16
C.
PIPING
The following pages show piping schematics for various applications, one of which
should suit your needs.
All piping connections to the radiator should be externally supported; not hung on the
radiator. Flexible connections are required when connecting piping to a radiator. Piping
and connections should be designed to isolate the radiator from vibration and thermal
expansion loading. Piping should be of ample size and with as few bends or elbows as
possible. Use long sweep elbows or long bends.
CAUTION! When piping is higher than the radiator, the piping high points (both
supply and return) must also be vented to the surge tank!
WARNING! Improper connection of piping or improper filling may cause engine
damage.
1. ENGINE-MOUNTED RADIATORS
All engine-mounted radiators should be piped as shown in Figure 4. The radiator top
tank must be the highest point in the system and a 1/4 inch to 1/2 inch (*) vent line
from the engine thermostat housing to the radiator top tank may be required.
When the radiator has a deaeration baffle in the top tank, the plumbing is as illustrated
in Figure 5. A 3/4 inch to 1 inch (*) line from the engine water pump to the radiator
top tank pump suction port is required, and a 1/4 inch to 1/2 inch (*) vent line from the
engine thermostat housing to the radiator top tank is recommended. A fast fill port may
be provided on radiators with a deaeration baffle. This port is used to initially fill the
radiator. If a fast fill port is not available, fill through the radiator inlet(s). After initial run
up, recheck the system to be sure it is filled. Connection of the deaeration system
should be in accordance with the engine manufacturer’s recommendations.
2. VERTICAL REMOTE MOUNTED RADIATORS
Vertical type remote mounted radiators should be piped as shown in Figure 6. The
radiator top tank should be the highest point in the system. The customer should also
install a drain valve at the lowest point in the system.
When a separate surge tank is required with a vertical remote radiator, the system is
piped as in Figure 7. The surge tank should be the highest point in the system and a
3/4 inch to 1 inch (*) fill line is required from the bottom of the surge tank to the
radiator outlet pipe or pump suction line. Connecting the surge tank fill line to the
radiator top tank may cause pump cavitation, depending on the elevation of the radiator
with respect to the engine. If the engine is higher than the radiator or the engine
requires it, a 1/4 inch to 1/2 inch (*) vent line is required to the surge tank from the
thermostat housing or the highest point in the system. The customer should install a
drain valve at the lowest point in the system.
(*) Size of vent lines or filling lines is dependent on engine size and the
engine manufacturer’s recommendations.