Most vacuum for the money

[sapman]

I need a small vacuum pump for my research bush (<100 taps). Would really like to pull 25"+ to properly test lifting/production methods. Would any cheap dairy pumps work for this, or do I really need a "mainstream" pump, proven to pull high vac?

Thanks,
Tim

[maple maniac65]

most refurbished dairy pumps are not going to pull 25" they were designed to run about 15" to run vacuum for a milking system.

[mikeo]

Design is one thing capability is another! Most dairy pumps are capable of high vac but they were not designed to handle the heat loads that high vac brings with it. You would have to modify the pump through flood oiling and oil cooling to get rid of the heat. The pump needs to be in tip top shape inside and those modifications aren't cheap if you want to set up a reliable system ($400 or more on top of pump rebuild). Breezy Hill can attest to this as well. All said and done you probably aren't going to get away super cheap for 100 taps. If you are spending the money and time to do research you will need something reliable or it can really mess with your results and statistical significance.

Mike

[BreezyHill]

Tim,
As long as you adjust the vacuum controller to the correct settings and the controller is able to be adjusted that far. A dairy pump will work if it is not at a point that there is already to much blow by to achieve 25".
I have a Delaval 75 that I am rebuilding. Finished honing the housing last night. waiting on a bearing and then she will be put together and tested. I will post pics here with the vacuum gauge pics.
I personally wont make blanket statements with out knowing the facts. My experience over my life is that most of the pumps that I have personally seen were not setup in a way that they could reach 25" plus. The ones that were did.
If you are looking for inches for dollars, a used dairy is the answer...but don't just go to a farm looking for a pump and buy it. I can get you one right now that was a 200 cfm pump for $50. It has drawn its last breath. Looks great but inside it has eaten sand used for bedding.
This past week end I picked up two, a D 73 and a Universal M3 both should be fine as the farmer went from buckets to 2" pipeline, then retired. So the 73 was upgraded to the M3. I got it to spin freely; but she will be pulled down and cleaned before I run her as 40 years of moisture has surely put some surface rust on the vanes and housing. This rust will eat at the vanes and reduce the vacuum as the pump is used.

If people went out and just fired up a pump that had sat for any length of time and then it failed; then that was abuse and not the fault of the pump. It would be like buying a used car form a stranger in the next county and then driving it to California and being mad if it gave out. Did you change the oil, grease the chassis, check the tire pressure? No then don't blame the car. I have a couple of boxes of New Surge vacuum weights it is enough to go to 20". You need to put two kits together to get to 22 even 28". Some regulators will only hold 22" of weights. The Surge clear vented housing is just one example of a 22# max control unit. That hanger shaft can only hold that many weights.

Hope this helps.
Ben

[GeneralStark]

It may be worth reading through this thread if you have not already. http://mapletrader.com/community/showthread.php?20908-Small-Pump-for-High-Vacuum

It seems like for less than 100 taps you have some good options for pumps, but the bigger question that cost is how much time do you want to spend screwing around and how important is it to be able to maintain high vacuum during the season? Sure you can modify a dairy pump and probably get it to pull 25" but how much time and energy do you want to spend dealing with it?

If you go with a small 3 phase pump like a 1.5 hp liquid ring, you can run it with a VFD and control the rpms of the pump with a transducer.

How important is this "research bush" and is it worth spending more to get a reliable pump that you don't have to invest time and money into so you know you will be able to achieve high vacuum throughout the season?

[sapman]

Points well taken. I would really rather not screw around trying to make something work. If time wasn't such an issue, I wouldn't mind. But the main bush keeps me plenty busy. Actually, after a couple years on high vac, I might not mind going back down to lower levels. Then I could take the high vac pump to a more productive location I suppose. Might just have to bite the bullet for now to accomplish what I want.

Thanks guys,
Tim

[BreezyHill]

Great point, Reliability is of utmost importance; and yes the world renowned maker of vacuum pumps...Delaval... model 73 & 75 even has on its tag the motor size needed to spin at three different rpms. Thus it would be easy for a person to use a variable speed to run the unit. This is how delaval sets up the new pumps in order to use less power and even longer and higher reliability, than the pumps of the past century that lasted for decades.

When the unit turns on or is turned on it runs at max rpm and slows down when the desired vacuum level is reached. Then the unit loafs along to maintain the desired vacuum level. The slower speed of the pump also reduces the amount of heat generated, thus increasing the reliability and performance of the pump.
Yes it does take a little time...hour or so to make these older pumps really sing. But if you want a bullet proof pump...literally, then you add the drippers to the vac system and get a fan to cool the housing. Yes I do have several designs on oil coolers but I am testing them to see the best for the least amount of $$$. Pretty amazing how Delaval business has stayed around for over 100 years.
The 15" number is misunderstood by many also. This is the amount of vacuum that can be applied to the mammary system of the cow, goat or sheep and not cause cellular damage or pain/discomfort. If you have ever put your finger in a 1.5" section of tubing and applied 28" of vacuum you will not forget it soon. Now think about a rather delicate piece of tissue, a cows teat, under that amount of vacuum, on and off for about 10 minutes. She is not going to let you do that twice and certainly not two or three times a day for 300 days, and again after the next calf for another 300 days. Cows will freely walk into the parlor to be milked.
So yes dairy is LIMITED to 15" for health reasons not design parameters. Oops did I let that secret out?
If a person ever looked inside a gast and a delaval or an Alamo pump they would be surprised to see nearly no difference. Just different vane materials, widths, diameters and some have more or less vanes. The big thing that gast did was to make the pump body like the old GE motors with a fan that blows over the body housing for cooling and having an option of drippers and oil reclaimers. The pumps of the 50's to 80's didn't have that because they didn't need that. Today some of these pumps run 24/7 for years until they crap the bed and the standby unit is turned on and a replacement is installed. I know one farm that gets about 3 years out of a pump milking 24/7 on 1800 cows. Synthetic pump oil and oil changing is the key. These units all it takes to change the oil is open a valve and drain the reclaimer and pour in the new oil. Quick and easy.

If you do have a money tree... can I get a grafting off of it. :lol:

[sapman]

That is a good point about using a vfd with a dairy pump! I've been running a vfd with a Busch, and love it. Surely it wouldn't take much to maintain decent vacuum in 100 taps, assuming I'm keeping on top of leaks (which should take all of about 10 minutes to check). I've been planning on doing variable speed with whatever pump I end up with. Was going to convert my 60 cfm gas unit for the time being (wayyy to much pump, but it could just idle). But it takes a 5 hp electric motor, then a $1600 vfd. Hence, I'm looking at other options.

BTW, my brother-in-law got rid of his cow, so there's what I think is a Surge sitting in his little barn. Saw it pull 22"~ before. Maybe I should talk to him!

[sapman]

Just found a new 2567 Gast online, oilless, around $800. Says 1.1 cfm at 25". Sounds like a decent fit for me, maybe.

[jrgagne99]

For <100 taps, I strongly recommend a $100 A/C evac vacuum pump. You get them on ebay or amazon 1/6 hp. I've run mine for three years with excellent results. I pull 26 inHg with my homemade releasor. There's a thread on it somewhere on mapletrader if you search for it.

[BreezyHill]

Tim, Certainly talk to your brother. Is the surge a rotary or a piston unit? Both are good units while the rotary will take a vfd better than a piston unit as the speed of the crank shaft splashes oil on the interior of the pump body for cooling. Do strip down the pump prior to running it. Found a mouse nest in the last one I rebuilt. It would have destroyed it in a few hours of running with all the fiber glass insulation and seeds in the pumps oil reservoir and exhaust portings. There was a little insulation pushed into the main housing that would have scratched the vanes and housing negatively affecting the future of the pump. She is back together and waiting on vacuum oil delivery so that I can get her on the bench and test her. The test includes a cfm test at 20,25, & 28 inches cold and then after she hits 120 degrees I retest the cfms and then run her for 8 hours at 28 and record the temp to watch for bearing issues and unusual vane activity or any vane clicking and a final test of cfms.
The clicking is from a vane sticking and not maintaining contact with the housing. This is very bad for the housing and will lead to premature failure of the pump. You can check the vanes in a pump by turning it backwards by hand and listen for the vane dropping out of the rotor/ drum as it turns to a point that gravity will pull the vane to the housing wall. A click is a metal vane and a thud is a non metal vane. Metal has a much longer life but the use of incorrect oils will shorten the pump life. Vacuum pump oil is designed to vaporize off at lower temps for better cooling. The vaporized oil hits the oil reclaimer and is condensated to complete the releasing of the heat. Then it is sent back to the pump to restart the cooling process. The non metal vanes hold heat and have more friction on the housing and will shine the housing better than a metal vane. They both have their advantages and draw backs. Quality oil makes all the difference in the world. It isn't cheap but it beats having a pump that lasts vs one that fails part way into the season.

I am also working on finishing a new reclaimer design. Came across an old dairy designed one that is really simple but expensive to build and weights to much. So I am using the principals of design in some recycled materials of today. Should ne finished in a couple of weeks. that is if the boys soccer doesn't make it past sectionals. Another run to state finals will really take a chunk out of the schedule again.
Let me know one that surge if you need some pointers.

Ben

[sapman]

Hi Ben,
only thing with that pump is I doubt it will go much over 22",from what I've seen. I don't know, maybe a little a /c pump WOULD work for me? I don't suppose they make hardly any cfm.

Thanks,
Tim

[BreezyHill]

Did you isolate the pump from the vac controller? If not then you are looking at the maximum amount that the vac control unit will allow. This is typically 22" unless two weight kits are used in one controller and there is room for them in the unit. The older units were more adjustable than the current units. The only issue I see with an ac unit is it is designed to run in an oil bath. This can be duplicated by using that type of oil in a flood system and watch the temp. I used one of these to power a set of air horns when I was in the squad. Worked for a few years then seized up. But they are cheap and easy enough to setup.