pressure VS GPM

C

Chris Tharpe

New member
12 gpm @ 2500psi or
10 gpm @ 3000psi,

Which would you choose for flatwork. Its about time to swap out pumps on a machine and its currently powered by 24hp honda so the power levels should be adequate to put out decent performance for either pump. Anyone have either of these 2 pumps on a 24hp Honda and if so whats the verdict?
 
I would go with 12gpm 2500 psi. I run 5.5 gpm @ 2500 psi with 15 deg. nozzles on my rig and can clean concrete just fine with it.
Your runing hot water also, so that helps.

What Pumps are you looking at?
 
pumps were looking at are TSF 2421 and 2221 .

with a tsf 2021 were getting 8.5gpm at 3600psi, when you run 300 ft of 3/8 hose an have the injector inline we get about 2200 at the tip. If we move to 1/2 hose on this machine and run 300ft of it we will loose about 300psi for 300ft or 100psi per 100ft of hose. The larger hose diameter should make up the difference between a 2500 and 3600 psi pump especially if we remove the injector while washing. Something to think about
 
Chris,
I like General pumps in general, NPI. [No Punn Intended]
but check Kit prices before you commit !!
..also, whilst on the subject of "high volume"..
ALWAYS go for the pump with the larger inlet-ports..
that TSF has 3/4" inlets.. that's MUCH better than 1/2" ports for tank-feed,
..and weighing in, at a hefty 40lbs, with 31 oz. oil capacity is good & beefy.
But, if you want to save a hundred bucks..
I also like the XW series pumps by AR..
the XWA-M7g40N is 7 gpm to 4000 psi, with less expensive kits !
..and has the 3/4" inlets.

On a 23-24hp system, we usually sell the full 4000 psi, and 6.7 gpm,
'cuz you can get the performance though a longer hose easier.

..and 6.5gpm is easier to reclaim than more. Eh ?

If you really want over 7gpm..
go dual pumps.. it is too difficult to get reliable seals ANY other way.

Lastly.. ALWAYS dual-feed a "tank-fed pump" of over 5gpm.. with 1" feed lines.
 
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More is better. 12 @ 2500 will beat 10 @3000 hands down through a surface cleaner. Sounds like too much for 24 hp though. Just so happens I have 2 tsf 2421's with about 50 hrs on them in my shed. Nothing like 10+ gpm through the surface cleaner. Jerry you're a wealth of good knowledge but the dual pump thing, no thanks - unless I want 20 gpm maybe.
 
Chris Tharpe said:
pumps were looking at are TSF 2421 and 2221 .

with a tsf 2021 were getting 8.5gpm at 3600psi, when you run 300 ft of 3/8 hose an have the injector inline we get about 2200 at the tip. If we move to 1/2 hose on this machine and run 300ft of it we will loose about 300psi for 300ft or 100psi per 100ft of hose. The larger hose diameter should make up the difference between a 2500 and 3600 psi pump especially if we remove the injector while washing. Something to think about
Click to expand...

I added a 100' section of 1/2'' to try and help the pressure loss situation with 11.2 gpm. It did bring the pressure up alot-around 3100 psi from 2300, but I almost couldnt tell any difference when using a surface cleaner!! IT didn't move any faster or clean any better than it did with 300' of 3/8...I used the 1/2'' once and I don't plan on using it anymore unless it's needed for back up or something!! It was just rediculously too much work trying to handle it!!
 
Chris, take a look at AR XWL41.21N, rated 10.8 @ 3,000. $788.44
 
Jerry Why dual feed a pump bigger than 5gpm. I run 8gpm and feed it with a 1.25"hose. I have never had a problem with it. just wondering why?
 
El Flojo said:
Jerry Why dual feed a pump bigger than 5gpm. I run 8gpm and feed it with a 1.25"hose. I have never had a problem with it. just wondering why?
Click to expand...

Becuase 2 is better then 1...... :rotflmao:
 
On verticle surface more can be better. I have used 10 gallons a minute to clean. I have even used 10,000 psi cold units that you didnt need a burner because friction caused 145 degree water.LOL

I think for horizontal cleaning lower gallons and the right pressure is KEY.

4.5 to 7 is the range. 3500 to 4000 psi is Key.

If your able to use more water without down time I would use high GPM. I would not go below 3500psi ever for horizontal cleaning. ( concrete)

Chris your doing fleets, I would not down stream soap at any higher than 4gpm ever.

I would even consider less, i suppose your chemical guy would give you a larger pump.LOL

This is only my choice over the last 25 years, things change and if the water became more accessable we might go larger.

We have reduced some units in size to save energy on regular maint. We made the entire unit electric and lowered the weight. ( I will not disclose this UNIT) Not ULR approved and might never be.

The unit runs on LP gas also when not availiable to plug in.
 
dual feed large flow pumps

El Flojo said:
Jerry Why dual feed a pump bigger than 5gpm. I run 8gpm and feed it with a 1.25"hose. I have never had a problem with it. just wondering why?
Click to expand...

look at the "smallest opening" the water has to flow through to get inside the pump..
the bigger the opening, the easier the flow..
I've see 1 1/2" feed lines reduced through a 3/8" at the pump inlet.. :bash:

maximize the delivery of water into the pump..
eliminate all but brass fittings, for NO rust-issues,
and avoid plastic hose barbs 'cuz they don't have as "open" a thorofare as a thin brass nipple.

If your 5 to 6 pump has 1/2" inlet threads.. don't expect seals to last more than 6 to 9 months unless you DUAL-FEED it. ...click here for examples !

same math on 7 to 8gpm with 3/4" threads..
dual-feed it for insurance..
fittings are cheap.. seals are NOT.:victory:
 
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Sirocco Jerry said:
look at the "smallest opening" the water has to flow through to get inside the pump..
the bigger the opening, the easier the flow..
I've see 1 1/2" feed lines reduced through a 3/8" at the pump inlet.. :bash:

maximize the delivery of water into the pump..
eliminate all but brass fittings, for NO rust-issues,
and avoid plastic hose barbs 'cuz they don't have as "open" a thorofare as a thin brass nipple.

If your 5 to 6 pump has 1/2" inlet threads.. don't expect seals to last more than 6 to 9 months unless you DUAL-FEED it. ...click here for examples !

same math on 7 to 8gpm with 3/4" threads..
dual-feed it for insurance..
fittings are cheap.. seals are NOT.:victory:
Click to expand...

Get an Udor and don't worry about seals or anything else. If your pump is not cavitating one supply of at least 1 inch will suffice.
 
William, what Udor do you like and what are the specs on it?

Thanks.
 
Meticulously-Plumb your pump !

"Flow restriction through a fitting" was the point in my previous post.
Udors, are good pumps..
I like them for rebuildability, as our service dept. has rebuilt almost every Udor that has come through. But..
Udors still don't have bigger inlet ports for you tank-feed guys.
You need 3/4" inlets for 5 to 7gpm tank fed, and 1" inlets for 8 to 12 gpm..
I am "immovable" on the point,
So, if it has two inlets, feed them both.

You guys deserve longer-term-lower-cost.
..and even if you're "stuck on lables,"
I'm still focused on lower-cost repairs.
I'm not married to any manufacturer..
I just prefer AR for value, and the fantastic customer support.

You still have to meticulously-plumb your pump,
..no matter what brand it is,
..and take really good care of it..
If your system has NO "flow-restrictions,"
the unloader bypasses to the tank,
and has a "maintenance program" including synthetic oils,
it could last much longer, more easily.
Treat opportunity with Faith.


Now, go out to that trailer, and start removing "flow-restrictors"
because it is cheap "insurance."
..Whilst 'yer at it..
dual-feed it for another $15.

The best long-term plan, is cheap insurance. Eh?
 
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Is Udor the only one with the u-packings? I am convinced (by William) they are better, otherwise all the brands seem about the same to me.
 
V-packings vs U-cups for Hi-psi

AR pumps in the larger flows use U-cups,
but here's the "engineering-perspective " on this..
The U-cup design "should" hold a tighter seal between the plungers and pump-head surfaces, but..
the added surface area of the U-cup compared to the V-seal
is theoretically a larger surface area to build up heat..
this is allowing more heat at the seal we don't want to melt-away.
So, V-packings should be better for heat-resistance.
But..
in the service dept., as almost 30 years of test-results stacks up,
I have to say it doesn't seem to be a noiticeable difference
between one seal and the other.
Beside all that,
"How long things can last" is more about how they are treated and maintained, is WAY larger an issue..
That is why I'm a "broken record" on the piont..
It's all about How the mfr. plumbs the pump,
How you connect it to the tank,
filter, hose size, and EVERY little fitting in-between.

Buy BEEFY rods.. Bronze is more resistant to "total melt-down" aka low oil.
Buy Beefy head and bearings.. you get this in a "heavier pump".
Buy seals you can "GET EASILY"..
Less expensive, and more "interchangeable" with other pumps,
means more local guys will stock the part..
Your DOWNTIME costs you the MOST. Eh?
..and buy from the people that help you the most !!
SouthSide Pete,
EnviroSpec Paul,
and all the other guys you call for the "time-consuming" answers..
We need to achieve our goals too.
Respect the tech !!

The more you focus on "Long-Term-Low-Cost",
the more respect you will have for the technical-guys' opinion.
the "tech" is the service-dept. experience on a "comparative" level,
NOT a bean-counters' idea of what he can profit from.
I don't try to "sell" things..
I show you how to buy "smart" ..hopefully.
..it is an analyitical aproach.
 
I just go by how much the pump weighs - the more the better
 
tomtucson said:
I just go by how much the pump weighs - the more the better
Click to expand...

How big around is much more important than how long it is, I've heard.
The old circumference versus length issue.
 
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