Soil pipe crossover

[garethpuk]

Hi,

I've got a leaky cast iron soil pipe (corroded) and I'm looking at replacing it with plastic, whilst flicking through the building regs I came across the guidance to prevent crossover by staggering the inlets. However its possible to buy a branch to connect a toilet with 3 blanked off 40mm pipe inlets - surely if you connect any of these to a 40mm pipe it would create a crossover? Or am I missing something?

 

[cider]

the blanked inlets to the branch will be on the same level as the branch so water wont flow into them.
Cross over is almost impossible to achieve as you wont be able to fit a connection to the branch in the wrong place if that makes sence