Twin feed machines are built specifically for Q-Washers (Damien) by a company called Nailsea power cleaning based in Bristol.
The idea with this is that using two feeds allows a 21lpm or greater pump to feed better and with less cavitation / water resistance whilst also keeping the outer piston supplied with water.... BIGGEST LOAD OF BS
Yes the actual inlet port on most pumps is only 1/2 but its getting the maximum amount of flow to this point with minimum resistance that is important. Splitting the feed theoretically splits the priming ability of the pump... DP who deal with interpump warranty are declining to deal with warranty on twin fed machines supplied with 1/2 hose.
Look at the THOR machine for instance 1 1/4" hose 51LPM
Firstly the feeds on these two feed machines are done in 1/2" hose on a Brass coloured weighted filter which has at its smallest point an 11mm hole. Every time water meets any fitting or metal surface this causes friction which causes the gases suspended in the liquid to break down (air bubbles).
Using a single 1" hose and feed reduces friction exponentially by reducing friction on the water by decreasing the overall contact area with the water, this reduces cavitation and allows the pump to feed better. consider a centrifugal pump - on 1" hose you can pump up to 500 lpm? This surely raises question when you are told you cannot feed 21 on 3/4"?
Up to 21LPM we use 3/4" hose with 3/4 filters etc Q use 2 x 1/2 y strainers again the more fittings you use the greater the resistance.. this water then has to go through the quick release fittings - through the hydraulic fittings uses to get the water around the corner... NEVER put an inlet on a bend.... like a river which erodes on the inner bend caused by the breakdown of suspended air molecules which then erodes than bank and migrates the path of the river- you are drawing this air into your pump.
The idea that the outer piston is starved of water is rubbish - until you get to the K series @ 500lpm 1000 Bar you have 3 pistons which reciprocate in the same way a car engine would, only one piston is using the water on its outlet stroke at any one time, the other pistons are on the inlet or pre inlet stokes pulling water into the pump... how can one be starved? Admittedly on most pumps the use of an easy prime valve is essential to aid priming - it is always better to positively feed a pump with gravity rather than sucking / drawing water from over the top of something, again the U shape created in the pipe holds a small amount of air which again interrupts water flow.
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Sorry if boring but thats most of how it works any questions do ask
Might be able to sort out a discount for CIU members......
GOOD IDEA
