Use
35
The pressurisation must fall within the values indicated in the table of the technical data.
m
IMPORTANT
The temperature difference between flow and return must not exceed 30°C in order to avoid thermal shocks to the
boiler.
The return temperature from the system must be higher than 50°C with operation with methane gas or LPG and
40°C with operation with fuel oil or naphtha to protect the boiler against corrosion due to the acid condensate of
flue gases.
Therefore, the warranty does not cover damage caused by the condensate.
It is useful to mitigate the return temperature by installing a mixing valve and/or a recirculation pump.
The burner switch must always be kept on.
In this way the temperature of the water in the boiler will be kept approximately at the value set with the thermostat.
In case of poor smoke sealing in the front part (door and burner plate) or rear part (smokebox) of the boiler, it is necessary to adjust
the closing tie-rods of the single parts.
If this is not enough, replace the relevant gaskets.
m
ATTENTION
Do not open the door and do not remove the smokebox while the burner is in operation and, in any case, wait for a
few minutes after it is turned off to allow the cooling down of the insulating parts.
STOP PERIODS
The most serious corrosions for the generator often occur during the stop periods.
The operations to be carried out to store the generator correctly essentially depend on the duration of the downtime. When the
generator needs to be stopped
for long periods
,
dry storage
can be done. When the stops are
for short periods
or when the
generator is used as a spare and must start running in a short amount of time, a
wet storage
can be made.
In both cases, the operations described below tend to eliminate any possible cause of corrosion.
When possible, wet storage reduces the time required to reach the operating conditions.
Dry storage
It is necessary to empty and dry the generator carefully, subsequently pouring a hygroscopic substance inside the cylindrical body
(e.g. quick lime, silica gel, etc.).
Also drain the condensate collection tank and all pipes.
Wet storage
Drain the water out and clean the entire generator. Fill the unit up to the normal operating level, and after a brief period of
evaporation it is essential to vent all the dissolved gases into the atmosphere. Then, completely fill the generator, using enough
DEHA (diethyl hydroxyl amine) to develop a residual concentration of more than 100 ppm, to prevent the attacks of oxygen
dissolved in the water. Also add trisodium phosphate, so that the overall alkalinity is greater than 400 ppm.
Then, close all the connections.
Make sure there are no leaks from the connections or joints and draw samples of water at regular intervals, to check that the
alkalinity value has not been altered.
Cooke Industries - Phone: +64 9 579 2185 Email: [email protected] Web: www.cookeindustries.co.nz
