Figure 5-20. - Operating controls and component indentification of Clayton steam generator, Model RO-33-PL, rear view.

burner causes reduced burner efficiency. The frequency of cleaning depends on the amount of dirt or lint in the air at the installation.

Check the operation of the thermostat control every 100 operating hours. Consult the manufacturer's instructions for test procedures.

When a water pump is noisy, the trouble is sometimes due to a restricted heating coil that causes excessive feed pressure. The feed pressure should be checked for coil restriction. When checking for coil restriction, compare the reading on the feed pressure gauge with that on the steam pressure gauge. Normal feed pressure may vary slightly with each installation. Carefully note the pressure right after the steam generator is installed, so an accurate check of coil restriction can be made for the unit. The coil is restricted if feed pressure is 30 pounds or more above the normal feed pressure noted immediately after installation or when the coil was completely clean.

The steps of the procedure used to blowdown the system are as follows:

1. With the plant operating at normal steam pressure, close the circulating feed valve (E) and open the coil drain valve (J). Start a time check. After 30 seconds, shut off the burner and close the steam discharge valve (B).

NOTE

If the burner is shut down by the thermostat control during the time check, immediately open the burner control valve (K); then close the steam discharge valve.