EMX, EMXO and EMXGO SERIES WATER BOILERS
34-503 07/13
16
17 MAINTENANCE (con't)
5. The pressure safety valve should be checked at regular intervals by manually opening the valve. The
openings inside the valve may become restricted by a buildup of scale and become inoperative. If the
valve does not open and close properly, it must be replaced. Shut down boiler, relieve internal pressure,
and replace safety valve with a like kind or one meeting the requirements stated on the rating decal
located adjacent to the safety valve mounting location.
CAUTION: The safety valve is a
primary
safety device.
6. The need to periodically check water level controls and waterside of the pressure vessel cannot be over
emphasized. Most instances of major boiler damage are the result of operating with low water or the use
of untreated (or incorrectly treated) water.
7. Every boiler is equipped with an electronic low water cutoff. This device senses continuity between a
probe located in the top of the tank and the water to verify the presence of water. It is important to check
the operation of this device periodically.
8. This boiler may be equipped with a float-type low water cutoff. Since low water cutoff devices are
generally set by the original manufacturer, no attempt should be made to adjust these controls to alter the
point of low water cutoff. If a low water device should become erratic in operation or if its setting changes
from previous established levels, check for reasons and correct; repair or replace as required.
The controls' operation may be checked by stopping the water supply to the boiler while the burner is
operating at low fire. While under constant attendance allow the water to lower at a normal rate. If a
control does not break the circuit to stop the burner at the proper point, then
SHUT DOWN THE BURNER
IMMEDIATELY
.
Do not restart until all cross connecting piping is checked for obstructions. Also check the float bowl. If
these are clean, repair or replace the control. Repeat the above test to insure proper operation prior to
returning the boiler to service.
Remove the pipe plugs from the tees and crosses and make certain the cross connecting piping is clean
and free of obstructions. Controls must be mounted in a plumb position for proper performance.
Determine piping is vertically aligned after shipment and installation and throughout the life of the
equipment. The operation of the electronic low water cutoff may be checked in the same manner, by
bypassing the function of the float low water cutoff.
9. It is important to blowdown the float low water cutoff devices when supplied. It is recommended that a
short blowdown be conducted daily. Float low water cutoffs should be equipped with test-n-check valves
to allow blowdown of low water cutoff without requiring complete drainage of the boiler.
10. A boiler used for heating or seasonal loads or for standby service may have an extended period of non-
use. Special attention must be given so that neither waterside nor fireside surfaces are allowed to
deteriorate from corrosion.
11. There are two methods of storage – wet or dry. Your water consultant or feedwater treating company can
recommend the better method, depending upon circumstances in a particular installation. Section VII of
the ASME Code also contains information relating to laying up a boiler.
12. Extended shutdown of the boiler and restarting are as follows:
a. Turn off all power and fuel supplies.
b. Enter boiler into dry storage.
c. Tag power switch(s) that fuel is off and tank is in storage condition.
d. Remove tank from storage and turn fuel and power switch(s) on to start. Reset all controls and
conduct startup of the boiler as discusses previously.