Experiments with fire hose systems

[flatcat]

Hi,
Today me and my Step brother Jack decided to get the fire engines out to play with, and resultantly the hoses and water pump. However us being our technically demanding selves, we decided that the whole system was not really as good as it could be

For the tests we used just the monitor on the turntable ladder truck as an outlet.

The first two pics show the simple starting setup using just one hose from the pump to the monitor of the 4820:





This setup was okay, but the tank quickly ran out of water after only a few seconds of pumping, so a larger water tank was needed.

[playmofire]

This setup was okay, but the tank quickly ran out of water after only a few seconds of pumping, so a larger water tank was needed.

That's where the first pressurised system scored as it had two tanks.  The xecond tank may still be available from DS.

[flatcat]

It was then that I remembered I had a petrol tanker upstairs which could be used to hold lots more water. With a bit of quick customising it was soon turned into my brigade's water carrier:



This was soon put into line between the pump and the monitor, leaving the pump empty. After experimenting a bit we found that the water tanker should not be filled right up to the top so that air can be pumped in and filled up. Also by not using a connector on the pipe from the pump into the top of the bowser meant that there was minimal air leakage (just by stuffing the pipe in the top). We also made sure that the lid on top of the tanker was done up super tight.

However, with these pressure saving tips, there was not enough pressure supplied by the pump to fill itself up, and force the water from the tanker up to the monitor of the 4820. So somehow we needed more pressure

[playmofire]

Ooooooooooooops!  Sorry for jumping in too soon!      I guess there's a solution coming up to the second problem.

[flatcat]

Then Jack had a brainwave, and soon the small red pump was replaced by a small football pump with the needle adaptor stuffed in the end of the hose:



It provided some more pressure, but a continuous flow from the monitor could not be obtained due to every time the pressure ran out and the handle was withdrawn to pump again, it sucked the remaining pressure back out of the system. So this did not work.

[flatcat]

Finally we gave it some welly using a bicycle floor pump, again using the needle valve attached:



This gave us our pressure and continual flow of water with just one pump of the handle. However any more pumps than that was making the roof of the tanker buckle outwards due to there not being a pressure releasing device anywhere like on the PM red pump.

We had to sort this out somehow by not losing any pressure before it got to the monitor, but by getting the water out as quickly as possible

[flatcat]

Our solution was to enlarge the hole of the nozzle, and so off we went outside into our workshop:




We found the smallest drill bit we had, and then Jack dropped it on the floor





There it is!:




We then put the drill bit in (it is there if you look closely!) and Jack carefully drilled through making sure the piece was in line by clamping the machine vice down to the table of the drill:



The new end turned out well and it was ready to test.

[flatcat]

Here are pics of the narrow hole compared to our newly enlarged hole one!





It gave us just the relase we needed, but of course you could get away with using the original end if more appliances are attached to share the high pressured water.

Thanks

[playmofire]

Thank you both for that very informative (and entertaining) account of your experiments.  There are ideas there worth following up.   

[flatcat]

We couldn't help ourselves













It actually worked surprisingly well. Jack set the machine for 7psi, and when the pressure dropped to 4psi the machine would automatically come on again to keep the supply of water constant