CleaverBrooks 4WI, Operation, Service And Parts Manual

Page: 140 / 216

Inspection and Maintenance
8-22 750-211 (revised 2009)
Promethean Boilers, Model 4WI Manual
14.
Replace the metering stem and spring. Lightly lubricate the stem to facilitate insertion and easy movement. Use
care when inserting so that the orifice and the stem are not damaged.
FIGURE 8-27.
Fuel Stem Packing, Cross-Section
15.
Snug the packing gland, but only sufficiently to place slight tension on the packing. The stem must move freely
from the force of the spring.
16.
Work the stem up and down several times to ensure that it moves freely.
17.
Depress the valve stem and replace the cam. Mate the match-marks and secure the setscrews. Be sure the cam
spring is centered in the roller.
18.
Restor oil flow. Test fire the burner at various firing rates being certain that the metering stem freely follows the
cam.
19.
Tighten the packing gland after a period of operation, if necessary, to maintain proper pressure on the packing.
Do not over-tighten.
If there are indications that the oil metering valve has become clogged at its orifice, it will be necessary to disassem-
ble the control to remove the obstruction. Clean the slotted stem of the oil metering valve with suitable solvent and
blow-dry with dry shop air. Follow the procedure outlined above when removing or re-installing the metering valve
stem. Also check all fuel line strainers.