Having Fun With Some DIY Plumbing

[marvoni]

We're in the middle of a drought with 'day zero' estimated around May next year so I've decided to go off grid, or partially off grid in an effort to ensure I still have water at home.

I decided to use my borehole water for most of the house and just use council water for human consumption such as drinking and cooking. This has meant I've had to split the plumbing into two circuits, borehole water now supplies the 5 bathrooms and council water supplies just the cold water on the kitchen sink, the coffee machine and the soda machine which are both permanently plumbed in. There's also an option to revert back to council water for the entire house as well.

It's meant some serious DIY plumbing, although probably not plumbing as you know it, over the last month or two.

 

[ShaunCorbs]

looks fine marv

 

[marvoni]

Thanks Shaun, hopefully I'll get it finished this week if I can find time.

 

[neilrj]

You have too much time, tools and talent...

 

[oz-plumber]

I'm glad to see you South Africans use silver solder - much like us Aussies.

 

[marvoni]

Lol, thanks for the comments. I used a copper welding rod, I'm too much of a cheapskate to use silver solder unless it's dissimilar metals where it's the only option.

The blank end cap that went on last I just used normal plumbing solder, that way I hedge my bets in case I need to remove it again (see photo in next post).

 

[marvoni]

I finished the assembly and installed it this morning. Here's the finished product (which I've been officially calling a prototype so I've got an excuse for the rough looking construction)....

 

[ShaunCorbs]

Have you tested it yet ?

 

[marvoni]

I tested it at various flow rates and it works very well (I'
d hazard nearly 100% efficient) up to around 12-13 litres per minute. At flow rates up to that point it removes all the air and ejects literally a drip or two of water each time the solenoid operates.

Between 13 and 20 litres per minute flow it progressively ejects more and more water along with the air. At 20 litres per minute it ejects about a shot-glass worth of water each time it dumps the air.

Above 20 litres per minute there's air getting carried through and at 25 litres per minute there's about a cup full of water ejected each time it dumps air.

I think what's happening is two things, firstly above 20 litres per minute the water velocity through it is too high for the air bubbles in the water to completely float and separate hence some air getting carried through.

Secondly I think the internal turbulance at higher water velocities is causing froth or foam at the top instead of clean water/air separation so when the solenoid opens it's actually dumping froth which accounts for the increasing water coming out of the dump pipe each time as the flow rates go up.

 

[ShaunCorbs]

Sounds like it needs making bigger dia and length also some internal baffles

But it's a proof of concept

 

[marvoni]

Have you tested it yet ?

Sorry, I wasn't trying to build anticipation, I only type with one finger so posts take time.

As it is, the only time the flow rates to the house get high enough to cause the separator problems is when the kitchen sink hot tap is opened full bore to fill the sink. At all other times including when people shower, flush toilets etc the separator works admirably.

We've got 5 bathrooms so there may be a 'perfect storm' type scenario if there's guests staying or if 2 or 3 people happen to shower or flush toilets simultaneously and the separator doesn't cope but TBH I'm not that worried, it will just serve to make everyone in the house mindful that we're over consuming.

At some stage in the distant future when I've got nothing better to do I may just reconstruct it using the same components and general design but a larger diameter pipe. I'd probably go with a 100mm pipe which would give more than double the volume and half the velocity of the 67mm pipe I used.

 

[marvoni]

I already have an idea for Mark II. We dug out some threaded fittings from stock in my fabrication workshop and I purchased one extra end cap which I was short of.

 

[ShaunCorbs]

I would get a longer nipple

 

[marvoni]

The assembly is going to be considerably longer than the first prototype.

We don't have a supplier for longer nipples so the only option would be to add another nipple and socket. After what it cost me for the extra end cap today I don't relish the idea of buying more fittings TBH.

 

[ShaunCorbs]

You going to tig them together?

 

[marvoni]

I'm undecided. I might Tig them all except for the bottom cap so I can open up at a later date should the need for maintenance arise. I might also just use high viscocity /high strength threadlock or Stag paste and hemp and hand screw them all together. Any suggestions?

The PRV is set around 3 bar and the maximum pressure is limited by the capability of the borehole pump which is only capable of 4 bar so I'd imagine either method would be adequate.

 

[ShaunCorbs]

I would tig them together to give you maximum length

But looks good so far esp for a mk2

 

[marvoni]

I'm thinking about Tig welding 1 inch sockets (or maybe inch and a quarter) onto it for the entry and exit pipes. Hopefully larger diameter pipes will lower the water velocity entering in and exiting. I'm thinking that lower velocities will equate to less internal turbulance and better, cleaner, faster separation of the air. I'll also revisit the idea of internal baffles, there's quite a bit more internal space to accomodate them this time around.

I could draw the unit and baffle arrangement up in CAD and do a basic simulated model of the water flow but it might be more fun to set up a pump and flowmeter and do some real-world bench tests with a few different designs. I'll see how much time I can find to play with it....unfortunately I've got real work to do as well so playtime is limited.

 

[Chuck]

I'm undecided. I might Tig them all except for the bottom cap so I can open up at a later date should the need for maintenance arise.

Good idea. If it were my project, I'd be worried about the potential for stagnation and biofilm growth inside the separator. I would want to made sure it was convenient and easy to open fairly regularly for inspection and cleaning/maintenance.

 

[marvoni]

Here's a pic of MkII next to MkI to give a better idea of scale. The threads were screwed to half way which is roughly where they'd be using hemp and paste. The overall length would be around 30-40mm longer if I TIG weld it but I don't think it will have much effect on the efficiency TBH.

 

[ShaunCorbs]

DIdnt realise it was that big

That is a beast

 

[marvoni]

Didn't get around to finishing the MkII air sep but I did manage to get some filters installed.

 

[marvoni]

There's light at the end of the tunnel now, I've got one more activated carbon filter and a UV-C steriliser left to install then I'm finished. Those two items will mean I can go off-grid entirely even with my drinking water should the need arise.

 

[marvoni]

I installed the UV sterilizer and the drinking water filter this weekend.

The UV-C tube in the sterilizer has a life rated at 8000 hours. This is about 10 months if it runs continuous so I wat to install controls so it only operates when there's water flow.

I need a flow switch that can give me a signal for water flow between 0.2 and and 25 l/min. I'm struggling to fine something suitable that doesn't cost a fortune and there's also very limited options in this neck of the woods as far as stock available of the shelves.

I thought I'd give it a bash with fabricating my own and I've been mulling over a few ideas but I'm not sure the best way to go about it. I thought I might use a standard brass check valve to give me a small pressure drop and use that to cause water flow in an auxilliary circuit to cause a shuttle in a sleeve to raise against gravity. If the shuttle has a small magnet on the top it could operate a reed switch mounted externally if all the components and non-magnetic.

I'm not sure if this is the best way, there's a lot of variables involved and I've got a suspicion it could get a bit messy with the tolerances and the tweaking involved to get it to work. Anyway, I did a sketch which is below, if you've got any advice or better ideas on a completely different track please let me know.

 

[oz-plumber]

I don't think you should be too concerned about replacing the globes.
The biggest issue we come across is the tubes have a build up on them reducing the efficiency of the globes.
My main concern for you would be to keep the tubes clean.
Check them at 3 monthly intervals or less if you like.

It would be far better to have the globes running constantly to protect the water supply than have them switched by a flow switch.

 

[sammathias]

The 15 and 22 bends were done with one of theseView attachment 32217

The bends on the 3/8 refrigeration pipe with one of these
View attachment 32218
I have some spring benders but I've never found them easy to use and be accurate. Probably just need some practice.

I have one of them 3/8 benders!!! my granddad passed them down and I deemed them useless until It dawned on me that thay are perfect size for bending plastic coated 10mm oil line!