Fuel hose sizes and types please?

[Slimlavud]

I have just bought a 1995 Volvo 940 S TIC auto estate (wagon), I had a 740 TD previously that had the same small problem - dribbling return hoses on the injectors. I got round this on the 740 by shortening the original (original looking) braided hoses and stopped them leaking. I would like to change some of the original (looking) hose on this 940 as one of them is leaking. What are the hose sizes please - 3.2mm i.d., 3.4mm etc? Also, I will ne running on veg oil so may as well fit hose that is tolerant of that. I have searched for a thread on this but did not find one.