8
Sentry Equipment Corp
Operation
Models X43-C to X89-CK for Single Boilers
The level of dissolved solids or specific conductance should be adjusted to prevent
foaming, priming, scaling, etc. Information can be obtained from your water treatment
firm(s) on the required level to maintain and the preferred testing method. If you do not
have the proper equipment to make these tests to determine the condition of your boiler
water, we suggest that you purchase a portable conductivity meter to determine how
much you should blow down. If your boiler tests too high, blowdown more. If it tests too
low, reduce the amount of blowdown.
To adjust the amount of blowdown, open or close the handwheel on the thermometer
end of the blowdown unit. Turning the handle slightly counter clockwise will increase
blowdown as the valve opens; turning the handwheel clockwise will reduce the amount of
blowdown. The thermometer in the control unit gives an indication as to the relative flows
of the make-up and blowdown. It will aid you in adjusting the handwheel. If you need
more blowdown, open the valve enough so the thermometer reads, say 5°F (3°C) higher in
steady operation and vice-versa.
The step-by-step instructions for starting the blowdown unit are:
1.
Open the two (2) customer supplied make-up water isolation valves to allow the
make-up water to flow through the heat exchanger shell.
2.
Close the customer supplied by-pass valve in the make-up water line to force all of the
make-up water through the shell.
3.
Open or close the handwheel on the control valve to adjust the temperature of the
blowdown to approximately 27°F (15°C) above the make-up water for X4C units,
21°F (12°C) for X6C units, or 18°F (9°C) for X8C units. This temperature reading must
be made when the unit has reached steady state. Check the concentration of the
boiler water every few hours until a trend is noted upward or downward. If the trend
is towards too high a concentration, open the handwheel slightly,
⅛
to ¼ of a turn.
You will note that the blowdown from the unit may flow heavily at times or not at
all at other times. This is normal as this is the way the make-up flow is occurring.
After several weeks of operation you will find a control point to maintain your boiler
concentration and a simple daily check from then on should assure you of a properly
blown down boiler.
Models X43-CM to X89-CKM for Multiple Boilers
The XCM’s will be operated exactly as the XC’s above, but in addition require the balancing
of the flow control valves for the load being carried by each of the boilers.
Proceed with the start up of this unit exactly in the same manner as the single boiler units
above with the Tasco Flocontrol Valves set in the half open position. The Tasco Flocontrol
Valve openings must be set in accordance with the approximate load that each boiler is
taking. This balancing should be done, however, so that the average valve openings are
always one-half. If there are two valves and one is set at a ¼ opening, the other should