Plumbing sink waste into SIDE of soil pipe

[tweakyboy]

Ok, yes that does make sense. Thanks for your reply 

does the hepvo fit in addition to the trap?

also will I still need a no siphoning trap with the hepvo valve?

Oh yes I have a landrover too lol

The HepVo valve is a trap which allows air in when it is needed. So it will be anti siphoning but there is no water in the trap to siphon out!

 

[stratplus]

What's a non- return valve on waste pipe? Do you mean a hepvo ?

 

[Amondeggs]

The HepVo valve is a trap which allows air in when it is needed. So it will be anti siphoning but there is no water in the trap to siphon out!

ok, that sounds brilliant, thanks

so I will fit hepvo under sink,
replace push fit with glued joints,
And change to swept elelbows

job done,

thanks to all that have helped me , really appreciate it