Figure 5-16. - Flow diagram of the water and steam circuit in a generator.

line to the return connection below the fuel pump. The return line must be a separate line back to the fuel tank and NOT connected to the fuel suction line to prevent locking of air in the fuel system that will cause erratic burner operation. Do NOT install a shutoff valve in the return line; however, a swing check valve may be installed if the fuel pump is below the fuel tank.

Install a stack adapter (supplied with the steam generator) directly on the heater cover stack outlet. Install a stack extension if desired, using 12-inch-diameter flue pipe (minimum), and install a weather cap (supplied with the unit) at the top of the flue pipe. If the unit is operated in an enclosed building, extend the flue pipe through the roof and install a weather cap.

Typical hot-well installation and connection data are shown in figure 5-17. The hot well must be elevated on a suitable stand or bracket to allow a 60-inch gravity feed to the inlet of the feedwater pump check valve housing for hot-well temperatures up to 180F. If higher hot-well temperatures are anticipated, a higher gravity feed is required to prevent vapor locking of the feedwater pump. For hot-well temperatures of 180F to 200F, a 72-inch gravity feed is necessary. Temperatures above 200F require a gravity feed of 84 inches.

The feedwater connection is made by connecting a line between the feed pump connection on the hot well and the feedwater intake valve. The connection is made by using a minimum of 1-inch-diameter pipe.

The steam header should be connected to the steam discharge valve. Ensure that the header pipe size is not smaller than the steam discharge valve.

A valve bleed line to the atmosphere should be installed at the steam discharge. This design 5-18