Mike,
Not to be critical in any way. But if you look at the above link, 90 psi on a
flojet will pump nearly 5.5 gpm. I'm wondering if your not getting confused with the chart above the GPM? It gives SCFM of air at a specific pressure. At 40 psi to the
flojet, you'll get over 4 gpm flow. I run about 25 oz's per minute of FB soap to each of my bays. Not even a gallon a minute if all 4 bays are using FB at the same time. IMHO, 90 psi is overkill and will likey shorten the life of a
flojet. Are you running needle valves?
2Biz,
To me the bottom graph curve with its intercepting graph lines is pretty straightforward ... & I agree that there is only 1-2 GPM gain by running at 90 PSI over 40 PSI. Hopefully, I have not overlooked anything pertinent. I did not pay attention to the SCFM because I knew that either of our 2 air compressors (1 backup) had more than enough SCFM as long as the in line air regulator & Asco solenoid valve etc. did not lower the SCFM too much. The following link is interesting & somewhat related if SCFM was a concern:
http://cr4.globalspec.com/thread/30062/Flow-coefficient-Cv-to-SCFM
Just to make it clear ... as far as I am concerned it is great to hear honest constructive criticism done in good faith. Your point about running with plenty of liquid pumped from your experience for your 4 bay based on your experience makes sense. Remember we have 6 bays. I wonder if anybody has tested a single
Flojet with 8 bays or more. If I would have had significant problems in the over 10 years of using them ... I would be all over trying to tweak the pressure downward. The fact that we tweaked our adjustable volume solenoids on the manifolds probably took care of the possible excess. No needle valves are being used unless those adjustable screws on the banks of solenoids qualify.
I tend to go with the
Flojet Factory's documentation of the need to keep the air dry &/or temperature of the liquid lower than 120° F &/or proven compatible liquid for the specific seals when it comes to longer pump life. Ideally, we would have kept a log of how much the
Flojet was used & of every time a
Flojet went down so we could compare in the event we ran with lower operating PSI. We were really thankful that the
Flojets were light years ahead of the Aro Pumps we used previously. One thing that was just as reliable is when Dakotal Equipment set up a foam brush system (early 80s) a 430
Cat Pump at low pressure ... but that took up a lot more precious ER space then the
Flojet. In fact we left that specific system in place even when we had Specialty Equipment of Mpls-St. Paul come in with their brand new equipment in Sept. of 1987 that included presoak & tire-motor. Because of space needs & the fact the
Flojets take seconds to disconnect made a permanently mounted backup system less practical so we freed up the space.
mike walsh
http://kingkoin.com/USA_Deficit_Reduction.html
