Max-Air Systems 90 PBAC Operation manual

Model # Max-Air 90 PBAC 9.0 cfm
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 2006.
This manual cannot be reproduced without the express written permission of Max-Air.
WARNING!
DO NOT USE WITH ENRICHED AIR SYSTEMS, ABOVE 21% OXYGEN
(the use of enriched air, above 21% oxygen, will void manufacturer’s warranty)
High Pressure Breathing Air Compressors
Revised 6-30-21

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 Do not fill out-of-date, (hydro-date) cylinders for anyone.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.
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Construction: Air cooled, three stage,
three cylinder high pressure
compressor, all stainless steel interstage cooling
Max. pressure: 340 bar (5000 psig)
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
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
Weight: 276 lbs (125kg) w/9 HP Honda engine
Dimensions: 42"L x 20"W x 28.5"H
MAX-AIR 90(9.0cfm)
TECHNICAL DESCRIPTION
Model:
Approx. output: MAX-AIR 90 (260 L/min.) (9.0cfm)
Drive motors: 7.5 HP single/three phase electric motor (MAX-AIR 90)
9 & 6.5 HP gasoline engine
9 HP diesel engine
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Oil viscosity: Summer: Above +10°C (50°F) SAE20W/40
Winter:
Standard equipment: Intake filter, cartridge filter, high pressure hoses, pressure gauge, (2) SCUBA
cylinder filling attachments, pressure relief valves, 60 oz. synthetic compressor
oil, spare parts list and owners manual.
Lubrication: Splash lubrication with oil thrower pin
Oil content: 1.7Liter/58 Fl. oz.
Oil type: MaxLube 501 synthetic oil

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.
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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: 5000 psi (340 bar).
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 carbon filter.
Working Procedure
This valve will only open when the internal pressure of the compressor has reached 1800PSI ±300 PSI
(80 ±20 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.
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