Install drain plugs as you repair the piping. Use an appropriate thread sealant for
the fluid being used (see Appendix E).
Dispose of the used oil properly, according to local requirements.
If a fill/drain assembly similar to the one in Figure 5-26 is not part of the system,
install one. It can be placed in any part of the loop which contains the flow of all the
fluid, but an ideal spot is between the system low point and the return line coming
from the collectors.
with Charging Pump
Normally a check valve is used, as shown. A gate or ball valve can be used
instead, but only if a working check valve is somewhere else in the loop. Having
two check valves in the loop is acceptable, since one can back up the other.
Make sure the seals and seat of the valves used are compatible with the solar fluid.
Use an appropriate thread sealant.
Flush the system with a cleaning solution recommended by the oil manufacturer, or
with new oil. This process is identical to charging a system, described below,
except that the cleaning solution is drained afterward. Always handle and dispose of
the cleaning solution property, in accordance with local regulation.
5.2 REPAIR PROCEDURES