Ariel JGJ Series, Technical Manual

Page: 48 / 141

F
OR
M
ODELS
: JGW, JGR
AND
JGJ S
ECTION
4 - L
UBRICATION AND
V
ENTING
PAGE 4 - 4 1/01
4. Resistant to hydrocarbon gas dilution. Excellent wetability.
5. Can be water soluble - must verify application with lubricant supplier.
6. Poor inherent oxidation stability and corrosion protection - requires additives.
7. Not recommended for air compressors.
Compressor Frame Lubricants
Ariel recommends, for use in the compressor frame, a good quality mineral oil which pro-
vides proper lubrication and heat removal, as well as oxidation inhibition, rust and corrosion
inhibition, and anti-wear properties.
The minimum viscosity at operating temperature is 60 SUS (10 cSt).
For clean, dry, pipeline quality gas, the oil used in the natural gas fueled engine should be
satisfactory. SAE 40 weight (ISO 150 grade) oil is recommended for normal operation.
Low ash or no ash oils are recommended as high ash oils can increase maintenance
requirements.
Additives must not be corrosive to lead or copper based bearing materials.
The compressor frame driven lube oil pumps maintain oil pressure with a spring loaded reg-
ulating valve within the pump head. Lube system pressure can be raised or lowered by
adjusting this valve. Normal pressure on the discharge side of the lube oil filter is factory set
for 60 psig (4.1 bar
g
). If the lube oil pressure drops below 50 psig (3.4 bar
g
), the cause
should be found. A low lube oil pressure shutdown, set at 35 psig (2.4 bar
g
), is required for
protection of the compressor.
The maximum viscosity of the lube oil for cold ambient temperature starting is 15,000 SUS
(3300 cSt), typically 40°F (4°C) for SAE 30 weight (ISO 100 grade) oil, or 55°F (13°C) for
SAE 40 weight (ISO 150 grade) oil.
The minimum lube oil operating temperature is 150°F (66°C). This is the minimum tempera-
ture required to drive off water vapor.
When frame lube oil immersion heaters are used, the watt density of the heater element
should not exceed 8 watts per square inch (1.2 W/cm
2
) for systems without circulating
pumps. Oil coking will occur at the element with higher wattage heaters if a circulating pump
is not used. When high wattage heaters are required, the heaters must be interlocked with
an oil circulation pump to ensure that coking of the oil will not occur. Coked oil will form
deposits which can “insulate” the system and decrease heat removal. The deposits can also
break loose and act as abrasives in the lubricating system.
JGW, JGR and JGJ compressors are equipped with simplex, spin-on, resin-impregnated
type filters as standard. Pressure gauges are provided for monitoring pressure drop across
the filter.
Compressor frame lubricating oil should be changed at regular maintenance intervals (6
months or 4,000 hours), when oil filter differential pressure exceeds 10 psi (0.7 bar) or when
oil sample results indicate the need. A more frequent oil change interval may be required if
operating in an extremely dirty environment or if the oil supplier recommends it.