Seeking your advice & experience.
We are getting read to buy a power system and a generator. We are mainly looking at both the XRT diesel powered Combi system and the TNT quad pump with a seperate diesel powered generator.
The XRT has a dual stage pump. Does having 2 stages tend to make tool operation slower than a single stage pump? When both stages are operating, does it provide tool operation close to the speed of the TNT quad pump?
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Thread: XRT dual stage pump
11-26-2004, 03:09 PM #1
XRT dual stage pump
11-26-2004, 03:35 PM #2
I'm kinda confused. I believe most HRT pumps are of a dual-stage design. The first stage is higher volume/lower pressure, and the second stage is higher pressure/lower volume.
With this design, tool speed will vary depending on how much force the pump is trying to overcome. I can't recall the exact pressures and gpm's... perhaps someone else on here will, as they're interesting figures.
Some larger systems are capable of maintaining a high volume of flow at their rated operating pressures. This is where you see increased tool speed.
The pumps listed on TNT's site are "Supercharged Hydrostatic 2 stage radial piston pumps."
XRT is also dual-stage... "Patented dual stage continuous duty pump."
All things being equal, speed will be determined by how many gpm's of hydraulic fluid your HRT pump can flow at operating pressure. This has nothing to do with high pressure vs. low pressure systems, or uni/dual/tri/quad tool pumps (though some do suffer when tools are used simultaneously... try before you buy).
Several neighboring agencies have purchased the XRT/Westerbeke combination HRT pump/generators, and as far as I know, they've been happy with them. We demo'd it here prior to spec'ing our rescue pumper. With respect to speed, I found it comparable to a standard portable pump. I can definetly say it did not operate at the speed of Amkus' Ultimate system. I have no experience with the XRT PTO-powered pump, so I can't comment on its performance.
Granted, tool speed might not be the most important benchmark as you consider your options. Like many people here will point out to you, warranty, reliability, service after the sale, loaner tools, accessories... these are probably going to determine your level of satisfaction far more than shaving some seconds off cuts and spreads. And obviously your budget will be the limiting factor.
Last edited by Resq14; 11-26-2004 at 04:00 PM.
11-27-2004, 07:36 PM #3
14,Not to rub salt in a wound but really fast cycle times on HRT isn't the highest thing on my priority list.Neither is a fast winch particularly for HD work.I like to be able to watch the progress and have the control that I get with slightly slower tools.Give a "newbie" or under three year operator your Ultimate system,give me any other tool;I'll bet job for job there will be little if any time difference in a given job.The Ultimate in experienced hands might be a different story.Most of the time speed(cycle time)on a HRT is based on fuild volume pushed not pressure.That being the case it wouldn't matter who's pump system you used provided;that the pumps are equal displacement.Amkus isn't real keen about releasing this info on the system.And I don't have a problem with that.I've used the XRT with several tool systems and found it smooth and reliable.But there is a whole bunch of ways to power tools,it pays to try a few different systems.Happy cutting and wait 'til you see the new "big mouth"Amkus:Sweet! T.C.
11-27-2004, 10:46 PM #4Originally posted by Resq14
these are probably going to determine your level of satisfaction far more than shaving some seconds off cuts and spreads.
Faster tool operation is only one benefit of such a PTO system (when it works as intended). A tech can adjust the speed of tools up and down with our system.
One of the benefits of the XRT/Westerbeke system is that it operates independant of the truck. Of course, that also means another engine system that you will need to maintain. It is a very cool system.
Anyway, the question was about stages and speed. My point was that pretty much all of the pumps being sold are 2 stage, so you can't judge tool speed by this criteria.
Last edited by Resq14; 11-27-2004 at 11:04 PM.
11-28-2004, 05:43 PM #5
To help further confound the issue, the only true way that you can determine the speed of a tool is to compare tools (and power supplies) on equal tasks. While a tool may open and close much faster than the next tool without a load, the performance may change drastically if you put both tools to work on something and then time the opening and closing times.
With that said, I agree with Rescue 101, speed does not always mean a faster evolution. In fact, if you can see a metal tear before it gets too large, you may be able to reposition a spreader and complete your task much faster. It always comes back to technique, experience and having back-up plans for when the initial plan does not accomplish your goal.
Last edited by MetalMedic; 12-01-2004 at 11:54 AM.Richard Nester
Orrville (OH) Fire Dept.
"People don't care what you know... until they know that you care." - Scott Bolleter
11-28-2004, 06:03 PM #6Originally posted by MetalMedic
To help further confound the issue, the only true way that you can determine the speed of a tool is to compare tools (and power supplies) on equal tasks. While a tool may open and close much faster than the next tool without a load, the performance may change drastically if you put both tools to work on something and them time the opening and closing times.
Just showing open/close cycles in mid-air, the pump is in first stage high volume/lower pressure mode, and is obviously going to move faster than when the same pump is in its second stage.
Sidenote: We have and use both, and I'm sold on the performance of the more robust PTO system. No problems with tearing. It's quite the opposite, actually. Rather than dealing with unexpected "pops" and "snaps" as tools slowly build to pressure, tool operation, reaction, and movement is far more predictable.
Last edited by Resq14; 11-28-2004 at 06:09 PM.
11-29-2004, 07:10 AM #7
Does anyone know if the Westerbeke/XRT is tested per NFPA 1936?
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