Pond Boss Forums AERATION Systems questions Free aerator...Yippee!!!

OK...turns out we use a vacuum system in our dealer shops to check the integrity of...one of our products. We supply to the dealer a small, wall-mounted cabinet with lights, dials and controls already built-in.

They system uses a Gast Model 0523-507-G18DX pump...and they gave me one. I need to put on a new cord, replumb to output from vacuum and voila...I now have a compressor to aerate my pond with next year.

Can anyone give me any info on output for this unit? I know nothing about it other than it's 110 V, and it's free...you'd think our own tech folks could tell me this stuff. However, they say "...uh, we just order it and put it in a cabinet..."

Any help will be greatly appreciated.

MODEL 0523 SERIES
26" HG MAX. VAC., 4.5 CFM OPEN FLOW
10 PSI MAX. PRESSURE, 4.5 CFM OPEN FLOW

From http://www.gastmfg.com

Be aware, rotary vane compressors will require new vanes, Repair kit K478 (0323/0523), about every year.

But, you CAN'T beat the price you paid!!!!

Thanks Rainman.

How much for the vane kit? Thinking of replacing it over the winter before I even put it in place. Yeah...price was right, and it even WORKS!

Now I gotta start rounding up the diffuser and airline to go with it. Need about 350 feet to get it to the pole shed for power, maybe another 50 feet or so for in the water.

I looked at a table that gave me those same numbers. If I'm reading it correctly, it's saying 10PSI max, and 4.5 cfm at 0 PSI...tails off a bit to something like 3.2 CFM at 10 PSI???

How deep ya spose that'll push the air? I need approximately 15-17 feet to get to the deepest spot...50 feet closer, maybe 13 feet deep.

I'm not sure on the depth to pressure thing Matt, but I seem to recall something like 3 feet per psi......

I used 1000' of 1/2 black plastic tubing and used steel fence posts every 10' as weight in the water. You can zip-tie or use electrical tape to attach the posts to the tubing. I got my diffusers from Diffuser express, but Ted Lea has a nice vertex setuo worth the money.

Since you have a 10 psi max AND the vanes wear out very quickly with pressure, you may want to increase your tubing size to 1 inch or bigger to reduce pressure loss from friction. Call Ted Lea about repair parts, I'm sure he can get them and has a price plus he's a helluva nice guy with a lot of knowledge nd willing to share it with us PB'rs.

That's what I'll do, then. Thank you kindly sir.

Matt and Rainman. The equation for PSI/depth is 0.433PSI/ft. If you want to find out the maximum depth divide maximum pressure by the equation. 10/0.433 = 23.25 ft. At 17 feet we simply multiply 17*0.433 = 7.31. Keep in mind that some diffusers require back pressure to open and this adds to the pressure requirement. Furthermore, I would not recommend continuously running any pump at its maximum pressure.

Matt, I would recommend running 1.5" sch40 PVC from your pump to the lakes edge and then attach the feeder tubing and diffuser. With 1.5" over 350' you will lose about .03 PSI and about another 0.4 for your 50' of 1/2" in the water.

Good Luck

Here's a good resource for friction loss.

http://www.aquatext.com/tables/frict-air.htm

Thanks for the clarification WW! I simply could not remember the depth to PSI ratio.

I actually found that number pretty easily (Google) shortly after I asked the question. Thanks.

I'm thinking 1.5" black plastic from the barn to the pond, as I can use the BIL's vibra-plow to install it easily. It's also (I think) much cheaper than PVC...I'll check today at Menards. 1.5" is $154 for 250', online...pretty cheap.

Hey that friction loss site is pretty cool. If I'm reading correctly, I could step down to 1" pipe, lose .18 psi for 300 feet, added to the .34 for the 50' of 1/2" and still have about 6.7 psi at the diffuser. Correct?

If so, that's where I'm headed...appreciate all the help.

Matt,go ahead and rebuild it,then ship it to me and I'll hook it up and test it on my pond next summer to make sure you dont have any problems
Also,ask Ted about selfsinking hose.Its kinda pricey but I think its well worth it.

Matt, I agree with Tom. Send him the pump to test and deliver the BIL's vibra-plow to me for a 1500' test run.

You just don't seem qualified to do these extremely delicate operations without having your equipment PROPERLY field tested!!!!

Honestly, we're just trying to look out for you and save you from yourself!

I KNEW I could always count on the folks around here to take care of me. Therefore, the pump and the vibra plow are both in the mail along with the checks for the consulting fees I owe the both of you guys...

I dont know about Rainman,but personally,I prefer cash

GREEN IS GOOOOOD!!!!!!!!

Just to chime in with my experience, I have a Thomas vane pump about that same size and it runs 8 hours a day at 10 psi and the vanes have lasted 7.5 years so far. That translates to 2.5 years if run continuous. I have a spare set of vanes for when the time comes and they cost about $100. Given the design of these things I expect that when they go there will be no warning. Can anyone tell me if that's true?

bz, You are a very lucky man! IIRC, Specs show the vanes should last about 4 months at 10psi.

Vanes typically last for 2-3 years and Ive had them last up to 5 years of continous running. Seems the lower the back pressure the longer they last.Vane plates (4 of them) will wear down until they snap off and fall into the lower part of the impeller cavity and then pressure drops to zero.They may also break off and jam the motor until the thermal overload kicks it off.When replacing vanes if the impeller side bearing is getting worn the impeller "end plate" may be scoured and will prevent full cfm output.Also be sure the chamber around the impeller is align to spec as they are adjustable. A simple test once you replace vanes is to restart and close the exhaust valves down and see if you can hold the maximum rated pressure which is usually 10 or 15 psi.The vanes are also directional as they are beveled on one end so be sure to put them back in correctly as is a common mistake to put in backwords or upside down, this can destroy them on restart.

Ted, thanks for sharing your expertise!

When you say the vanes typically last 2-3 years, is that at max pressure? I knew they could last that long or longer a half the rated max, but I tought max pressure increased wear around 4-500%.

I cant remember a 10 psi rated pump that ran at 10 psi that didnt get at least 18 months on it. Im sure there are some out there however as there are thousands of these pumps in service. At 3-5 psi I have 3-5 years as a common replacement interval.Ive have some going 7 years and dont know why they are still running on the original vanes but they are the 1/4 hp model which has a vane about 1/2 the width as the 1 hp model.These pumps are really working hard at full rated psi. In the Gast line the smaller pumps 1/4 hp seem to run for many more hours than the 3/4hp or the 1 hp model. I have also had pumps run 2-3 years with the original set and then the factory replacements run much more and the next set run much fewer hours, Perhaps the carbon makeup varies from vane to vane that I dont know. If one vane breaks it will wipe out the other three.If a 10 psi rated pump is going to operate more than 8 psi I prefer to go to a higher rated model or switch to a piston type compressor.I think vane life also depends on the amount of moisture or humidity that gets into the intake as vane pumps are more sensitive to moisture than pistons. I suggest that if you shut a vane down for more than a month try to run it for a few minutes to reface the vane chamber and heat up and remove any moisture internally as they oxidize very fast when not in use. Perhaps Bill C will ring in as he has been running vanes for many years and has a lot of experience with the Gast line.