Hey guys, I have a few questions about guns, tips, and pumps. My pumps are all cat 5cp2120w. My bays were originally all set up to run 3 gpm. The guns I have been using were giant 21295cx. I recently started replacing some guns with giant 21295c model guns. I have always been using 2505 tips. When I started changing out guns to the newer model I noticed some of my pumps in the equipment started to get very loud, rattling, shaking etc. Is this normal? My understanding is the only difference in the guns are the c models weep less water/at a slower rate than the cx model. Can anyone give me some advice? Am I putting to much pressure on the pumps by limiting the amount of water that's available to come out when the trigger is not pulled?
Guns, Tips, and Pumps
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MEP001
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Does the pump rattle as soon as the trigger is released, or does it take some time? If there's not enough flow to the bay, the pump will get so hot from the pumping friction that the water will boil in the manifold and can melt the plastic. This damage was caused by an employee leaving the washdown switch on overnight:
The sound and rattling is definitely worse when the trigger is pulled. The moment the trigger is pulled is the worst. I initially thought the belt was loose or was about to break but that wasn't the issue. Also, I forgot to mention this earlier. The pressure at the pump is reading almost 1500 psi. All my other pumps are running about 1200. What would cause such a drastic change in pressure? I have made no changes to the pump or the system other than the gun.
MEP001
Well-known member
The change in pressure would be because it's set there. Your old tip was most likely eroded. I don't know what the noise is from, but I'd start by reducing the regulator to 1200 with the trigger pulled and see what it sounds like. Maybe post a video on Youtube with it running.
Damoni88
Active member
the blue hose is connected to the regulator. Also if you increase to a 2506 tip it might help. The water has to go somewhere when being pumped. Another thing is you could have a bad regulator. Check belts for cracks also. Is it pulsating in bay?
I.B. Washincars
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Correct me if I'm wrong, but is all of that plumbing on the right side outlet hanging on a 1/4" nipple?
I.B. Washincars
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What about the bypass water coming back into the manifold from the opposite side of the regular inlet? Will this cause turbulence within the manifold? In my simple mind, it seems that it would be better if both sources of water came in from the same direction. I'm just spitballing, but maybe you were just right on the edge, and these new guns cause a little more water to bypass and have pushed you over.
I checked the belts for cracks everything looks good. The pump did seem to be pulsating. Can anyone tell me how to adjust the regulator? The only way that I see that may be possible to adjust are through 2 tiny holes on each side?
MEP001
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The brass nut around the stem at the top is the adjustment.
MEP001
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I've seen all sorts of plumbing setups. It doesn't seem to matter where the inlet and outlet are for normal operation, but I've noticed on some that if the water comes in one side and the regulator bypass comes in on the other side, the pump will cavitate briefly every time the trigger is pulled and released while the water has to suddenly change flow. I used to put inlet/outlet on one side and the regulator and bypass on the other, which is a bad idea since it causes a lot of turbulence and tends to cause the center seal and valve seats to wash out faster. FWIW, Cat recommends the pump be plumbed in on one side and out the other side for even through-flow.
You're right on both, the flow of water through the pump is a mess, and that plumbing is all hanging from a Dema solenoid coupled down by a 3/8" to 1/4 reducing nipple.
I.B. Washincars
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I was actually talking about the HP at the pump head, which also appears to be hanging on a 3/8 X 1/4 reducing nipple. I definitely see that snapping off at the most inopportune time.
MEP001
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Yes it is, and it will. With all the high-pressure flow going through that, it's going to erode through from inside and just fall off.
MEP001
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I wouldn't say it's wrong, but it's overly complex with some unnecessary parts. There's no reason for there to be a check valve on the outlet of the pump. There's already a check valve at the tank. I think I know why they did that, most likely they had problems with lines blowing off and just added a check valve. Usually (mostly on older systems) there's a solenoid for cold water which acts as a relief valve if the high pressure seeps back through the pump when it stops.
I.B. Washincars
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If I were plumbing the inlet, I would install another fitting and barb at the LH pump inlet, and connect the bypass (smaller blue hose) there. That would get the inlet and bypass water entering the pump in the same direction.
The outlet...well that needs to be thought out a bit. First off, I don't understand why they adapted down to a 1/4" check valve. The outlet is 3/8, the HP hose and other plumbing is 3/8, and they choke it down to 1/4" right at the pump. I'm not sure if the 1/4" valve will restrict flow, but it seems like it would. The major problem with it is that it has a ton of stuff hanging on that little 1/4" nipple. As MEP says, the water will eat away at the inside, the vibration of the pump stand won't help anything, and last but not least, it will eventually get bumped and snap off. I would have to put on my Jethro hat and do some ciphering to figure out how I would want to eliminate that setup.
I.B. Washincars
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MEP, are you sure that's a check valve at the tank? It looks like a Y strainer to me.
Rfreeman
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In the pic you posted which pumps are rattling? 2 (top right) & 3 (bottom left)? I had a similar issue after I changed the regulator and it turned out to be bad regulator. Exchanged it and the pump has been working fine ever since.
MEP001
Well-known member
Yes, you can see the bulge for the pin of the swing gate. Also, every Y strainer I've seen has a hex cap; check valves usually have the square nut.
