Well after months of reading every bit of info i can find on dust collection system design. I,am ready to start putting mine together and i would like to share a few things i think i,ve learned. The first thing is most small shops will use a 2hp or smaller collector or vac which ever one you like best. The next thing is the duct work or piping in most shops use 4” sch 40 pipe because its cheap and easy to purchase. But heres the rub. The 90 deg fittings for this pipe is very restrictive. They tell me one 90 is equal to ten feet of pipe true or not. That’s not the problem. After years of working with a flow bench building racing cylinder heads, theirs a few things that are a constant any time air flows around a corner. It slows down a lot. It also go straight across the port or 90. Air don’t like to turn. This creates low pressure aera in the small side of the 90. This fact means that when trying to carry something like saw dust it drops it going around the corner causing it to plug up your pipes. After some research you can buy 4” sch 40 conduit bends that have a 36” arch you will have to use a little heat to fit them together but they will work. – – – The next thing is connecting machines onto the duct i recommend using Y,s with long 90 for this. Tee,s wont work they do the same thing the tight 90,s do, Cause restrictions, this is something you always need to avoid when planning your system. The next thing is collecting the vast majority your waste at the machine. I know every body knocks the trash barrel separators but they do what their design to do.The 4” pipe these small systems use cannot move the large amounts of waste some of your machine create. plus they plug your bag up in a couple of minutes reducing the vac flow. – – -I recommend installing pvc clean outs so that all the joints can be glued so their sealed. It sure is a shame The people that mfg the dust fittings that everybody sells are not made to slip together and fit right into pvc pipe with out adapters maybe someday!!!! – – – I see a lot of people build and seal up their machines try to suck the saw dust up but if you plug it up to tight you will loose air flow and it will not carry the solids to the collection bins. I recommend installing a water column gauge just outside the vac unit and adjusting your air flow so its as high as you can get it at the machine. After a while you will be able to listen to it and adjust your gates as needed. – – – In closing, design your system with the least amount of 90,s as possible use the longest radius 90 you can get. Seal your joints install clean outs their cheap. use Y,s no tees collect as much of you waste at the machine don’t try carrying all the way to your vac it just causes problems. I will include pictures of my system as soon as its done. – – – Thank you for reading my thoughts Please comment as no idea is not to be explored. – – Note the 4” conduit also has 45 deg and offsets if needed. their reasonable priced.
-- BIG geo ---Occam,s razor The simplist answer is often correct