflush and the Ultimate, is the height of the overflow tube. More height means increased flow. When a water tower is place high on a hill, the pressure increases. At the low part of the hill, pressure reducers are installed, to lower the pressure to normal working pressures.

The Commercial rating of the Toto one-piece Ultramax and two-piece Drake does not preclude their use in the home. The quick flush prevents clogging associated with some of the lessor waste moving toilets. All of the toilets in Terry Love's Consumer Report on Low-Flow toilets can be used in residential settings, and have been recomended by plumbers in the field.

Ratings in the toilet industry, are somewhat varied. Some toilets are advertised as good at flushing ping pong balls, and others at flushing 2" balls. Size of trapway is nice, but not everything. Some of the old five gallon toilets would flush a 2-1/2" ball and still plug under normal use.

Important things to consider:
The force of water through the trapway.
The sweep of the trapway.
Are there rough edges that can "catch" debries?

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