Thread: Source for 150mm pvc fittings

Thanks for all the responses folks. Looks like I have some reading and planning to do.

jonathan

I just shoved the exhaust out through the wall, I understand not everyone has the opportunity to do that but if possible do it, it even saves money.

The costs for 150mm are eye watering, until I looked at the invoice I did not realise the 45's were about seven times more expensive. My three times estimation was a stab in the dark. I just got an extension on the credit card and didn't tell the missus, the less information that comes out of the shed the better off she is and I can't get into trouble. I reckon BP should put up a big sign on his site

DON'T USE 100MM PIPE.

Originally Posted by rsser

Good points Chris.

I would add get a pleated filter cartridge for the dusty. Exxy to begin with but will save effort and health big time in the long run.

It's been a while since this thread but reading Bill pentz website he is not overly happy with pleated filters was my impression they filter lots but can leave you with a false sense of security and the cheaper they are the more issue this is. He also talks about if you don't pre-separate the larger wood can punch holes in the pleated filter as can cleaning the filter. The best recommendation regardless of cost saving is to put the dusty outside

Too right on them 150mm prices I remember paying $38 per 90° bend, gunna hate the prices when I step up too 8" mains!

Pellcorp most modern dusty have a deflector to stop the chips blowing upwards, older units may not have.

Originally Posted by Pell

The best recommendation regardless of cost saving is to put the dusty outside

Couldn't agree more

Originally Posted by pellcorp

The best recommendation regardless of cost saving is to put the dusty outside

I suppose for all round noise and dust reduction that is the best. If you don't mind a bit of noise you can have it inside and just exhaust it out through a wall. I suspect filters are largely a ban aid for a problem that should not arise but some people may have no other choice.

Originally Posted by Harry72

Too right on them 150mm prices I remember paying $38 per 90° bend, gunna hate the prices when I step up too 8" mains!

On Bill Pentz site I came across two money saving strategies for 150mm pipe that you may not have seen. I am going to try them out myself.

Make your own blast gates:
Building a Dust Collection Blast Gate

Don't pay for joiners, make them yourself with this free software to generate the right templates.

Pipe Joint Template
Making Pipe Joints

He suggest making 90 and 45 by cutting the pipe to correct angles on mitre saw and gluing back together. For the more complicated Ys, etc you can use his software.

I am going to give it a go as would be immense saving

I pay about $19 for a bend and have been quoted as high as $28 so I think $38 is a bit rich to say the least. $28 was from Reece plumbing and I told him he was too dear and walked out. I have seen the template program to avoid the use of expensive fittings but I reckon it would be a bit tricky to get all the pipes to be joined in exactly the right place so the angles can be calculated as there would be no tolerance like you get in bends. I will leave that one for someone else to try and report back on how it went.

$38 is for a 90°, a 45° was a fair bit cheaper

Well that would work out about the same. I have used 2 x 45 bends throughout instead of one 90 to keep the flow rate up. I have never priced 90 deg bends.

I doubt there would be much in it, the 90° bends are not sharpy bent like smaller fittings.
If you can get your pipe ends cut squarely the transition is quite smooth and mandrel shaped(if thats the word?)

Originally Posted by Harry72

I doubt there would be much in it, the 90° bends are not sharpy bent like smaller fittings.
If you can get your pipe ends cut squarely the transition is quite smooth and mandrel shaped(if thats the word?)

All the pipe flow tests are done "dry" as it were without the air carrying any media. My intuition tells me that air carrying a lot of media as in wood shavings from a planer going flat out would slow down at a 90 more than two 45's. I have no proof of that but I think it would be a fair supposition to assume that it would happen. Mind you it is going to occur in either setup, just to a lesser degree through two 45's though the difference between the two would be far less than in 100mm. When I look at 100mm pipe now I wonder how it flows any air at all.

As for cutting pipe square I use the bandsaw, it does a great job of keeping things square. Just don't let the pipe roll during the cut though I have not found that to be a problem. I have heard of people getting a big fright from cutting cylinders on a bandsaw and the blade causing them to roll and be pulled out of the operater's hands.

Pentz reckons that 2 x 45* is better than 1 x 90* if memory serves. That's how I set up my ducting.

A while ago a kind forum member sent me some tech data that indicated that was not the case. Might have been Cliff. Senior's moment ;-}

Any case, there's a good number of other factors to get right. Distance, dusty HP, and the number and order of machines to suck from. Thicknessers/jointers and also lathes generate a heap of chips and should be closer to the dusty than other machines and tools.

Not the first time a respected figure like BP has been wrong. Was the data done on a flow bench or just using a manometer? I still suspect that if it could be done carrying media the figures might be reversed but I have absolutely no proof of that. The energy carried in the media would tend to make it collide and stay at the boundary edges where friction would take over and slow things even further, just a guess of course. Mind you I could be fussing over nothing for all the difference it might make.

Dunno how the tech specs were arrived at, but I agree, getting the basics right is the main thing. Best advice I can give is to do rough calcs, assume major efficiency loss and so buy a dusty with more horses then you might first think.

I've seen guys buy a small dusty on castors and then kick themselves when it doesn't do the job.