Refigeration Pipe sizing

[Goober]

Does anyone know where I can obtain software, if available, to work out the required liquid and suction pipe sizes required for any given capacity. Engineering data supplied by my wholesalers gives rule of thumb sizes only upto 30m. From practical hands on experience I could probably hazard a damn good guesstimate. But for peace of mind I would like to back it up with proper engineering data. Metric software or calculations please!

[750 Valve]

I added a couple of links to 2 programs in the following thread

http://www.refrigeration-engineer.com/forums/showthread.php?t=9587&highlight=dircalc

[Goober]

Thanks for the links, also scored a Sporlan package from one of my wholesalers, works great. However I have another question.....Pricing a job that has a 100m pipe run. 19.4 kw, evaporating at -5.6C. Predominantly straight horizontal run. Liquid and suction to maintain the spec'd velocities work out to be 3/4 & 1-5/8. Single evap to single condensing unit. Now....Is there ever a need to stagger the size of the suction: ie getting bigger as you get closer to the cond unit or vice versa......can't quite get my head around it.

[Goober]

Ok Ok, it must have been a stupid question,judging by the lack of replies. It was my work colleague who planted the seed of curiosity regarding staggered suction pipes on a single run sytem. So nobody has ever seen/done this? I never have and I've worked on some big supermarket systems, albiet mostly Racks.