General Pump TSF2421

N

NJWashingGuy

New member
The spec sheet says it will do the following:
1. 12 gpm @ 2500 psi spinning at 1750 rpm
2. 10 gpm @ 3000 psi spinning at 1450rpm

If the following is correct, can I sping the pump at a lower rpm to produce approximately 8 gpm. If I figure correctly for every 145 or 150 rpm gets 1 gallon of water.... so If I spin it at @1200 rpm, will it do 8 gpm at 3000 psi?


Also, what is the mathematical formula for figuring out the pulley ratios. If I had a 3.75 inch pulley on the engine and wanted 1200 pump rpm, what size pulley would I need?

Thanks for the help is anyone knows......I was never a great math student.
Mike.
 
The formula is:
Engine pulley X engine speed = pump pulley X pump speed
3.75 X 3400 = ? X 1200
(3.75 X 3400) / 1200 = ?
12750 / 1200 =?
10.625 = ?


Also, finding proper rpm for flow:
rpm / gpm = ?rpm / 8
(1750 / 12) X 8 = ?
1166.6666 =?
 
NJWashingGuy said:
Thanks Russ, your the man!!
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Mike,
You can run the motors at a lower rpm. We do it all the time. If you are just soft washing this works great.
 
innovativewash said:
Mike,
You can run the motors at a lower rpm. We do it all the time. If you are just soft washing this works great.
Click to expand...

I drive myself crazy every season with "what" to use.... Too many options out there. I was going to spin it at lower rpms to make another 8gpm hot skid. Once you get into the 10 or 12, the benefits are there with the 1/2 inch hose etc and I don't feel like upgrading all of that at this point. If I do in the future, it would only be a belt and pulley change away..... I think......:idea:
 
Quite a bit of difference when you change from the 3/8" hose to 1/2" hose with 8gpm. The hose is heavier but the cleaning speed increase is worth it.
 
Christopher said:
Quite a bit of difference when you change from the 3/8" hose to 1/2" hose with 8gpm. The hose is heavier but the cleaning speed increase is worth it.
Click to expand...

Hey Chris why is that?? I have some 1/2 hose which we like to use on flatwork because it just seems to be a stronger type hose(probably because of the the size difference only) but who says you can't get 8gpm out of a 3/8 hose? I can't remember who told me this and this could be wrong but somewhere I was told that you can get 14+ gpm thru a 3/8" hose no problem.

Does anyone know for sure if that is true and what max GPM can you get thru those 2 hoses?
 
John you just start to lose a lot of pressure and you can tell the difference, plus your machine is using power that is lost in the hose friction. I think 8gpm could go either way but I have found the 1-wire 1/2" hose available now - 3000 psi - is much lighter and easier to work with.

pressure loss chart

http://www.dultmeier.com/pdfs/tech-library/02Water8.pdf
 
There was a large pressure loss when running 300ft of 3/8 hose for me. We were at 2200psi out of a 3500 psi pump with 8gpm and 3/8 hose. When we switched out to 1/2 we picked it back up to about 3300 psi. The difference could be felt and see in the cleaning ability.

were running a tsf2421 on a 24hp and its underpowered big time. We still get about 2200 psi with 250ft of 1/2 hose but im sure its lacking in the gpm a bit
 
Like the guys mentioned, it is about the pressure loss so the cleaning suffers so you are going slower with the surface cleaner or having to re-clean areas or sometimes both.

You can flow a lot through the 3/8" hose but you will lose pressure, typically running 8gpm through a 3/8" pressure hose you will lose about 300psi per 100' of hose where going to 1/2" hose you will only lose about 40psi, that is a big difference.

The 1/2" hose is heavier than the 3/8" hose but for certain jobs like concrete cleaning I will use the 1/2" hose but for softwashing buildings and houses I will use the 3/8" hose since I am lowering the pressure a lot anyway.
 
Russ does'nt it drop the PSI anyway?
 
I have had a few brands (rawhide and some no-names) of the 1 wire 1/2" hose 300 psi, usually for around a buck a foot, and they are not bad at all to handle. They have all lasted as long as any other hose I've had. Here's the latest
 

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tomtucson said:
I have had a few brands (rawhide and some no-names) of the 1 wire 1/2" hose 300 psi, usually for around a buck a foot, and they are not bad at all to handle. They have all lasted as long as any other hose I've had. Here's the latest
Click to expand...

Do they sell that hose in non marking grey??
We stopped using black hoses years ago because when dealing with heat they sometimes leave marks as can the nice color hoses such as the non marking suppossedly-Yellow,Blue and Grey. I find they all mark somewhere at some time but the grey marks were less noticeable so for the last bunch of years I only purchased Grey Powerwashing hoses.
 
Nj Washing guy i have a 12 gpm udor attached to a 30 hp kohlor and at max it puts out 11.5 gpms at 3000 psi maybe a tad lower going through the coil.If you wanted to be sure and get the full 12 gpm maybe the 40hp would be good for you.For the price and the fuel savings i just went with the 30hp which at 1/2 throttle sips fuel.
 
Clean county 14 gpm is a no go through 3/8 about 7 to 8 for 3/8.Thats why some of the larger gpm machines come with 50 foot of 1/2.Tomtuscon where are you getting the 1/2 hose at?
 
Kiloman said:
Nj Washing guy i have a 12 gpm udor attached to a 30 hp kohlor and at max it puts out 11.5 gpms at 3000 psi maybe a tad lower going through the coil.If you wanted to be sure and get the full 12 gpm maybe the 40hp would be good for you.For the price and the fuel savings i just went with the 30hp which at 1/2 throttle sips fuel.
Click to expand...

I had the Udor Penta Series that was rated at 11gpm @4500 psi. I may buy that pump again I know its not going to be cheap. Where did you get your Udor prices from and are they posted some where online?
 
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