[Matt Gibson]

I dont see the point in using a larger feed hose as the inlet on the pump is only a certain size (1/2" from memory)

[wpclean]

I am confused ( doesn't take a lot ) 

[Ben Marriott]

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.
\
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

[wpclean]

That is easy for you to say 

[wpclean]

Thank you for that in depth answer.      Will my machine be actually producing 21 lpm  with the twin inlet feeds then ?      I do love the Honda machine , it is really well weighted for mobility.

[Ben Marriott]

Thank you for that in depth answer.      Will my machine be actually producing 21 lpm  with the twin inlet feeds then ?      I do love the Honda machine , it is really well weighted for mobility.

Without putting it on a flow meter it is difficult to tell - I can't image that it will be far off 21lpm the point is that its false marketing for something that isn't necessary to begin with. I will set a machine up over the next few weeks on the same set-up and take some pictures of the results and post them, our paid thread should be up by then too, so I can put it on there.

The GX series are good engines - they are getting thirstier on fuel for some reason.

[wpclean]

It is interesting  getting different opinions about the washer setups.    Damian at Qwashers is passionate about pumps, and he swears by the twin feed system.      He is the old type of tradesman in that he only sells stuff that is made to last, and he spends ages talking you through the system.
I love going up there in the sticks, and watching him work, and listening to him.  Real family man too, and lovely seeing him pass on all his knowledge to his son.          He is not a a hard sell guy either, he has worked on stuff for me, and there is no way he has earned a penny profit doing it, he just loves his job 

[chris scott]

Did not know it was that technical….I just thought a Gx390 was to small to turn a ws202 under load.
You learn something every day!

[Ben Marriott]

At the end of the day no matter who builds the machine they are sold through a distributor - Q Washers - Tech Clean - Spinaclean etc whilst they have the kit to sell them and repair them most won't spend the thousands of pounds required to get these machines tested properly.

To get VOSA in to certify for noise, vibration, load and pressure costs £495 per machine you have to have 5 of every machine you plan to build tested. So not only does it cost the best part of £3k per model you have to have 5 of very machine built up for them to drill holes into and then put sensors in. It costs a bloody fortune to make these things not only that but there is only 3 companies in the UK who interpump will sell to direct - Honda will only sell direct to certain people based on order volume, Briggs are even more particular as they won't let me manufacture with any other petrol engines.

A bucket is not the correct way to test a pumps efficiency or capability.... without knocking Nailsea in anyway there is a reason 90% of the machines built and sold globally do not use this dual feed system and if Interpump suddenly decide no more warranty it will get very expensive for them. Jetmac make some great stuff and some stuff I think is crap but he has said many times that like me he spends the better part of every call explaining why dual feed is not required.

I buy some nailsea machines for customers but Dave knows not to come near me with he dual feed tripe because he knows I'll ask him to prove it

 

[Jettaway]

Thanks for the detailed answer Ben.  You raise some good points in regards to bends etc.
So if Interpump don't want their pumps dual fed then why do they manufacture 2 inlets into their ws202?

[Matt Gibson]

So you can have the feed in either side, depending on how your pumps mounted etc..

[Smudger]

Thanks Ben, saved me a lot of typing there !!

The guys at my local pressure washer place have said virtually the same ( they supply nilfisk posiden and there own brand - commando )

Darran

[Matt.]

Interesting regarding hose in tank and having to suck water out the lid and over the top of tank, i have to use the tank I use for pure, would like a second tank but it's the space thing........

How would ya go about fitting the inlet hose into the lower part of the tank or is there a fitting you could add to the tank to supply machine, and how would you prevent any crap being sucked through

As always Ben........ Top post and great info

[Ben Marriott]

How would ya go about fitting the inlet hose into the lower part of the tank or is there a fitting you could add to the tank to supply machine, and how would you prevent any crap being sucked through

I'd use a bulkhead fitting depending on the type of tank. Essentially you drill a hole and have a long threaded hollow tube with two rubber washers which you tighter against the tank to seal it - on the inside you can then put a basic mesh foot filter of any size and then on the outlet your hose barb to connect the outlet hose.

As always Ben........ Top post and great info -- CHEERS 

[Smudger]

I've always gravity fed from a tank ( converted wheelie bin ) you can get a variety of tank connectors to drill in lower down.

Now feeding from 1000 litres IBC tank with 2" outlet, didn't need to find a mains supply at all today 

Darran

[Ben Marriott]

I've always gravity fed from a tank ( converted wheelie bin ) you can get a variety of tank connectors to drill in lower down.

Now feeding from 1000 litres IBC tank with 2" outlet, didn't need to find a mains supply at all today 

Darran

MUCH EASIER!!

[Matt.]

Thanks Ben, will you add what I need to my list please 

Darran, I used my 650 L tank this morning and it took a hour or so and the lot was almost gone, had to take a break and get a hose going into tank,

As a second tank, how many litres does a wheelie bin hold, there is a little 250L tank in my garden  that I could  use and just about squeeeeeeeeeeeeeze in at a push in front of my main tank, if I move some of the 130 metre of high pressure hose, strap it to main tank.

Only concern is would it be any good or to small, obviously would be used when am filling off outside tap 😄

I did a job with a 400l tank and the supply tap was quite slow and ran out of water every half hour

[Smudger]

A wheelie bin is around 200 Ltrs.

That's been the main issue as I've got more work time is wasted waiting for it to fill, and if the mains pressure is low then your out after 20 mins.

Today's job was halved by rolling up and washing straight away.

Last week I had both going for a roof job, we completed it 3 hrs and the lowest the IBC got was 200 Ltrs with the mains feeding the tank so a big buffer tank is a great step forward

Darran

[wpclean]

Similar to use, we turn up to job with 650 litres in tank, and feed customers supply into hozelock fitting on outside of van, and the tank has digital overflow sensor that stop flow when tank is full.    Gives you half hour start not having to wait for tank to fill.

I am defo going to put fitting on bottom for tank for the inlet, instead of putting pipes in top over lid.

[Paul Moss]

Which machine would give better results and also spin a whirlaway best.
15 lpm 4000 psi or 21 lpm 3000 psi