Long waste pipe

[sharpspark]

I wish to run a waste pipe from a washing machine to the stack which is 5.7m away, with 2 elbows on the way. The limit is normally 3m but if I use an anti syphon unit at the washing machine end and 50mm pipe, can I take this up to 5.7m?
The next problem is the height of the waste at the washing machine after climbing from the stack, as the kitchen floor is below the outside ground level. I can see the top of the brown drain bend at the bottom of the stack and have estimated the point on the stack which will be 450mm above the invert of the drain - path removal will be required to get a true fix. Following this back to the washing machine on a 1deg slope only leaves a 220mm vertical pipe to hook the washing machine waste into, measured from the centre line of the waste. Is this big enough? This is a two story house, can the 450mm above invert be reduced? (I can only gain 110mm before being right on the brown pipe with the boss). So my max possible height of the vertical pipe in the trap is 330mm from waste centre line.
I would look at using a vent pipe running back from the washing machine if this helped.

 

[sharpspark]

Update - Having investigated and remeasured carefully and measured a recently aquired washing machine trap and pipe, I can do the 5.6m run if I connect to the stack 390 above the invert. Feeding into the stack above (small 2 bed cottage) is 1 toilet, 1 shower and 1 basin. Do you think this would be OK? Then it's a question of if I can do the 5.6m run in 50mm pipe with anti syphon unit or with vent pipe?
Any suggestions out there?

 

[ChrisR]

Forget the anti-sypon device they soon block with scale. Use a stand-pipe . You'll probably get away with your height-above invert. Building Control would make you get it right though. You could put a one-way valve in the pipe - but make it accessible in case it blocks

 

[sharpspark]

This is based on using a stand pipe on the washing machine trap. It comes as 440mm from the top of the pipe to the centre line of the waste outlet pipe. Do you think this could be reduced at all?

 

[sharpspark]

A plumber has said that a 5.7m run from the washing machine would be OK in 40mm waste without any anti syphon fitted although he'd recommend a slope of 1 in 40. Anyone else feel it would be OK in 40mm?