Matrix Pump

[TerryJC]

Now that the Sump SAC and the associated Gate Valves appear to be working, I am left wondering about what I should do next. Clearly, the Matrix Pump has little point if the Lady Hanham system isn't working, but we will eventually need to install and integrate this pump if the system is to ever achieve full functionality. I could therefore manufacture the four Gate Valves against this future goal. This is what I had started to do before lockdown.

There is a snag however. Over the years we've had several Pi Zeros 'blown up', mostly by me during development activities admittedly, but the most recent occurred when the local wildlife contaminated the Stage Gate Valve. As a result, I have no new Zero's available for use. However, there are still three Zeros that are part of the original Matrix Pump Build and one that is part of the earliest SAC that I built and kept as a reference model. The carcases of the original build were scavenged to allow me to repair the Valves that had been suffering from the brittle wiring issue that was identified during Lady Hanham equipment testing.

Other than that, Zeros are now as rare as Rocking Horse droppings, owing to the global chip shortage. The usual suppliers are out of stock and the scarcity has generally inflated the second hand market so that they are three or four times their usual price (officially £4.80). If I use the four that I have there will be no spares available and a failure of a critical Valve or SAC could leave the River System completely non-functional. However, apart from the most recent event Pi Zeros have been pretty reliable, so this would probably be a minor risk.

My question therefore is; should I get on and refurbish the remaining Gate Valves and consume all the Zeros we have, or is there another task that I should be doing?

[Penri]

Hum interesting.

Perhaps getting to an answer in a convoluted manner or just adding more to think about.

• When we did have the Hanham Butts in place (pre-dismantling) they didn't seem to have any problem in emptying themselves into the Wendy Butts / Sump, so the need for mechanical assistance to help is probably not required.

• The Stage Butts never seemed to fill particularly well when it rained, possibly the trees providing an umbrella type effect and/or the stage roof area no being particularly large.

• We never got the chance to compare how quickly the Hanham Butts verses the River System / Wendy Butts filled when it rained to see it our idea of pumping water from the Wendy Butts to the Hanham Butts was required.

So taking all that at face value, I'd say that we probably don't need mechanical assistance to get water to the Wendy Butts / Sump but could do with it taking the water away from them to the Stage Butts and possibly Hanham Butts. That would simplify matters considerably to just installing the pump to move water away from the Wendy Butts and let water flowing towards the Wendy Butts just flow through it (the pump turned off). If that was considered to restrict the flow too much (I'd need to pour some water through it the "wrong way" to see what happens) we could install a bypass gate valve in parallel to provide an uninhibited path.

This proposal also has the virtue of being much simpler to implement plumbing-wise.

Thoughts?

Penri

[TerryJC]

Penri,

I'm not sure how the bypass valve would work. Where would it be and what would it bypass?

Also, I presume it would be activated from the Wendy Butts Pi?

[Penri]

I’ll produce a sketch.

Yes the Wendy Butts Pi would probably be the place to activate it from.

[Penri]

Herewith a very simplified sketch of the proposed Butts water system showing the pump and bypass valve.

In operation:

• When the River System / Sump and Wendy Butts are operating normally the Stage, Hanham and Bypass valves will the closed and the Pump off.

• When the Wendy Butts and Sump are full but there is capacity in the Stage or Hanham Butts the Pump would be activated to move the surplus water to those butts as directed by their respective valves, the Bypass Valve would be closed.

• When the Wendy Butts / Sump need water and some is available from the Stage or Hanham Butts the appropriate butts valve is opened together with the Bypass Valve.

The Bypass valve's only function would be to increase the flow capacity back to the Wendy Butts / Sump if the Pump when off would prevent or greatly restrict the amount of water flowing through it in the direction of the Sump /Wendy Butts.

UpstreamPump.jpg (305.95 KiB) Viewed 236 times

Does that clarify my proposal?

Penri

[TerryJC]

I see. The only problem with that is that the amount of fall in the system. Clearly the pump will do a good job of moving water from the Wendy Butts / Sump to the other Butts, but with no assistance the water will only return until the levels are equal. The water backup strategy would assist that of course because the water in the system could be pumped up to the Stage and Lady Hanham butts until they are either full or there is no more water to pump, but by then the difference in the levels could be considerable.

A good compromise.

[Penri]

I agree and I suppose that it all depends on what level of water is in the Stage or Hanham Butts when we open their respective valves.

Having said that my experience, when operating the Stage and Hanham valves by hand, was that the respective Butts drained themselves completely when given the chance. I don't know what the mechanism was the drained them, perhaps a siphon was set up into the Sump that effectively sucked the water out.

Worth setting this as a revised way forward?

[TerryJC]

Worth setting this as a revised way forward?

Yes.

[Penri]

In which case I’ll make sure I have the required joins and pipe and schedule it in.