dirt catcher for rainwater tank & reusing PVC

Well I finally got around to one of my "gunnas", been on the list for just over two years (ever since we moved into our house). There are commercially available "first flush" gizmos that divert the first few litres of water so that you don't get all the dust that's built up on your roof since the last rains. My method has no moving parts and only costs a few dollars. Basically it consists of a T junction (actually an inspection opening-I.O.) cut into a horizontal run of pipe. This has a length of pipe (about 1.5M) running down to an easily accessed height and a screw cap on the end.

Any dust generally drops out of the flow and into the vertical pipe. It will also catch some leaves etc. A small hole (1/8") drilled into the cap will ensure that the pipe empties after the rain is finished, thus preventing it from becoming a mozzie breeding site. We had a bit of rain the day after I fitted these to my roof, first rain for about a month and there was about a cup of black sludgy dirt in each one afterwards.

One of the downpipes ran down about 300mm and then to the nearby tank via several bends. This required fitting the T piece instead of the first 90 deg bend and then reusing the rest of the fittings. I could have just cut the pipe and used a joiner but I wanted a neater job (and I'd forgetten to buy a joiner :o ) . So, how did I get around this?

It's possible to reuse PVC pipes or fittings in a pinch (but not both!) With larger diameters it's handy to have help, but you can do it by yourself. If reusing a fitting cut the pipe off about 50mm from the fitting. Saw along the length of the pipe. You're trying to split the pipe without cutting into the fitting. You probably won't split it completely but the more you manage the easier it will make it later.

Working quickly:Apply PVC solvent cement liberally to the inside of the pipe (or get your helper to do it) and then cap the bottle and take it away. Light up the glue and as soon as it's finished burning blow out any flames that may still be burning on the PVC itself, grasp the pipe with pliers just next to the saw cut and roll it up, peeling it away from the fitting (a bit like opening a can of corned beef). It may take several applications of glue if the pipe has been glued for any amount of time.

Make sure you cap and remove the solvent cement to a safe distance (otherwise BOOM! :eek: ). Hold the pipe and fitting so that the flames are drawn out of rather than into the pipe, otherwise you will soften and distort the fitting. Two or more sawcuts will make it easier. Have a fresh piece of pipe handy to push into the fitting to mould it true if it's been distorted. Avoid breathing the fumes from the burning glue and PVC, it's nasty!
This is really only worthwhile if you're caught out, you won't be using it as a method of recycling used fittings. Lastly, this is definitely not suitable for use on pressure fittings. It may be of help in some of the more complex dust extraction systems some of you are building (ie: bugger, I just glued that bend on 180 deg out of alignment!).

Mick
PS, wouldn't hurt to have an extinguisher handy ;)

I have reclaimed fittings by cutting the pipe about .5" proud of the fitting.
Cut a long slit on the inside of the remnant pipe with a tenon saw.
Then hammer a screwdriver or chisel on one side of the outside of the pipe collapses the pipe and it all comes out quite easily.

Did help setting up my Dust collector ducting as I miscalculated the fittings I needed so into the scrap heap and recycled some.

Bob,
using the hammer and chisel method works ok if the pipe hasn't aged and gotten brittle, otherwise heat is neccesary.

Mick

I'll keep that in mind Mick

Quote:

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Originally Posted by journeyman Mick

Lastly, this is definitely not suitable for use on pressure fittings.
Mick
PS, wouldn't hurt to have an extinguisher handy ;)

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:eek: :o :o :o :o :o :o :o

Thanks for the PVC tip Mick, one for the memory bank, and the homemade diverters sound like a good idea for those on tank water.

Keep sharing the knowledge.............cheers...........Sean

Yes, good one Mick. The old man and myself were planning on trying to make some of the moving ones but the short vertical drop sounds like a good alternative.

With the removing pipe from old fittings trick, I usually saw them off about half an inch proud of the fitting, heat them like you say, and then push a screwdriver between the pipe and the fitting, then lever it towards the centre. That collapses the pipe and you can just pull it out.

Thanks for the tip on PVC Mick. I thought that once that blue solvent glue was on a joint, it was welded solid.
Graeme

i recall a few years back, my father bought me a heat gun. i though, how nice, hes taking an interest in my trade.

Turns out he "borrowed" this heat gun and re routed the entire plumbing system of the commercial swimming pools we had.

the heat gun worked a treat, but died shortly [get it, shortly :D ] after.

Great tip on the First Flush idea. i got a 1000 litre square chem tank that had water based glue {been cleaned out} off my brother inlaw that i am rigging up for supplying water to the garden. i will use your idea for sure. How long would you make the drop from the t peice?

G

G,
made mine about 1500 long.

Mick

Thanks Mick,

G

If you don't like the idea of burning glue a sheet of newspaper rolled up and placed inside the fitting, then lit, will do the job also.
I had a mate who used to rub a hollow in the dirt, pour some glue in and light it - boy! could he get through a tin of glue!!.
Cheers

Quote:

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Originally Posted by GeoffS

I had a mate who used to rub a hollow in the dirt, pour some glue in and light it - boy! could he get through a tin of glue!!.
Cheers

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What a very strange man, with very strange habits. Neat party trick though, getting yourself through a tin of glue. He would need to be careful where he did it though or he may find himself in some sticky situations. :eek:

Thought it was worth resurrecting this thread, I was searching for comments on first flush diverters.

I used one of the prepackaged first flush diverter kits when I installed my tank, even though I couldn't really see the use of the floating ball in the downpipe.:cool: In the box I did however get the T join and access point caps and a nifty little filter so the drain hole wouldn't clog up, so I bought it and installed it.

After a couple of weeks of rain containing various amounts of mud and muck that has been too fine to be diverted at the downpipe head and getting frustrated with both the restricter washer and the nifty filter basket clogging up. I think I have the solution.

I have now removed the filter entirely, replaced the restricter adapter on the bottom of the of flush pipe with one of those dinky two way adapters with little ballcock taps. On one outlet side I reattached the restricter adapter and the other I left clear.

In normal operation I have left the full flow leg turned off, when the restricter clogs I can open the full flow to empty the downpipe (I wasn't appreciating the shower of water down the 2m of first flush downpipe!) before removing the other leg to clean the washer. Now the tank is full I can also leave the full flow leg open so not as much water has to flow through the tank overflow. :2tsup: