Mako Bauer Purus E questions

[dvr6]

Hello I have recently acquired a Mako branded Bauer Purus E. I have read about other purus compressors but have not been able to find anything on just a plain E.. It has a 2 hp electric motor and the nameplate says its rated at 2.5 cfm. . I have used it for air fills to 3200 psi with no problems. Total of 7 tanks so far. I plan to use this compressor for an average of 20 fills per month (1400cuft) personal use.

Few questions--

is the current filter/system pictured adequate for air only fills?

Also I am not sure if the pmv is working. When I start the compressor with no scuba cylinder the pressure starts rising immediately, does not seem to have any delay. Where is the pmv on this compressor? is it the valve to the right of the shroud in the pictures? How is it adjusted?

Any opinions about this compressor as far as how many hours before problems requiring overhaul, etc. Anything to watch for?

 

[windyairman]

Hi
PMV is built in to the top of filter housing [under clear plastic cover]
Valve to right hand side is main relief valve.

Filter system is very old & small
Think that you best upgrade this.

parts & work shop manuals you can find on bauer german site [ bauer Kompressoren]

 

[wwunder]

The valve on the bottom right of the shroud is you relief valve and are not typically intended to be adjusted. There is a port on the front of the relief valve block (currently has a blanking plug) that you could plug a pressure gauge into to check the pressure upstream of the PMV. This way you could open the fill valve to atmosphere and if the pmv is working it would read in the 1500 to 2000 psi range.

I have a purus with a 4 horse briggs gas motor and spoke with people on here and Lawrence factor. That housing is too small for triplex filtration, but Lawrence factor makes a molecular sieve and activated carbon cartridge for it. Based on the numbers I received it would provide about 10 fills of Grade D air per cartridge (in relatively low humidity, cool conditions). The conventional recommendation is to upgrade to a bigger filter can with check valve, PMV etc.

My purus is a project so I haven't done anything with filtration yet, but I lean towards adding a 16" tower with triplex filtration that would reliably produce grade E air and bring the per fill filtration cost down a bit. I'm also considering converting to electric. Can you tell me what the pulley diameter and motor specs are on your machine?

 

[windyairman]

Hi
i have just fitted a old purus up to a 1 phase motor.
our voltage in england is not same as your but this may help
Motor rpm 2800,Full load 12.5 amps,
Pulley on motor SPZ140
Running curent at 250bar 9amps
Compressor 7 Rpm slow with this set up.

Compressor has 153/4" pulley 8 blades

Warning
These pulleys on the compressor are known to have a fault.
Look on the outside just at the point the fan blade joins outed pulley.
Small hair line cracks at every blade .
never seen a pulley crack all the way through but loads with small cracks.
I just get a local guy to weld them up for me.
The change in running tone with small crack is amazing.

 

[dvr6]

I believe my PURUS is configured the way it came from the factory.

Motor 2 hp single phase. I have it rigged for 220 but could probably get away with 110...
Motor rpm 3450
Motor pulley 3"
Compressor pulley either 6" or 6.5"

Data plate on the compressor says 1500 rpm and 2.5 cfm.

If the compressor side pulley is 6" -- rpm's equate to 1725
If the compressor side pulley is 6.5" -- rpm's equate to 1592

 

[wwunder]

I believe my PURUS is configured the way it came from the factory.

Motor 2 hp single phase. I have it rigged for 220 but could probably get away with 110...
Motor rpm 3450
Motor pulley 3"
Compressor pulley either 6" or 6.5"

Data plate on the compressor says 1500 rpm and 2.5 cfm.

If the compressor side pulley is 6" -- rpm's equate to 1725
If the compressor side pulley is 6.5" -- rpm's equate to 1592

Thanks Guys, I was wondering if a 2HP would do it or if I need 3HP. The only other question in my mind is if I could spin it a bit faster with a 3hp and get a bit faster charging rate. I know that frequently these compressors are set up with different motors and different pumping rates, but I'm not sure what the acceptable range is. For instance, my compressor is rated at 2.8 CFM with the briggs motor so it would correlate to an RPM of about 1700. It will likely end up being decided by what motor I can track down first.

Have you had any luck with the PMV?

 

[dvr6]

PMV was not adjusted, it was discharging at the whip from 0 psi. I was able to adjust it but it is very touchy. I Can't get it to hold and then open at 2000 psi. It releases around 300-400 psi creeping up to fully open around 2000 psi (although not reliabily). When I upgrade the filter I'll add a new pmv as we'll.

 

[wwunder]

Hmm... I'm told the bauer components (including PMV's) tend to be very high quality so the leaking part is probably a malfunction. I haven't taken mine apart to check what is involved, but I think it might be worthwhile doing a teardown to clean it up and replace O-rings.

When you upgrade the filter will you replace the coalescer as well or keep the existing filter inline and add an additional chemical filtration stack downstream?

 

[dvr6]

I'm not sure what I want to do at this point. The pmv is working as it should now. It had a stack of washers under the set screw. I replaced them with a heavy spring and it now opens more abruptly at 2500 psi. As far as filtration goes. We'll I'm on the fence. The compressor only puts out 2.5cfm. It is powered by an electric motor and is run in a clean air environment so no carbon monoxide or voc issues. It is run on Synthetic oil. Hmm I've already dove 7 fills with zero issues, and that was with the pmv not working. I may just make sure the pmv is functioning properly and repack the carbon filter that comes with it with 1/4 desiccant and 3/4 carbon every 15 fills or so and call it a day. It's a small filter , filter size is 4 1/2" by 1 1/4" diameter but if I repack often I'm thinking it will be fine. It is very easy to access the filter, just a few minutes.