[chris scott]

 Interpump Ws 251 1450rpm 15lpm 250 bar.  What do you think up the pressure to compensate for lower flow...do you think it equates to same cleaning power as say a ws 202 ?

[Matt Gibson]

I think it depends what your cleaning. Rob wants all this flow because its easier to washdown large areas with a huge flow..

I went from a 201 to a 202 and i noticed a difference even on driveways..

[chris scott]

 I just dont like customers watching me "standing around doing nothing" while the water catches up.
 I would rather keep moving albeit slightly slower!!! Always a compromise .

[Kenny83]

I would go for it if your thinking of buying one... same as the w965 but with a gearbox so the pump will last longer

[BDCS]

Just fit a smaller nozzle and drop the revs to suit

[chris scott]

Just fit a smaller nozzle and drop the revs to suit

Will that work ..terms of reliabilty, unloader  cycling etc The theory is right but a 200 bar pump is just that . It is not design to produce 250 bar

[BDCS]

You will only rev the machine to 200 bar and the unloader would be set at 210. I only ever use a 55 on my 21 ltr m/c unless I'm using the fsc which has two 35's. Pressure is inversely proportional to flow and the revs directly affect the flow. It maybe difficult to comprehend the principle but cheaper than buying a new pump to achieve the same thing. I have turbo's right down to 35 in the van

[chris scott]

So in using the bigger pump i will get the same flow ie 15lpm but at a higher pressure 250 bar. Where as you are "only" achieving 200bar at 15lpm but from a higher flow 21lpm pump? So using 050 or  2x 25*x025 fsc i will produce 15lpm at 250 bar as opposed to 200bar (approx output  figures..045 2x25*x020 would be ideal!!)
Would it not be the flow would be Directly proportional and not Inversely proportional to engine revs ?

[BDCS]

You confuse pressure and flow. Makes no real odds what a pump is rated at. Select your nozzle for the flow @ your 200 bar, set your unloader to 201 bar and the rev the machine until the unloader dumps to tank and back the revs off until the flow to tanks stops - this is with the trigger open. Pressure increases as the flow decreases (inversely proportional) ie stop end gives maximum pressure and open end gives a low pressure. Yes the flow is proportional to the revs in a positive displacent pump - I did say pressure was inversely proportional to flow

http://wiki.answers.com/Q/Is_pressure_is_directly_proportional_or_inversly_proportional_to_flow

[chris scott]

"Inversely proportional" when  there is no flow from the nozzle ie Gun shut off  pressure builds up in the line till the unloader releases it .I do understand about flow and pressure being 2 different things .Flow being the volume and pressure being the force. They taught me all these things on my smartseal/kleeeezee training .   I am struggling to see how  a pump such as a ws202 will give me 250 bar 15lpm working pressure ...but as my girl-fiend says i am a bit of a tard.....(re-tard)

[Blast Away]

"Inversely proportional" when  there is no flow from the nozzle ie Gun shut off  pressure builds up in the line till the unloader releases it .I do understand about flow and pressure being 2 different things .Flow being the volume and pressure being the force. They taught me all these things on my smartseal/kleeeezee training .   I am struggling to see how  a pump such as a ws202 will give me 250 bar 15lpm working pressure ...but as my girl-fiend says i am a bit of a tard.....(re-tard)

Because of the smaller nozzle. 15 lpm being forced through a smaller nozzle will be more pressure.

[BDCS]

Not if the revs are knocked back  Honest

[Kenny83]

Would that work on an 11hp or would you run the risk of stalling it because of the pressure? the engine would be producing its full 11hp if it was at half revs or so? unless you had a decent size engine with plenty of torque?

[BDCS]

 It does work better with a diesel but still works on petrol

[Matt Gibson]

Smaller nozzle on a 21lpm pump would restrict flow, but I too cant see how it could raise the pressure seeing as how the pump only rated to 200bar. I can sort of see that smaller nozzle pushing through theflow would raise psi but wouldnt the excess just dump back? I ran a 05 nozzle on my 21lpm and thegauge never read over 200bar. Even when I wound up the unloader. Am I just being ignorant to facts here? 

[Kenny83]

 if you were to get 21 litres from an o5 nozzle you would have to create 300 bar of pressure, have a look at a nozzle chart matt, you wouldnt get 21 litres mate, it would only produce 16, it's the nozzle that determines the flow and pressure, think what bdcs is saying is that you can get higher pressure but less flow, ie would be good for gum removal etc as he has mentioned before as the water would stay in the bioler longer
 

[Kenny83]

if you were to get 21 litres from an o5 nozzle you would have to create 300 bar of pressure, have a look at a nozzle chart matt, you wouldnt get 21 litres mate, it would only produce 16, it's the nozzle that determines the flow and pressure, think what bdcs is saying is that you can get higher pressure but less flow, ie would be good for gum removal etc as he has mentioned before as the water would stay in the bioler longer
 

Also creating 300 bar of pressure at 21 litres a minute would stall a 11 and 13 horse power petrol engine

[chris scott]

Smaller nozzle on a 21lpm pump would restrict flow, but I too cant see how it could raise the pressure seeing as how the pump only rated to 200bar. I can sort of see that smaller nozzle pushing through theflow would raise psi but wouldnt the excess just dump back? I ran a 05 nozzle on my 21lpm and thegauge never read over 200bar. Even when I wound up the unloader. Am I just being ignorant to facts here? 

My point entirely. If it was possible i feel there would be reliability issues .So any pump whithin reason will do just restrict the flow till we get the desired pressure and hope  the internals of the pump can handle it?  

[chris scott]

Interpump Ws 251 1450rpm 15lpm 250 bar.  What do you think up the pressure to compensate for lower flow...do you think it equates to same cleaning power as say a ws 202 ?

Maybe we are trying to achieve different things here. Have a look at the original post above.

[Matt Gibson]

if you were to get 21 litres from an o5 nozzle you would have to create 300 bar of pressure, have a look at a nozzle chart matt, you wouldnt get 21 litres mate, it would only produce 16, it's the nozzle that determines the flow and pressure, think what bdcs is saying is that you can get higher pressure but less flow, ie would be good for gum removal etc as he has mentioned before as the water would stay in the bioler longer
 

I know that mate. I never said you could get 21lpm from a smaller nozzle. What I was saying is if a pump is rated @ 200bar, even if you put a smaller nozzle on it, it might reduce flow but I cant see how it would raise the pressure by much even if you wound up the unloader cause as you say, the machine would stall. 200bar pump, in my opinion would only ever reach 220, maybe 230bar max whatever nozzle.