compressor tuning if there is such a thing

[bartman27]

Hey all

first off thanks to everyone who helped me straighten out my heads and valve issues - i know know i have a mako KA0-7da 5cfm -compressor - all is working fine but i have two questions

1st - the unit would pump prior to it going into the shop to 4500psi with no issues - under a closed system (no tanks being filled but the system being pressurized, the pressure went up in a very linear fashion - in other words the time it took to go from 2000-3000 seemed to be about the same as when it went from 3500-4500 - After i had the work done (just the heads) the unit will pump to about 4000psi as normal but then take much longer to go from 4000 to 4500 - is it possible that the unit has an adjustment that i dont know about?

2nd - i have changed the oil used in the compressor to chemlube 501, it seems i have to add oil more frequently now, not a large volume but more than before - does anyone have any suggestions as to what oil i should be using in my crankcase - is the loss of oil from the lower end a sign that the my compression (rings) may need repair?, its not going on the floor - i normally store air in my cascade system at 4500 psi and itys a struggle to get it there now

any comments or opinions would be welcomed

thanks
bm-mi

 

[NAM001]

how much oil is in you water sepaerator fluid. and do you have stage discharge gages, if so do they look normalat the 3000 and 4300 areas

 

[CraigAClark]

Compressors will pump faster at lower down stream pressures and slower at higher down stream pressures. As an example, a 10 scfm machine may be pumping 15+ at a down stream pressure of 500 psi and 4-5 scfm at 4300 psi, down stream. The rated out put of a compressor is an average derived from filling a known volume and dividing it by the time it takes to reach the rated pressure for the volume. Bauer uses a vessel rated for 80 cu ft @ 3000, yet they cheat by starting with 500 psi in the vessel. They also do not have the volume of the final separator and filtration added to the machine either.

Regarding your oil issue, how much are we actually talking about?


Craig

 

[bartman27]

Compressors will pump faster at lower down stream pressures and slower at higher down stream pressures. As an example, a 10 scfm machine may be pumping 15+ at a down stream pressure of 500 psi and 4-5 scfm at 4300 psi, down stream. The rated out put of a compressor is an average derived from filling a known volume and dividing it by the time it takes to reach the rated pressure for the volume. Bauer uses a vessel rated for 80 cu ft @ 3000, yet they cheat by starting with 500 psi in the vessel. They also do not have the volume of the final separator and filtration added to the machine either.

Regarding your oil issue, how much are we actually talking about?


Craig

thank you both for getting back to me - ok i would say about 15 mls after a good hour or so of running - its a viscous oil water mixture - in the first large collector - in the final smaller collector only water is released and very little maybe 10 mls if that - it does not run out but comes out in little sprits - is the amount of oil in the collector ( i am sorry i dont know the names of each of them) a measure of how worn the compression rings are?

i am pumping right now and it is filling the 4000 and 4500 psi cascade botttles to 4000 psi but stopping there as it takes to long to get to 4500 - i was thinking ( the first problem) there was a limiting adjustment that may be turned down -- the pump is rated to 5000psi - i caqnt imagine how long it would take to get to that pressure - i am very happyt with the compressor, just trying to learn enough so i can service it myself - (heads and valves) - the shop i use is a good 2 hours away - be perpared i have a ton of dumb questions - there is never any water in the filter cartridge container thanxs bm

 

[Zodiacdiverdave]

Hey Bartman27, as for the low output @ high press. I would first check for any kind of leak around the final stage cyl. head. where the head mates with the cylinder and where the lines come in and go out of the cylinder. Also where the little cap for the valve that is on top of the cylinder. Check for leaks around inter stage and final separator as well as the filter canisters. This can be hard to do when your compressor is running so you must trap the pressure in the compressor when it first shuts down. If you have an auto drain system from MAKO you can do this by moving the small red lever on the solenoid to the up position prior to the unit shutting down , listen for leaks if you feel around for leaks be real careful, the unit will be hot and the high pressure gas escaping can harm you. At this point the pressure should remain in the unit for several minutes but will eventually escape due to very small leaks in the system that are usually present in older machines. Check the relief valves on the stages and on the final separator.
If all you had done prior to this problem starting was a valve job then I would say you will find the leak.
As for the oil you may want to step up to Chemlub 751.

Now I say this every time I post a response to someones questions. Keep us updated on the repair so we and everyone else can learn from this.

Good luck
ZDD

 

[Wookie]

A leaking relief valve, intermediate or final, will present exactly the symptoms you are describing, both the oil use and failure to deliver air. I can't explain why a leaky relief valve results in increased oil use, but I have seen it multiple times. ZDD's procedure with the little red lever will help you figure out which safety valve is bad.

 

[bartman27]

A leaking relief valve, intermediate or final, will present exactly the symptoms you are describing, both the oil use and failure to deliver air. I can't explain why a leaky relief valve results in increased oil use, but I have seen it multiple times. ZDD's procedure with the little red lever will help you figure out which safety valve is bad.

i checked the pressure relief valve on the 1st larger separator - it is a kunkle model 30-A01-KM, size 1/4", set700 psig, cap 146, G01 scfm. it appears to be leaking from the little hole in the valve itself -

i looked up the model online and it says it

Model 30 ASME Section VIII Air/Gas, 'UV', National Board Certified Safety valves Pressure Range: 60 psig to 4000 psig Temperature Range: -20 °F(-28.89°C) to 300 °F(572°C) Features and Benefits: Top guided disc provides optimum performance. Applications: Small to medium size, multi-stage, air compressors, intercoolers, aftercoolers, instrument/control air lines and systems. Air tanks/receivers and pressurized equipment. Question 1 - I routinely bank 4500 psi- does my valve have to low a pressure range Pressure Range: (60 psig to 4000 psig) for be able to do this - my valve is identical but says set 700psig, this makes me think my valve may already have a higher pressure range - the oil seems to be coming out of the hole in the photo - is it possible the valve on my unit is not correct? - i am excited to learn, i just need someone to enlighten me lol - here is a silly question can i clean the valve and have it work correctly? - any help would be great thanxs bm any idea where i can get a replacement online quick would be good also thanxs

 

[Zodiacdiverdave]

Bartman27, congrats on finding the leak. Lawerence Factor sells that unit they also sell smaller less expensive ones that work just as good. Unless your local laws require you to use an ASME valve then I would go for the smaller one.
ZDD

 

[bartman27]

Bartman27, congrats on finding the leak. Lawerence Factor sells that unit they also sell smaller less expensive ones that work just as good. Unless your local laws require you to use an ASME valve then I would go for the smaller one.
ZDD

I already purchased an EXPENSIVE one = being delivered tomorrow afternoon - will let you know how it goes - yeah the old one is leaking from the back end where the pull pin is - maybe from the side as well

thanxs
bm

 

[bartman27]

i already purchased an expensive one = being delivered tomorrow afternoon - will let you know how it goes - yeah the old one is leaking from the back end where the pull pin is - maybe from the side as well

thanxs
bm

the new pressure releif valve is set for 700 psig - is this a normal setting. It seems low even for the second stage - can i go with a high pressure releif valve - again just learning

thanx
bm