Max-Air Systems 90 SFD 6000 Operation manual

High Pressure Breathing Air Compressors
Owner's Operating Manual & Parts List
MAX-AIR • 2807 Peddler Lane • Kerrville, Texas 78028 • USA • 830-257-5006 • FAX [phone]
www.max-air.com [email protected]
Max-Air is a registered trademark with the U.S. patent office –copyright 2009.
This manual cannot be reproduced without the express written permission of Max-Air. Part# MA90'S-07/13
Max-Air 90 SFD 6000 9.0 cfm

Thank you for choosing MAX-AIR, where quality and commitment give you the best in technology and
support available today. Be sure to ask your MAX-AIR dealer about our complete line of compressors
and accessories.
This owner's manual uses signal words recommended by the American National Standards Institute
(see ANSI Z535.4) to designate levels of hazards. These signal words and their definitions are as
follows:
DANGER This warning indicates a very hazardous situation, which, if not avoided, will result in death
or serious injury. This signal word is limited to the most extreme situations.
WARNING indicates a potentially hazardous situation, which if not avoided, could result in death or
serious injury.
CAUTION indicates a potentially hazardous situation, which if not avoided, might result in minor or
moderate injury. It is also used to alert against unsafe practices.
NOTICE
Follow manufacturers recommendations and cautions, of drive engines and electric motors. Carefully
read and follow these instructions prior to operation of your compressor.
CAUTION
As a new owner of a cylinder-filling compressor you are now "a filling station." You must follow all local,
state and federal regulations. Prior to filling a cylinder, check the pressure rating and current hydro date
stamped on cylinder neck. Do not fill out-of-date, (hydro-date) cylinders for anyone. You should also
control that you and your buddies have a valid scuba certification, nationally and/or internationally
accepted and issued by a recognized instructional agency.
GENERAL
In the interest of health and safety, we strongly recommend that you follow these operating instructions
precisely. Damage resulting from any deviation from these operating instructions is excluded from the
warranty and liability of Max-Air.
Special Attention Must Be Paid To The Following:
a) Correct maintenance of the filtering system.
b) Regular drainage of the condensate.
When opening the condensate drain tap, both condensate and air should escape profusely.
Contaminated or wet filters result in contaminated air.
c) Fill "in test" air cylinders only. Normal rated operating pressures must not be exceeded.
d) Air intake.
The intake of exhaust gases (e.g. from the driving motor) could have fatal consequences. When
operating the compressor, ensure that the air intake draws clean air and cannot be contaminated by
noxious exhaust gases.

BREATHING AIR PURIFICATION FILTER CARTRIDGE (DISPOSABLE) Part Number LF-1002 or X302414
Fits only compressor model Max-Air 55 and Max-Air 90 with standard filtration
(Part Number PU-10000)
Typical processing capacity (cartridge life) @ 72oF intake temperature for
Grade “E” breathing air SCUBA or SCBA @ 5000 psi.
Compressor model Max-Air 55 = 10,000 cubic feet (or prox 30 hours of running time)
Compressor model Max-Air 90 = 10,000 cubic feet (or prox 18 hours of running time)
MAKE SURE WHENEVER CHECKING FILTRATION THAT THE
SYSTEM IS SHUT OFF AND COMPLETELY DRAINED OF AIR PRESSURE
NOTE:
1. The cartridge life is based on 72oF intake temperature, draining the
condensate every 15 minutes or more often if in hot and humid climate.
2. The 10,000 cubic feet must be de-rated by 2% for every 1oF above 72oF.
The reverse applies to temperatures below 72oF.
i.e. @ 82oF decrease capacity by 20%
@ 92oF decrease capacity by 40%
@ 102oF decrease capacity by 60%
CARTRIDGE COMPONENT IDENTIFICATION:
A. Sealed foil envelope –makes sure it is not torn or punctured.
Do not open until ready to install. For extended storage re-wrap in two
or three heavy duty zip lock bags. Store in a cool, dry, dark place.
B/C/D/ Remove and dispose of protective cap B & D and tape C prior to installing
or filter will not function and may implode in filter housing, causing
extensive damage to the compressor and contaminating the air.
E. LifeBandtm changes color from blue to beige along entire length.
Replace ALL cartridges in system at this time. It is advisable to pull out
cartridge every 5 hours to inspect LifeBandtm and for any sign of moisture.
F. Warning label read and understand this and any labels on the filter.
G. Molecular sieve (beige beads) removes humidity
H. Hopcalite catalyst converts trace amounts of carbon monoxide to
carbon dioxide
I. Activated charcoal removes bad odors and taste of lubricant
J. O’ring seal – make sure the O’ring is in place and in good condition.
- Maximum cartridge life, once installed, is six months regardless if it has
not reached the full processing capacity.
- Maximum shelf life in unopened package is two (2) years
Form X302414-IS10.09
2807 Peddler Lane, Kerrville Texas 78028 Ph. 830-257-5006 / Fx.830-257-3720
[email protected] / www.max-air.com
Part Number LF-1002 or X302414 - 10,000 cft @ 72oF @ 5000psi
NOTE: Dimensions exclude threaded plastic nipple w/O’ring
14 1/4” x 1 3/4” dia.
A.
C.
E.
G.
I.
B.
D.
F.
H.
J.
YOU MUST READ AND UNDERSTAND THIS INFORMATION
PRIOR TO FILLING BREATHING AIR CYLINDER!!
DO NOT use where temp. could exceed 120F.

PURIFICATION FILTER CARTRIDGE
REMOVAL & INSTALLATION
For Max-Air Compressor Models 55-70-90-180
1. MAKE SURE that the power is OFF and that all air pressure (high and low) is completely
drained (bled) from the system.
2. In a counter clockwise motion remove the pressure cap assembly “A” from the purification
chamber “B” by inserting a wrench, screw driver or flat bar between the two protruding Allen
screws “C”. DO NOT REMOVE THESE SCREWS OR THE CENTER LARGE ONE as
they are simply for leverage. Remove plastic filter cartridge “D” by unscrewing by hand, counter
clockwise, while holding the double sealed, sealer cap “E” with the other hand, dispose of cartridge
“D” as indicated on cartridge. If you must lay down pressure cap “A” & “E” make sure it is
NOT in contact with sand, dust or dirt. It is recommended to thoroughly clean and re-grease the
threads of cap “A” and O’rings of sealer cap “E” prior to reinstallation. Follow instructions
marked on replacement filter “D”. Remove both orange plastic end plugs or you will not make air.
Tighten cartridge snugly onto sealer cap “E” so that it will not back out with vibration. Tighten the
entire assembly “F” into chamber “B” in a clockwise motion until it stops. Then back out 1/8 of a
turn. DO NOT leave it tight and run compressor, as it can seize inside the chamber.
TOP VIEW OF FILTER
Remove
Replace
Wrench Screwdriver or Flat Bar
Oil level on sight tube should be as
shown Min/Max located behind
purification chamber on the block *
10/07
a
b
c
e
df
*Note: For cabinet models the procedure is the same. The oil level sight glass is
located on the panel and not on block, as shown above. If the filter is
externally mounted, follow above instructions.

1. Intake filter housing 15. Oil and water separator (high pressure)
2. Valve Head 1st Stage 15.A. Oil and water separator (low pressure)
3. Valve Head 2nd Stage 16. Oil and water separator drain tap, high pressure
4. Valve Head 3rd Stage 16.A. Oil and water separator drain tap, low pressure
5. Interstage cooler I –2nd stage 17. Purifier housing
6. Interstage cooler II –3rd stage 17.A. Purifier housing cap
7. After cooler 18. Filter housing drain tap
8. Safety valve 1st stage 19. Pressure maintaining valve (1800 psi)
9. Safety valve 2nd stage 20. Purified air outlets (2)
10. Crankcase casting 21. Final safety relief valve (factory preset to customer requirement)
11. Front bearing cover 22. Check valve—INSIDE upper separator
12. Fan wheel 23. Oil fill vent cap screw
13. Oil filler cap 24. Oil level indicator, behind filter housing (not shown) See figure 1.
14. Oil drain plug 25. Final pressure gauge bar/psi
NOTE: DO NOT RE-ADJUST SAFETY VALVES #8, 9 and 21, unless you are a licensed, qualified high
pressure compressor mechanic (CALL THE FACTORY)! Form MA90Blk-IS004/09
1
16A
2
5
3
8
12
6
23
15
17
11
4
20
16
10
14
19
18
17A
25
2807 Peddler Lane
Kerrville Texas 78028
Ph. 830-257-5006 Fax. [phone]
Email service @max-air.com
www.max-air.com
7
Figure 1. Oil Level Sight Glass
9
13
24
22
Compressor Pumping Group Identification Sheet
Model Max-Air 55, 90 and 180 Twin
21
INSIDE
15A

Construction: Air cooled, three stage,
three cylinder high pressure
compressor, all stainless steel interstage cooling
Max. pressure: 340 bar (5000 psig)
From +10°C to -15°C (50° to 5°F) SAE 10W
Below -15°C (5°F) SAE 5W
Permissible inclination: 5° of compressor at maximum oil level
Warranty: One year from purchase date
Standard equipment: Intake filter, cartridge filter, high pressure hoses, pressure gauge, (2) SCUBA
cylinder filling attachments, pressure relief valves, synthetic compressor oil,
spare parts list and owners manual.
TECHNICAL DESCRIPTION
Model:
Approx. output:
MAX-AIR 90 (265 L/min.) (9.0 cfm)
Interstage pressure: 1 stage 7 bar (100 psig) with interstage safety 2 stage 40-46 bar (570-655 psig)
Safety valves: On all stages. 3 stage 225 - 340 bar (3200/5000 psig)
Bearings: Entire crankshaft assembly on roller bearings
Lubrication: Splash lubrication with oil thrower pin
Oil content: 1.9 Liter/64 Fl. oz. Compact/Cabinet models
Oil type: MAXLUBE #501 synthetic oil
Oil viscosity: Summer: Above +10°C (50°F) SAE20W/40
Winter:
Dimensions: 44"L x 28"W x 35"H
Drive motors: 7.5 HP single/three phase electric motor
SE 5K/6k (9.0cfm)
Weight: 480 lbs (125kg) w/ 7.5 HP motor

2.2 Working System
Ambient air, which must be free from exhaust fumes, is drawn through the intake filter and inlet valve
into the 1st stage cylinder, where it is pre-compressed.
A portion of the compression heat is dissipated through the valve head, piston, cylinder, crankcase and
lubricating oil to the cooling airflow. The larger portion remains in the compressed air and cooled down
in the following intercooler to a few degrees above ambient temperature. The air is then passed on to
the next stages, where it is compressed in the same way. The after cooler cools the air to 10o C above
ambient temperature at the maximum.
Operating temperatures are:
inlet nipples of suction valves approximately 15o- 20oC above ambient temperature (hand warm);
outlet nipples of pressure valves and valve heads approximately 90o- 105oC.
Each stage incorporates an independent preset safety relief valve.
The intake air always contains a certain amount of humidity depending on the weather. During
compression and the consequent cooling down, this humidity largely condensates and forms the
condensate together with small particles of lubricating oil. This condensate is a milky fluid and
precipitates in the separators.
2.3 Technical details of the compressor Block
2.3.1 Crankcase, crankshaft, piston, cylinder
The crankcase is made of light alloy; the bearing cover is sealed by means of an O-ring. The crank-
shaft, connecting rods and piston pins all incorporate roller bearings and grooved ball bearings. The
connecting rods are mounted on the single throw of the crankshaft.
The pistons of the 1st and 2nd stage are made of light alloy and incorporate piston rings.
The 3rd stage piston is a free-floating piston with piston rings. The free-floating piston is driven by a
guide piston, the lateral surface of which is flattened to improve the lubrication of the free piston. The
cylinders are made of cast iron.
2.3.2 Valve heads, valves, intercoolers, separators, filters
The valves are screwed into the well-ribbed valve heads. Valves are arranged side by side and can be
removed by a valve key.
Maintenance of the pressure valves can be carried out from outside, the suction valves can only be
removed after removal of the valve heads. Torque for tightening the valve head screws of the 3rd
stage: start with 1 kpm (7ft.-lb), finish with 2,2 kpm (16 ft.-lb) ensure yourself that piston is down into the
cylinder.

DANGER
2.3.3 Safety valves
The safety valves prevent damage to the compressor by overpressure and are factory set at the
following pressures:
1st stage: 113 psi (8 bar) 2nd stage: 725 psi (50 bar) 3rd stage: 10% above filling pressure
In case a safety valve blows, do not adjust to a higher pressure but check for the cause. Refer to
section 5.
Adjustment of the safety valves, by non-authorized persons, may result in the loss of the
warranty and may result in serious injury or death.
2.3.4 Cooling, lubrication
The 1st and 2nd stage intercoolers and the after cooler consist of steel pipes and are smooth. The
splash lubrication operates with oil thrower pins. The high-pressure stage is lubricated by oil vapors.
2.3.5 Pressure holding valve
This valve is mounted after the purification filter.
Working Procedure
This valve will only open when the internal pressure of the compressor has reached 1800PSI ±
10% PSI (80 ± 10% bar) to permit a constant and optimum separation.
2.4 Base Frame, Protective Frame, Covers
Depending on the specifications of the buyer, the compressor rests on a base frame consisting of
welded section steel with an additional frame bracket for the mounting of electric motors or it is further
equipped with an allover protecting frame. This frame is also made of section steel and its entire
surface is painted to make it weather and corrosion-resistant.
The flywheel of the compressor, in the basic version, is covered by a steel cover or a grid, both being
designed with a view to safety and optimum air guidance.
The front panel incorporates 2 filling valves, final stage pressure gauges and the side panel
incorporates the condensate drain manifold for the manual draining of the filters (special frame version
mod. compact).
WARNING
3. Safety Precautions for The Filling of Cylinders
3.1 General Precautions for the filling of cylinders
Take care that the intake air is pure and free from noxious gases and exhaust fumes.

Make use of the intake hose and secure it in such a way as to ensure that no engine exhaust fumes are
taken in.
Filling hoses must be in perfect condition, connecting threads faultless. Particular attention should be
paid to damage of the connecting fittings. If the rubber is scored, the hose must not be used any longer
because water can enter and attack the wire gauze. In that case it is not guaranteed that the hose is
able to hold the pressure.
Do not open disconnected filling valves when under pressure since the highly compressed air can
cause serious injury or death.
Check air tightness of the complete unit regularly by brushing all fittings and couplings with soap
solution and repair all leaks. (DO NOT USE YOUR HAND/FINGERS TO DETECT LEAKS)
All work on the compressor unit must be carried out with the compressor shut down and depressurized.
On a compressor with an electric motor, disconnect at the power source prior to any work.
Never weld high-pressure tubing.
Never empty air-cylinders completely. The closed cylinder should always contain some residual
pressure in order to avoid the entrance of humid ambient air.
WARNING
4. Installation, Operation, Maintenance, Service
4.1 Installation
Make sure there is good ventilation.
Install the unit on a level ground (maximum permissible sloping 5o), clearance of minimum 2 ft (24”)
completely around the compressor to ensure proper ventilation.
In order to prevent health hazards the intake air must be free from exhaust fumes. This can be effected
by stretching the intake snorkel to its full length, considering the direction of the wind and securing it
approximately 2 m above level ground. Check that the hose is not bent or broken (Table 3).
Do not operate the unit in closed or partly closed rooms, whatever size. This applies to all units
with gas or diesel engines.
Table 3: Location of the intake hose

4.2 Starting-up
Before starting engine check oil level in the crankcase of the horizontally placed compressor ( § 4.8.1)
Use MAXLUBE #501 synthetic oil.
Starting of the engine:
Before starting electric motors, check voltage. Electric connections must comply with the respective
regulations. Verify fan direction. Compare motor with mains and frequency. Fuse motor correctly.
Check direction of rotation. The use of a motor starting contactor is recommended. If using a gasoline
engine driven compressor, check oil level in motor and compressor (§ 4.8.1)
Before starting the engine, open condensate drain valve so that engine starts without load. Pull the
choke (half open). As soon as the motor has been started, switch to full power, then close condensate
drain so that pressure is built up in the individual stages.
WARNING
4.3 Filling procedure
Use only cylinders that are within hydro test date and pressure rated to the fill pressure preset on your
compressor. The preset pressure relief (blow-off) on the final stage is usually 10% above the cylinder
rated pressure.
Example: if you are filling a 3000 psi rated cylinder you should close the fill valve or shut off the
compressor at 3000 psi (NOT ABOVE IT). The 10% additional pressure, preset on
the relief valve, is just an added safety in case you can not shut off in time. Letting
the relief valve blow-off often will damage it, as it is designed to blow-off for emergency
only.
To check the pressure blow-off of your final relief valve, close the fill valve and bleed, let the
compressor build up pressure. When safety valve blows-off read the pressure at the final pressure
gauge and make a note of it for the future. After you are satisfied that the setting is correct for your fill
pressure fully open filling valve first, then open cylinders valve –monitor fill pressure during filling
operation. After reaching the desired pressure, always close cylinder valve first, then close the fill
valve. To remove fill valve from cylinder you must bleed the residual pressure by opening the bleed
cock on the fill valve.
Operation of filling valve
Bleed Cock
On/Off Knob