Submariner1
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- CL500 2009 5.5
I am just interested 'in the principles' of the advice on a commercial pressure washer to have a 7.5 meter 3/4" feed hose.
Purely from an enquiring mind point if view.
OK I understand a 3/4" hose can deliver 4x the flow rate. But all the connectors are eventually contricted by the bore of the std. 3/4 BSP tap connectors at either end.
My lack of understanding, is further compounded by the fact they advise using a micro filter, that also has the same tap connectors.
My lack of understanding of Physics ( ergo fluid dymanics ) makes it puzzling.
Surely the overall flow is limited by the internal bore of the smallest connector, in this case these are the 4 tap connectors (note they are the same bore as your std. 1/2" Hozelock jobs).
E.g.
Mains - Tap - female 3/4 connector - hose - female 3/4 connector - Tap - Microfilter - Tap - female 3/4 connector - hose - female 3/4 connector - Tap - Power washer.
* Tap = 3/4 BSP tap connector.
Initially I assumed the min length of 7.5 meters of 3/4" hose was supposed to act like a mini "buffer reservoir", in case your mains pressure dropped for a short spell.
But the additional ( and imo sound ) advice to put the micro filter close to the washer, kinda negates the reservoir buffer theory.
I can only assume, the 3/4" hose delivers enough extra flow (less resistance on curves etc.) to create significantly more pressure at the constricting tap connectors; to overall provide a better flow rate.
But maybe it doesnt work like that
OK I just did it in 3/4" as I needed 10m more length for the system anyway, and the comi boiler only delivered a HOT flow of 12.5L per minute ( where the m/c recommended 13 L) using a std. 1/2" hose.
Note on cold it delivers 21 L.
I am hoping the 3/4" hose might up the Hot flow to 13L/ min but no biggy as the m/c output is only 10.9L per min; so only delivering 12.5L wont starve it. Plus the fluctuations due to the time of day are probably much bigger.
My decision was also seriously influenced in the fact I could buy industrial 3/4" connectors cheaper than your bog std. Hozelock 1/2" ones ... so why not.
But I would be interested to know how fluid dynamics actually work.
Purely from an enquiring mind point if view.
OK I understand a 3/4" hose can deliver 4x the flow rate. But all the connectors are eventually contricted by the bore of the std. 3/4 BSP tap connectors at either end.
My lack of understanding, is further compounded by the fact they advise using a micro filter, that also has the same tap connectors.
My lack of understanding of Physics ( ergo fluid dymanics ) makes it puzzling.
Surely the overall flow is limited by the internal bore of the smallest connector, in this case these are the 4 tap connectors (note they are the same bore as your std. 1/2" Hozelock jobs).
E.g.
Mains - Tap - female 3/4 connector - hose - female 3/4 connector - Tap - Microfilter - Tap - female 3/4 connector - hose - female 3/4 connector - Tap - Power washer.
* Tap = 3/4 BSP tap connector.
Initially I assumed the min length of 7.5 meters of 3/4" hose was supposed to act like a mini "buffer reservoir", in case your mains pressure dropped for a short spell.
But the additional ( and imo sound ) advice to put the micro filter close to the washer, kinda negates the reservoir buffer theory.
I can only assume, the 3/4" hose delivers enough extra flow (less resistance on curves etc.) to create significantly more pressure at the constricting tap connectors; to overall provide a better flow rate.
But maybe it doesnt work like that
OK I just did it in 3/4" as I needed 10m more length for the system anyway, and the comi boiler only delivered a HOT flow of 12.5L per minute ( where the m/c recommended 13 L) using a std. 1/2" hose.
Note on cold it delivers 21 L.
I am hoping the 3/4" hose might up the Hot flow to 13L/ min
but no biggy as the m/c output is only 10.9L per min; so only delivering 12.5L wont starve it. Plus the fluctuations due to the time of day are probably much bigger.My decision was also seriously influenced in the fact I could buy industrial 3/4" connectors cheaper than your bog std. Hozelock 1/2" ones ... so why not.
But I would be interested to know how fluid dynamics actually work.
