Physics/plumbing question

[Unclejake]

2 hours ago, 440bbm said:

Didn't notice you mention that you had another 20m of 25mm hose at the end of that 140lm. 

The 20m of 25mm hose wasn't installed when I did the visual checks on Tuesday, so you didn't miss a thing. Your advice has been spot on.

I'll have a look into 50mm hose (thank you, I hadn't thought of that), but a 50mm hose would be a heck of a weight to be dragging around a building site, and unfortunately I need it 20m long to get to all four corners so I'll have to make a compromise somewhere. I just need to decide if it's expense/noise/flow/pressure or convenience that I want least.

Edit: I'll do some additional flow checks without the nozzle, then without the hose, hose tail etc. 

Both the upper 'tap' and lower tap will be identical setups.  I.e. 40mm LDPE>40mm ball valve>25mm hose tail>20lm 25mm PVC washdown hose>25mm hose tail>Skellerup Master Blaster nozzle

 

[440bbm]

Ah yes gotcha. There will have to be a compromise somewhere. Maybe its best to see about a pump setup on it. then you can keep everything you currently have and don't have to compromise that part, the compromise will be just be on your wallet  haha/

I forget you are over in timbuktu so just not as easy for you to just get some 50mm hose or whatever, so not ever easy fr you.

[Unclejake]

I'm guessing most everyone is bored with this by now, but it turns out the Skellerup Master Blaster hose nozzle is 'taxing' the system by 19 litres a minute. 

There's nothing wrong with the nozzle. It's just designed for more pressure than I'm delivering it.

I've settled on a smallish, lightish, petrol powered pump to alleviate the symptom. A bigger bore (140lm  long) underground pipe would have made all the difference... but I didn't do my research properly before buying pipe and TBH the cost of a petrol pump is less than replacing the pipe... so that's the plan.

Tomorrow I'll start back-filling all the trenches. After that it's too late to turn back... and I'm OK with that.

Thanks everyone for the advice. Now onto the next drama!

EDIT: I looked at lots of minor brand ~$450 pumps and decided a new Honda from a reputable supplier (who's experienced in sending stuff to Chatham Island) was worth double the money. Consequently the Christchurch Stihl shop got an order for a really light-weight Honda WX15 tonight. The dudes from that store come over here annually to shake hands and peddle their wares so it'll be easier to sort spare parts etc. when things go bad. I'm also guessing the Honda will be quieter than the Xlyongikin/Vellisuckymota equivalents, and at only 10kgs the Honda should cost less than $60 in freight and may be here on Thursday. TBC

https://www.hondaoutdoors.co.nz/wx15-portable-pump

[440bbm]

Thats a good plan.  I used to buy alot of the 2" wb20 pumps and went well. used to be re-fitted and ( slightly modified ) mounted to helicopopters.  Assuming the smaller series is as good as the larger 2" you will be fine.