Blodgett KLT-G Series - Manual (Page 17)

OM-KLT-G 15
Maintenance
B. Jacket Vacuum/Removing Air from Jacket
When the kettle is cold, a positive pressure reading on the pressure/vacuum
gauge or a reading near zero indicates that there is air in the jacket. Air in the
jacket acts as an insulator, and slows kettle heating.
To remove air:
1. Start the unit. (Be sure there is water or product in the kettle when heating).
2. When the pressure/vacuum gauge reaches a positive pressure reading of
five PSI, release the trapped air and steam by pulling up the safety valve
ring for about five seconds. Repeat this step three or four times. Then let
the pull ring snap back into the closed position.
3. If there is little discharge (mostly air), and the pressure gauge drops back
to zero PSI, allow the pressure to build back to five PSI and repeat the
procedure.
4. Once steam has been vented from the jacket as described in 2, above,
remove the hot water from the kettle and replace it with cold. This will
condense steam in the kettle jacket, and the pressure gauge should
show a reading of 20 to 30 inches mercury (Hg) below zero. If it does
not, or if the vacuum is leaking down, contact an authorized service
agency to correct the problem.
C. Jacket Filling and Water Treatment
The jacket was charged at the factory with the proper amount of treated water.
You may need to restore this water, either because it was lost as venting steam
or by draining. If you are replacing water lost as steam, use distilled water. If
you are replacing treated water that ran out of the jacket, prepare more treated
water as directed in “Water Treatment Procedure,” below.
Allow the kettle to cool completely. The procedure will be easier with the
kettle under vacuum (pressure gauge reading below zero).
1. Make sure the fill valve is closed, and remove the square head pipe plug
with open-ended wrench.
2. Position a funnel in the opening and fill it with properly treated water.
3. Slowly open the fill valve to allow water to be sucked into the jacket.
Quickly close the valve to prevent air from entering.
4. Check water level in the jacket to ensure that it is between minimum and
maximum marks on glass or at the top of the sight glass port (see photo
on page 15).
5. Close the valve and reinstall the square-head pipe plug.
6. Reestablish the jacket vacuum as described in Paragraph 2, above, if
the pressure gauge does not show a negative reading of 20 to 30 inches
mercury (Hg).
Liberally grease the wheel
where it contacts the worm gear.
Test the safety valve at least twice monthly.