SpudFiles

i have used dwv fittings in a test pipe thing, i stood behind my stone wall and pressurized it at different increments. even though the dwv fittings arent rated for anything, the 2"-1" bell reducer held up to 100psi pretty well. i dont know about the pressures in between, but it blew at 130 psi, just to be safe though, go with the reccomendations and stay 30-40 psi below 100 for a good saftey margin.

Here's a more recent picture of it painted.

The red parts on the hose nozzle are also grey now though.