CleaverBrooks CBEX Elite, Operation And Maintenance

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750-368
CBEX Elite 100-1200 HP 5-5
5.5 — Firing Preparations for No. 2 Oil (Series 100-200)
where it becomes inoperative (or removed and openings plugged). To render inoperative, turn the adjusting screw
in as far as possible.
A standardly equipped boiler has a selector switch incorporated in the oil pump motor starter. Momentarily ener-
gize the starter to check for proper pump rotation. With the rotation verified, operate the pump to determine that
oil circulation exists. Observe the oil burner pressure gauge for indication that flow is established. If no pressure
shows on the gauge after a few moments, stop the oil pump and re-prime. If the supply tank is lower than the
pump, it is possible that the initial priming of the suction line, followed by operation of the pump, will not estab-
lish oil flow. This might be caused by obstruction in the suction line, excessive lift, inadequate priming, suction
line leaks, etc. If oil flow is not readily established, avoid prolonged operation of the pump to minimize risk of
damage to internal parts of the pump. If oil flow is not established after a second or third priming attempt, a full
investigation is required to determine the cause.
A vacuum (or a compound pressure-vacuum) gauge should be installed at the suction port of the pump and its
reading observed and recorded for future guidance. If a vacuum condition exists, the reading will reveal the tight-
ness of the system. It is advisable to maintain the vacuum reading at less than 10” Hg. A vacuum in excess off
10” Hg may allow oil to vaporize, causing cavitation, loss of prime, and an unstable firing condition.
Oil supply pressure is regulated by adjusting the pressure relief
valve at the oil terminal block. A pressure gauge should be
installed in the terminal block and the relief valve adjusted to
obtain a minimum reading of 75 psi when the burner is firing at
maximum rate.
FIGURE 5-3.
Oil Terminal Block
Adjustment may also be required to the regulator on the fuel oil controller. The pressure regulating valve is
equipped with tubing that directs and adds atomizing air pressure to the adjustable spring pressure. Since the air
pump is not running at this time, only tentative adjustment can be made. Without the air supply, adjust the fuel
oil pressure regulator so that the oil burner gauge registers approximately 35 psi.
The pressure gauge will indicate a higher reading when air is present and the flame exists and will increase as
the firing rate increases. After the burner is firing and when the air pump is running, final adjustment can be
made at the fuel oil controller.
Relief Valve
Pressure Gauge