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Ignorance...

Posted by Derek (Derek Bolton), 2 February 2004
Hi

As I am not an engineer I am going to show my ignorance....BIGTIME. Undecided

Some machines seem to have a smaller bore of solution hose than others.
What effect will there be if you replace a larger size bore solution hose with a smaller size. (this is NOT a wind up folks)

Will the pressure at the jets increase?

Will the jet sizes need to be changed?

Is there any increase in strain/stress on the pump?

I know the answers really....just testing Roll Eyes

Derek
Posted by Dynafoam (Dynafoam), 2 February 2004
Higorance Derek?

In a recent posting, either Mike or Ken pointed out that if a TM pump was turned down to 100psi, it would still deliver water better than a standard portable @ 100psi.

The reason for this differential is that the 100psi pumps fitted to standard portables have a much lower flow-rate than the TM equivilent.

The consequence of this is that as soon as the wand triger is opened, and water is pushed through the system, the pressure drops due to the pumps' inability to sustain sufficient flow to maintain that pressure.

Any increase of total restriction such as decrease in bore-size of hose or reduction in jet size will enable the pump to maintain pressure at the expence of the ammount of water delivered to the carpet.

The overall balance the designer considers is between this amount of water delivered and the 'Blast' effect of that water.

The above is a simplification but should give you the idea.

So increasing the bore size would tend to give a LOWER pressure at the jets, unless you fit smaller jets, which would tend to get you back to where you started Sad

generally the effect on the pump strain would be un-noticeable.

John.
Posted by lee_gundry (lee_gundry), 2 February 2004
you would also get a drop in water temp, in a smaller bore hose.

Lee G
Posted by rob_s (rob_s), 2 February 2004
hIi Derek
        In my opinion I think all three scenario would happen.



     rob -s
Posted by Dave_Lee (Dave_Lee), 2 February 2004
Derek,
I may be wrong, but I dont think there would be any difference apart from Lee's point of a slight temp drop.
We are only talking about maybe up 30 % difference in bore size? There would be a slightly longer pressure build up in the larger bore, but once reached, using the same size jet - the flow would surely be the same? Refering to Mikes point about a TM pump - isnt this because, to set it Down to 100psi makes it more reliable than a portable electric pump running flat out to reach the same 100 psi?
Dave.
Posted by Dynafoam (Dynafoam), 2 February 2004
Dave,

I think you have missed the point about the diference between the pumps - a Flowjet 100psi pump can deliver (open flow) a maximum of about 1.67 gpm, whereas a typical TM pump can deliver 3 gpm.

The higher flowrate capability of the TM pump set to 100psi means that in use it actually does maintain that presure.

The Flowjet pump, however will only deliver about 70-80psi IN USE.

I was not expressing an oppinion but quoting test results.

John.
Posted by Dave_Lee (Dave_Lee), 3 February 2004
John,
No I didnt miss the point. What you have just pointed out is exactly what I was getting at - but put another way.
Dave.
Posted by Ultraclean_Systems (Dave Ingram), 3 February 2004
Derrick in a nutshell when you increase the diameter of your solution hose you will increase your water flow. This is what Simon had to do to run 2 RXS from one outlet on his machine. The first 100 had a 3/8 bore and then branched off to two bore hoses this enabled us to run the two RXs with adequate water flow. Lee is right in saying by using a smaller bore the water will loose tempiture buy the time it reaches the end of the hose, spray tips play little part in the equation only if using more than one!
On a portable machine with the small amount of flow and pressure it would not be adviseable to use hose with a bore of more than 1/4"


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