Columbia CT-10, Installation, Operation And Maintenance Manual, Page: 28 / 56

COLUMBIA BOILER COMPANY, REV 2-17
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Gauge Glass
The water gauge glass must be kept clean. Dirt on or in the glass may be mistaken for the
water level. Do not allow steam or water to leak from the water glass, as this may effect
the accuracy of the level indication. Leaking of the gauge glass will also reduce the wall
thickness of the glass to the point where it may explode.
DO NOT OPERATE THE BOILER WITHOUT THE GAUGE GLASS PROTECTOR
INSTALLED. NEVER ATTEMPT TO WORK ON THE GAUGE GLASS WHILE THE
BOILER IS UNDER PRESSURE. ALWAYS CLOSE GAUGE VALVES PRIOR TO
TIGHTENING GASKETS ON WATER LEVEL GAUGE GLASS. SERIOUS
INJURY COULD RESULT.
Gauge Glass Replacement Instructions:
1. Make absolutely certain that the new water level gauge glass is 5/8" o.d. x 10-
1/4" long Pyrex red line, high pressure, high temperature glass tubing with fire
polished ends.
2. Close gauge glass valves.
3. Remove gauge glass protector.
4. Remove the old glass, gaskets, brass washers, and brass nuts. Be sure threads on
the gauge valves are clean.
5. Install brass nuts, brass washers, and gaskets on each end of the gauge glass.
6. Insert glass tube into top gauge valve and lower the glass tube into the bottom
gauge valve which contains a seat. Then raise glass 1/16". Do not allow glass
to rest directly on the valve.
7. Hand tighten the lower glass nut and then the upper nut. While tightening these
nuts, be sure to keep the red line opposite the viewing side.
8. With a wrench, snug up the bottom nut and then the top nut.
9.
Replace gauge glass protector.
Open gauge glass valves fully. Failure to
completely open the gauge glass valves renders the ball check safety feature
inoperative.
10. Without pressure on boiler and with gauge valves closed, tighten gaskets again
after 1 day of operation.
Blowdown
Blowing down the boiler is done to remove excess total dissolved solids. The actual amount
of blowdown should be determined through boiler water analysis, done by a water treat-
ment specialist. Until an analysis of your boiler water is made, the following guidelines
should be used.
Blow down should be done in the evening after firing equipment has been shut down for
approximately 20 minutes and at a pressure between 20 and 40 psi. Some pressure must
be left on the boiler for proper blow down.
Important: Boiler water must be settled for
proper blowdown.
WARNING