Need help with compressor ID

[CGT80]

LeRoi Dresser 2AVC Restore, some questions

Update in post 8: I bought this compressor and have been cleaning it up.


Update: I found the tag on the pump and it is a 2AVC

The parts sources I have found, list the 400 and 2AVC together. The spec sheet linked in this thread lists the 400 but not the 2AVC.

Is anyone familiar with the 2AVC and do you know the difference between it and a 400 series? Do the parts interchange throughout the pump? Are the cfm, rpm, and hp ratings the same as well?


My neighbor has more than a handful of used air compressors. There is one that he had on one of his buildings, but switched it out for another to see which one puts out more air. He may be willing to part with one of them and I was curious to see if this one would be worth having.

It looks like a 2 stage, has a 5hp single phase Baldor motor and a tank from the 70's (I'm not sure if I would run that tank). The number comes up as a Dresser compressor case, but I can't seem to find details on it.

Does anyone know anything about this pump? Specs, links to more info, or info on parts availability would be great. If parts are not available, then it isn't worth a lot since there is no telling how long it will live before it becomes a paper weight.

 

[CGT80]

This pump matches a pic of a leroi dresser 400 series that I have found on garage journal. The pic is of a green pump and these both have a smooth case on the high pressure side, where most of the 400 series pics have an oil plug on the high pressure side of the case.

The name plate must be on the low pressure side of the case, and I didn't look close enough on that side to see it, if it is there.

It appears that there is a rebuild kit available for $270, if it matches this pump. I found a chart for the dresser pumps and this one might be rated up to 23 cfm, if it is the 400. That is actually the size compressor I was looking for........20+ cfm and 5 or 7.5 true HP.

Some people said the quality of the dresser was up there with Salor Beall and others said it isn't nearly as common of a pump as quincy.

Hopefully some of the other dresser owners can steer me in the right direction, and maybe I will get back to the neighbor's place and look for the tag on the pump.

 

[FTG-05]

CGT, is this the chart you found? See attached .pdf.

If not, please post it.

Thanks,

 

[CGT80]

CGT, is this the chart you found? See attached .pdf.

If not, please post it.

Thanks,

Yes, that is the one.

It appears that 23 cfm may be pump or free cfm, as there is a lower rating of about 19 cfm in a column to the right.

The unit is assembled, so I can't measure the pistons, but I could go back and check the exterior dimensions. If I find a tag, that will be better.

Once I know if there are parts available and that it runs well, I will need to figure out how much I should offer him or be willing to pay, should he turn loose of it.

Thanks for the help.

 

[CGT80]

I updated the original post and title. The pump is a 2AVC. Is the 2AVC identical to the 400 series for parts, cfm, rpm, and hp? Why two different names?

The motor is a baldor 5hp with a name plate amperage of 28.5.
The full load efficiency looks like it might say 74% and the PF 76%. The tag is hard to get to for a photo and is weathered. Do these numbers look right for a good 5hp motor? The newer motors seem to have PF rating so something like 1.15, IIRC. Now that I put the pic on a bigger screen, I see the 1.15 service factor I was expecting. It appears to be quality motor.

 

[jallyn]

You are right about the nameplate reading 74% efficiency and 76% power factor. If I run those numbers assuming 240 volts I get 5.2 HP...close enough to 5.0 HP. For a single phase AC motor:

HP = (Volts x Amps x Power_Factor x Efficiency) / 746

and FYI Power Factor cannot be more than 100%. Service Factor, if listed, will be over 1.0 and lets you know how much you can load the motor above nameplate without overheating the windings. In your case with 1.15 service factor you can run the motor at 28.5 x 1.15 = 32.8 amps without worry of damaging the motor. Of course the actual motor amps depends on the compressor connected to it and what speed you are operating it, i.e. what sheave sizes are being used.

 

[CGT80]

That makes sense. Thanks for giving me a refresher on that, I forgot about multiplying the amp rating and service factor, and I didn't know the HP forumla. I used to do electrical work and trouble shooting as part of my construction career, so I am used to working with the wiring, but have not dealt a lot with motor specs. It will be easy to check the actual amperage with my clamp on meter, if/when I run it to make sure the motor isn't overloaded.

 

[CGT80]

One of the old craftsman portable 4hp 25 gallon that we have been using has had better days. It won't keep up with the plasma table, so I had to drag the 5hp 25 gallon cman to that shop and that left me with only the PC suitcase style that I used for drywall work and nail guns/ mobile work.


It took a couple days of haggling to get my neighbor to turn loose of that old LeRoi. We moved it and got power to it, and he decided he thought it was better than the other one he had on his garage, even though this one sat in a back lot for many years. He has many air compressors. After researching the Leroi and hearing they are good units, I was kind of set on this one. 5hp was the minimum size I was looking for and horizontal is a great configuration for me. The rebuild kits are available and not cheap, but better than other brands I have heard about. He wanted me to take his 3hp Champion, but I tried to convince him to get his giant Quincy going. It is about 30" tall and makes a 325 pump look like a toy........which he also has.

Does anyone have a schematic, repair manual, or user manual for a 2avc or 400 leroi?

How do you guys get the valve caps off the machine?

LP side is a bit over 2.5" hex, from what I recall, and HP side has a smaller hex and one with only two flats. It doesn't appear a standard big socket would quite fit without opening it up. I could attempt to CNC plasma cut a socket or wrench from some plate steel.

It seems to be turning slow right now. 575-650 rpm, depending on where you measure the pulleys. The chart I got from this forum shows it should be 800 rpm for a 5hp motor. It is only pulling 24.5 amps at max when it gets up to 140 psi. I am debating on how much pressure I want to run. 140 or 150 would likely do well for me and leave plenty of reserve. There is no pressure safety valve on the tank, so I need to pick a pressure and get one on there that can handle at least 20cfm, asap. The pump pulley is 17.5" OD and is roughly 16.5" at the bottom of the grooves. The motor is 6.75 OD and roughly 5.5 at the bottom of the grooves. 1725 is the motor rpm. The pump pulley appears to use an "A" v belt and the grooves are just a hair under 1/2" at the top, but bigger than 3/8".

Tonight, I cleaned up the pressure valve on the end of the oil pump and verified that it works and that the intake valves open when air is applied. I need to T the intake valves to the top port on the oil pump, as it wasn't done right before, and the center port is to the pump side of the check valve, not the tank side. It seems it should be direct to the tank.

The pressure release safety on the HP intake was nasty and was not set to 70psi, as it said to do on the brass body. I cleaned it up and stuck it on an air hose and adjusted to it goes off at 70 psi.

There was an old amflo pressure gauge in my drawer, that I had on my tig cooler water line, so I plumbed it into the oil pump port. It shows 25 psi when running but it pulsated. The gauge probably isn't great quality and I don't know if it is supposed to be used with oil. It did read air pressure just fine when I tested it, just after getting it out of the drawer. The oil is old but not too bad looking. My neighbor added some motor oil when we tested it out. Can anyone tell me what type and weight of oil would be ideal for this compressor?

I need to get the motor pulley off and see if I can use the bushing for a new pulley, or if I need to just order a matching bushing for a new pulley. Here are the two pulleys I am looking at: One is 8.25 OD and the other 8.75 OD.
http://www.amazon.com/dp/B007YLTNTM/?tag=atomicindus08-20
http://www.amazon.com/dp/B007YLTNTM/?tag=atomicindus08-20

I would like to check out the valves at minimum, but considered pulling the pump apart to bead blast and paint it. There are a number of layers of old paint on it, and some surface rust. I am tempted to just put a rebuild kit in it, if I am going to open it anyway.

Hopefully this machine has plenty of years left in it. It seems like it should do well for me and I love that it is much quieter than the cmans and the sanborn 3hp unit that broke a rod and all made a horrible racket. Speeding it up will make it a bit louder, I am sure, but I need to run a small blast cabinet without stopping all the time.

Any advice would be appreciated, Thanks.

 

[md21722]

Looks like a nice restorable unit. Safety blow off valve generally relates to pressure, not CFM. 30 weight for cooler climates and 40 weight for warmer climates is a good rule of thumb. OD 6.75/17.5*1725= 675 RPM which doesn't seem bad for a pump this size. I would let it run and measure how long it takes to pump up the tank. Generally higher pressure = lower speed/CFM but not usually until you get past 175 on a dual stage. Old tanks were made thicker than today's tanks but that doesn't mean they are free from rust. I would pull the inlet to the tank and look for lots of rust so you can decide on a complete plan for this thing. Horizontal tanks usually rust down the bottom middle if they aren't drained regularly. Some are good, and some are not. Usually if its been sitting and you get any rust out of the tank drain, or anything other than clear liquid, its probably due for replacement. I have scrapped more than one used tank for rust. As far as the motor using a lot of amps, older motors were less efficient but often tolerated more abuse. A top of the line efficient 5HP single phase motor today from Baldor would use 19.1 amps (nameplate).

 

[CGT80]

So far, I didn't get any water out of the tank. I need to tip it a bit, but I did let air run out of the drain. I have been spraying the large plugs on the side, so I can hopefully open them and inspect the tank.

The pop off valve has to be able to bleed off air faster than the pump can put it into the tank. I went ahead and ordered a 3/8" 175psi valve. The tank is rated to 200 psi working and I can set the pressure switch lower (where ever I want it). For now, it will be more than enough room to turn up the pressure if I want, but I could install a lower pop off once I figure out what pressure works well.

I have not timed it to see how fast it fills the tank from empty. My neighbor said he saw it fill in around 5 minutes to 140 psi. I should try the blast cabinet tomorrow and see if it can keep up at the current speed. It is a nice slow chug right now. The motor will support running it faster, since the amperage is below the name plate and service factor.

So far, it seems this is the same as a 400 pump, but that is only based on the rebuild kits which state they fit the 400 and 2avc (this pump). I wonder what the difference is between the two different names.

Wow, 19.1 is pretty low for a 5hp motor. Some of the other baldor 5hp motors that the neighbor had, were a bit lower amperage than mine, but likely newer as well. I need to read up on magnetic starters as well. Many people seem to run them on 5hp motors, but some seem to stick with a simple pressure switch. This motor could pull up to 32.8 amps, based on the service factor, if I change the pulley out.

 

[Wabash]

Give Marcuse and son a call. They were able to email me a copy of the servicing manual and tolerance spec sheet for my LeRoi Dresser 5000 pump. Hopefully they could help you out with information on that particular pump. http://www.marcusecompressor.com

 

[CGT80]

Leroi Dresser restoration/clean up

Give Marcuse and son a call. They were able to email me a copy of the servicing manual and tolerance spec sheet for my LeRoi Dresser 5000 pump. Hopefully they could help you out with information on that particular pump. http://www.marcusecompressor.com

Thanks for the info, I will try that.


Normally, I don't wrench on anything bigger than the SBC in my 79 pickup and 88 K5, or the 1776 vw engine in my dune buggy, so my tools did not include a 2.05 inch socket or wrench. CNC plasma table to the rescue!

A few light taps with a big sledge hammer was enough to get the caps off the low pressure head. There is some oil in the top of the head, but it all looks fairly clean and rust free. There are some visible lines in the cylinder walls, but I wasn't able to feel them to find out if it is anything to worry about.

The HP valves are being a bit harder to get to.

Today, I tried the blast cabinet. I set the compressor to shut off at 160 psi and ran my regulator to 100 psi while using the cabinet. After 5-7 minutes, the pressure dropped to just below 90 while blasting. It looks like a bigger pulley is in order. The compressor might just keep up or maybe even get ahead with more speed. It is only at around 3/4 of the speed where the manufacturer says to run it for the 5hp motor.

The O rings at the oil pump air switch and valve caps could be replaced.

When replacing rod bearings and piston rings, do you guys ball hone the cylinders? Does the gap have to be set on the rings, or are they preset? I wonder how much work I am in for and if it is worth jumping into, or if I should just do the easier stuff and put the other parts on the shelf (from a rebuild kit) and run it as is. Looks like I need to search out some other compressor rebuild threads.

 

[MacMcMacmac]

Re: Leroi Dresser restoration/clean up

Thanks for the info, I will try that.


Normally, I don't wrench on anything bigger than the SBC in my 79 pickup and 88 K5, or the 1776 vw engine in my dune buggy, so my tools did not include a 2.05 inch socket or wrench. CNC plasma table to the rescue!

A few light taps with a big sledge hammer was enough to get the caps off the low pressure head. There is some oil in the top of the head, but it all looks fairly clean and rust free. There are some visible lines in the cylinder walls, but I wasn't able to feel them to find out if it is anything to worry about.

The HP valves are being a bit harder to get to.

Today, I tried the blast cabinet. I set the compressor to shut off at 160 psi and ran my regulator to 100 psi while using the cabinet. After 5-7 minutes, the pressure dropped to just below 90 while blasting. It looks like a bigger pulley is in order. The compressor might just keep up or maybe even get ahead with more speed. It is only at around 3/4 of the speed where the manufacturer says to run it for the 5hp motor.

The O rings at the oil pump air switch and valve caps could be replaced.

When replacing rod bearings and piston rings, do you guys ball hone the cylinders? Does the gap have to be set on the rings, or are they preset? I wonder how much work I am in for and if it is worth jumping into, or if I should just do the easier stuff and put the other parts on the shelf (from a rebuild kit) and run it as is. Looks like I need to search out some other compressor rebuild threads.

2AVC sounds like an old Westinghouse designation, which is not surprising since these were all originally Westinghouse compressors. Those valves look super clean. I wouldn't bother with new rings, the piston crowns look pretty clean. If it was me, I'd just re-pulley it and run it after cleaning it up and fixing any oil leaks. Congrats on buying one of the best compressors ever built.

 

[CGT80]

I installed a bigger pulley on the motor. It should be at 800 rpm, now, and it is pulling 30.0 amps at 150 psi. The name plate is 28.5 with a 1.15 service factor so 32.8 is max amperage.

An online calculator shows it putting out 20 cfm.

0-100 psi on an 80 gallon tank is 3.5 minutes
0-125 psi 4.5 min
0-150 psi 5.5 min

115 (cut in) to 150psi (cut out) is 60 seconds. It will pump 175 with no sweat, but 150 should be plenty.

I installed a 175 psi pressure safety valve on the tank and plumbed the unloader circuit. Also, I pulled the pressure switch apart and cleaned it up, along with the contacts, and painted the housing. I will look for a magnetic starter, since the motor doesn't have a reset switch on it.

Next is to build a belt guard so none of the animals can get caught up in it, and then probably a gasket or rebuild kit and a paint job. The inside of the tank was dry and didn't have any flakes of scale or rust, but has surface rust. I have yet to try to open one of the 2" plugs on the side of the tank. I was thinking about using water and a grease gun to pressure test the tank to it's working limit of 200 psi, and I will run the pressure as low as I can, as long as I get the performance I need.

Does anyone have any links handy to diy hydro testing? I will do a search as well. Thanks


Look at what I saw before, but didn't even notice until later:

This is a 4AWC, or 800 series Leroi pump with a 20hp three phase motor. After I got my LeRoi, I was browsing photos, from my family's sand blasting shop, of tools I was interested in buying. They are closing the shop and my uncle and cousin will keep enough equipment to do the on site work. They blast rotors and other parts for power plants. Their last job was setup inside a machine shop and the rotor was 8 feet off the ground, and I assume mounted in a lathe. They built a tent around it and blasted all the parts so they could be inspected for cracks. The rotor was spun at too high of an rpm and may have been damaged.

I do my fab work from home and don't have a commercial shop or 3 phase power to run this beast, but it would sure look nice next to my other compressor. This was used to run their smaller blast cabinets. It hasn't been used much since they paid to have it rebuilt, because they usually just start up one of the diesel powered trailer units for blasting, and do most work with a couple hundred pound capacity pressure pot and a half inch blast nozzle.

I didn't buy the compressor and don't know if it was even for sale, but I got a bunch of other stuff, including a couple old USA vices, c clamps, Milwaukee 8" 3/4hp bench grinder, and a bunch of other small goodies. I think I got off easy, price wise, since I am family.........but that should all go in another thread.