Schwing SP 500 - Hydraulic Oil Viscosity Chart

119
Appendix
SP 500 / 750-15 / 750-18 / 1000 / 1250 Operation Manual
Hydraulic Oil Viscosity Chart
The illustration below shows the relationship between
the oil temperature and its viscosity. As you can see, the
oil gets thicker when the temperature is low and thinner
as the temperature rises.
Your Schwing concrete pump was delivered with Mobil
Univis N46 hydraulic oil. This multi viscosity works for
any temperature between -20˚ F and 100˚ F. If you have
chosen to change to a regular viscosity oil, pay close
attention to the following.
• The cold start limit represents the coldest tem-
perature at which the oil is thin enough to ow into
the hydraulic pumps. If it were any colder, the
pumps would not be able to suck in the oil (cavita-
tion).
• The minimum permissible viscosity represents the
warmest temperasture at which the oil will still be
thick enough to provide lubrication and sealing. If
it were warmer, the components would have met-
al-to-metal contact (thermal breakdown).
• The optimum operating viscosity is the range of oil
thickness at which the oil works best (thin enough
to ow easily, yet thick enough to protect the sys-
tem components).
• An example of how to read a chart for VG-46 oil is
given in the chart below. The chart shows the cold
start limit as –8°C (18°F) and the minimum per-
missible viscosity as 90°C (194°F). The optimum
range is 50°– 76°C.
-40 -30 -20 -10 0102030405060708090 100 110 120
-40 -30 -20 -10 0102030405060708090 100 110 120
Temperature of Hydraulic Oil
-40 -22 -4 14 32 50 68 86 104 122 140 158 176 194 212 230 248
(C)
(C)
(F)
C = degrees Celsius
F = degrees Fahrenheit
Water freezes
Water boils
Cold Start Limit
(very thick oil)
Minimum permissible
viscosity
Optimum
Operating
Viscosity
VG 22
VG 32
VG 46
VG 68
VG 100
temp chart.eps