Ducting for dust extractors

[martc]

I just bought a dust extractor for my workshop but I have no knowledge of the best way to do the pipe work for my machines.
The extractor has two 100mm inlet pipes one has an end cap so I have attached my first bit of pipework to the other inlet, I am using 110mm sewage pipes for the main trunking running up to the roof and the full length of the workshop (about 7 meters in length).
My question to the experts is what is the best size pipe to run from the main trunk to my machines, I was thinking of reducing to 50mm waste pipes would this work or would it be better to run 110mm to each machine?
The extractor has a 250mm impeller moving 1490cfm
Thanks

 

[9fingers]

Always keep the diameter as great as possible for as far as possible. The friction in a pipe increases as the diameter drops so the air flow drops drastically.

If you glue a blast gate into the open end of 110mm pipe with a foaming glue (PU), it forms a convenient 110 to 100mm conversion, then use 100mm flexible pipe and then only if the machine has a smaller dust port, make an adaptor (from wood?) down to the final size.

HTH

Bob

 

[chataigner]

Always keep the diameter as great as possible for as far as possible. The friction in a pipe increases as the diameter drops so the air flow drops drastically.

If you glue a blast gate into the open end of 110mm pipe with a foaming glue (PU), it forms a convenient 110 to 100mm conversion, then use 100mm flexible pipe and then only if the machine has a smaller dust port, make an adaptor (from wood?) down to the final size.

HTH

Bob

:text-+1: Try also to keep as much of the pipe run as possible in smooth bore pipe, the corrugated flexi has much higher resistance and so pressure/flow loss.

 

[DaveL]

And try to avoid 90 degree bends, I used pairs of 45 degree bends and 45 degree Y junctions followed by a 45 degree bend instead of 90 T junctions.

 

[Wizard9999]

And try to avoid 90 degree bends, I used pairs of 45 degree bends and 45 degree Y junctions followed by a 45 degree bend instead of 90 T junctions.

Do you tend to put the two 45 degree bends next to each other, in effect increasing the radius of the corner?

Terry.

 

[DaveL]

And try to avoid 90 degree bends, I used pairs of 45 degree bends and 45 degree Y junctions followed by a 45 degree bend instead of 90 T junctions.

Do you tend to put the two 45 degree bends next to each other, in effect increasing the radius of the corner?

Terry.

Yes, you are trying to make the path for the dust to be as smooth as possible, any sharp change in direction will cause the air to slow and that will allow the dust to drop out and collect in the pipe.

 

[Wizard9999]

Anyone tried this stuff for dust extraction?

http://www.screwfix.com/p/manrose-round ... _container

Is it robust enough? Is it interchangeable with the stuff from Axminster et al? If it is any good it looks a fair bit cheaper, though the range of parts is limited, hence the question on interchangeability.

Terry.

 

[9fingers]

Would appear to be in 350mm lengths???
Need connectors every 14" which pushes the cost up.
Wall thickness is possible 1mm so will need lots of support.

I'd stick to 110mm soil pipe from toolsatan who were cheapest last time I checked.
About the only application would be to make extraction stubs for things like router tables, mitre saws etc and couplers for 100mm flexi. I use French 100mm soil pipe for this though and am well stocked currently so no need to try the Screwfix stuff which I think is made for kitchen extractors.
Before anyone suggests the tumble dryer flexi hose - it is far far too fragile for workshop use.

Bob

 

[Wizard9999]

Would appear to be in 350mm lengths???
Need connectors every 14" which pushes the cost up.
Wall thickness is possible 1mm so will need lots of support.

I'd stick to 110mm soil pipe from toolsatan who were cheapest last time I checked.
About the only application would be to make extraction stubs for things like router tables, mitre saws etc and couplers for 100mm flexi. I use French 100mm soil pipe for this though and am well stocked currently so no need to try the Screwfix stuff which I think is made for kitchen extractors.
Before anyone suggests the tumble dryer flexi hose - it is far far too fragile for workshop use.

Bob

Bob

Hard to see how Axminster can justify >£16 per m when tool station is a sixth of that price. How would you suggest coupling the 110mm to the 100m, it doesn't look as thought the heat shrink stuff is that big (50mm if I read it correctly.

Terry.

 

[9fingers]

Terry, if you read my pearls of wisdom(?) above. I have described how the transition is done.

At the risk of upsetting at least one member here, Axi charge that much because they can and sufficient mugs buy it from them.

100mm piping has little other application in UK whereas in many parts of Europe is is standard sh1t pipe.

hth

Bob

PS usually underground 110mm is a bit cheaper still as it does not have the ultraviolent stabiliser in the plastic.

 

[stephen.wood125]

I've been looking at this place recently:

http://www.ductstore.co.uk/index.html

I'm not affiliated etc.

I'm thinking of trying to use majority 125/150mm spiral steel ducting and then some 100 for the smaller machines.

bscene-drinkingcheers:

Steve

 

[martc]

Right thanks for the info, I have very limited space in my workshop so will have to come up with a plan to get the 110mm to the machines. Because my workshop is so cramped I have to keep moving things like the table saw to make room for longer material to be worked on so flexi pipe would be ideal for me however I am struggling to find any flexi pipe over here, will have to look at a few other places.

 

[Woolf]

Hardware Centre in Strijdom Park had flexihose. Don't know if they still have. I bought from them a year or two ago. The also have blast gates and various other fittings.
http://www.hardwarecentre.co.za/web/

 

[martc]

Thanks woolf, I will have a look at their place when I get a chance.