Are you going to be putting into one of your 'Mayer' vans on the website, or a separate vehicle?
If using one of your existing vehicles what size tank are you getting because you won't get a large tank in one of those, on top of kit already in there, plus hoses and other pressure washing stuff.
You have been given great advice but what is the vehicle you're working from, what tank do you expect to get in there and what else in that vehicle is 'heavy' kit up against?
Overanalysing PSI against LPM is less important detail, bar pressure and lower flow rate will give you the same end product with less water, possibly.
21LPM is just right for domestic and small commercial but too big to run off a tap (shouldn't be using a direct feed anyway, unless you're getting a yellow Karcher) a buffer tank is required.
Not seen any of this mentioned.
There's probably 750 kilos of kit in the back of my van, then fuel and then water.
If you're taking the machine in and out of the van, by hand, on a ramp, storage for everything?
I tip up on site, doors are flung open, water fill hose (hydrant) attached, HP hose pulled to works and machine switched on, start working away, whether on the ground or elevated, cleaning cladding, whatever - the amount of times people have come up to me, at the back of the van and said, 'any jobs, that looks easy,I could do that'.
It looks easy because of nearly 2 decades of experience, because the set up is nearly perfect and because the kit gives me the best end result.
Clients expect to see dirty & then clean and if done properly it is always impressive, if done badly it looks worse.
The done properly doesn't happen overnight - the shiny machine will not give you the result, the user will.
This is not an easy add on,
Whatever machine you buy there's a bit more than the 'shiny' kit bit.
