Pump choices/compatibility?

gregsfc

New member
I'm what I'd call a semi pro; work for the feds. @ a national fish hatchery. Our crew of five PW'd almost 40 hours last month one man on one machine each time (but not always the same man or the same machine); cleaning 23,600 sq feet of concrete of fish containment units, so it's a big part of our time as part of rearing trout from eggs to 9 inch fish, but PW'ing is not our business but allows us to keep our business running to control algae growth which glogs screens and that could over flow a containment unit and kill fish.

We have two machines, belt driven, Honda GX390s, each fed from a 330-gallon IBC tank as the only water supply; we have no spigot access in our outside fish culture area. The area is about 80 yards wide X 500 yards long; making the use of water hoses impractical as it's another 50 yards to the nearest spigot near our hatchery building. Also, we get our city water given to us from another agency and so we can't start using it for PWing, as that would require a new property contract. We have each tank and machine set up on a separate fork-liftable platform. We have no truck or trailer that can handle that much water weight. The tanks are refilled when they are near empty using a 2 inch line and 80gpm pump that we also use to fill fish-hauling trucks. When we put both machines in operation at the same time, we'll go to different locations in the area, and so that's why each unit is self contained.

Unlike a real pro, I'm very limited on what I can do or try equipment wise or how much time I spend with set up, but I did manage to get our platforms built and now no one can imagine going back to our old set up of taking multiple trips to set up for cleaning.

Now for the question: How do I figure out which pumps would be compatible as a replacement for a Mi-TM JCW-3504-2MHB with an AR RKA4G; it's 3.7 gpm, 3500 psi, 1750 rpm?

I'm trying to decide how high to go with the gpm as a replacement, psi could be as low as 2900, but gpm is not only limited to my 13 hp engine, belt-driven, but also, as a tank of water must last long enough to complete on containment unit, which currently takes about 1 hr., 45 minutes.

Of course, as the gpm goes up, the time will get less, but I'm thinking that if we go above 4.5, we'll likely lose the time gained by going back for a refill, because I'm thinking that, at some point of higher GPM, we'll get less efficient with our water use.

But I'm stuck with looking at all these pumps and can't tell what specs that I need to reference against my current pump.

Alternatively, we could rebuild the current pump, but I'm pretty sure the boss would authorize up to $500 for a new pump that could possibly speed up our work.

This also could be a time to try a turbo tip, but the videos I've seen with their use did not go faster than our current pace. What could speed us up the most is a wider spray pattern with acceptable PSI. We get lots of help with rinsing via continuously running water through our containment units while cleaning and a .5% slope and unlimited recovery issues due to a waste-water treatment system downstream of our work via drain valves. Twenty-five degrees is as wide as we can go with our current 4/4000, w/o having to do alot of re spraying.

Are there turbo tips that'll spray a wider pattern?
 

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Stick a 5.6 gpm legacy or general (Most used pumps probably in the industry) and keep the same nozzles you are using now to keep your gpm at your current level. I would also put the bypass back to the tank when you do this as well, will help with air pockets and better for the pump.
 
Are all the containment areas situated like that? For a simple, close enough formula, you can take the gpm and multiply it by the pressure over 1000. That means a 4 gpm machine at 3500 psi is 14,000 divided by 1000 is a 14 hp gas engine. There are some variables, but that will get you close. It looks like you have a belt drive machine, so the pump will rotate slower than the motor. That means they will also create more suction. That also means that if your machine is operating properly, it will likely be able to use water from the adjacent area.

As for me, I would just rebuild the pump you have. Faster and simpler, and it really is not that hard
 
Hey thanks Benjamin and Scott for the feedback and advice.

To Benjamin...But according to the charts I've seen, if I'm running a higher GPM pump shouldn't I have larger orifice size?

We've got by-pass lines back to the tanks on both units finally for the last five months or so. This has been only a recent upgrade as I had to be slightly insubordinate to get it done. Many months ago, this unit had a relief valve go bad and started leaking. The pump also began cavitating around the same time. I came to this forum and asked and everyone recommended going to a return line. I told the supervisor I wanted to reconfigure it this way. He said "no"; "just put a new relief valve back on it". So I did. It still cavitated.

Then we got a new unit that came with a return line already set up. That was sort of a hassle, because the second unit had no platform system built for it to move everything together, and so every time we moved the unit to the work location and then moved the water tote to the work location separately on a second trip, we had to unroll the return line hose and stick it in the tank. The boss said no to building a new platform. Finally, after several months, on my own time, I built a new platform anyway with the return line set up permanently. Life is good nowadays with the newer unit and the boss says that he didn't think he'd like the platforms but can't imagine now going back to the old way.

Since we still had the cavitation problem with only slightly reduced performance on the older unit, I came to this site and was guided to test for a bad unloader; the unloader tested out bad. I replaced it with an identical unloader that's in our newer unit with the return line, as by now the supervisor understood that a return line is nothing to be scared of and that now he didn't have to worry so much about workers laying the wand down while letting the units run. However, the new unloader did not fix the problem. We've been operating it for months and months with this extra vibration. I'm calling it cavitation, but am not sure. It has not gotten worse, but I'm lobbying to get something done about it.

I'll look in to a 5.6 gpm (Legacy and General) and decide which direction to go.


To Scott...Thanks again for your help. First to address the feasibility of using adjacent water from that containment unit beside the one we're cleaning. The containment units are in pairs just like you can see in the picture, but the next line in the serial of pairs do not have the blue columns at the head which supply fresh lake water; rather the reuse water from the containment units above just flow over dam boards and through to a second pair of containment units. Then after that group of 4, there is a break with pavement betwee. The flow-through (reuse) water goes through 12" pipes under pavement to the next group of 4, which also has fresh water via the blue columns. There are 4 groups of 4 in serial for a total of 16 containment units and there are two more abreast just like these. If all the containment units were the same size, we'd have 96 total, but we have sixteen nursery raceways at the top for a total of 104 containment units. We have a flow-through system, so all the water coming in flows through our system gravity fed, straight to our discharge, which creates a creek or stream. But each containment unit has a valve we can open with 12" pipe under ground. We open them for weekly cleaning when they have fish in them and periodic pressure washing when they're empty and we're ready to put fish in them. The water flowing through the valves, instead of over dam boards, goes to a drum-filter-type waste water pollution abatement system. This is why recovery is not an issue. When we pressure wash, we stop most but not all the flow through the containment unit, because a little flow helps rinse, as the algae can be very thick on the floor. With no extra flow, this thick stuff will cause the water to back up and we can't see what we're cleaning.

Here's a link to a picture showing most of a group of 4. Imagine 4 more groups just like it in serial and then two more abreast beside that group of 4.

http://dalehollowhorizon.com/volunteers-help-make-fish-hatchery-programs-successful/

We're using lake water to fill our totes. We use a 50 mesh filter at the pump to fill the totes as a pre filter. This water comes from the reservoir, 95 feet average depth and through 1/2" screens and then a through six inch pipes and the packed columns, which have plastic filter media. All of this pretty much keeps the big stuff out of our containment units.

The issue with using the lake water form other containment units is that it is nasty with uneaten waste feed, feces, and algae from the containment units above. If we had spigots on those six inch pipes coming out of the ground then we could have some sort of prefilter near our totes and just set up similar to most professionals with smaller totes and mobile platforms that could be rolled or forklifted. But we'd need a major gov't contract that would cost double or triple what it would cost in the free market.

We've got a sister hatchery one hour away in KY with a person that can help us with a rebuild. That's probably what we're going to do. I'm just always looking for ways to go faster as pressure washing is just a means to end for us.
 
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