3.1.3DRAINING THE SYSTEM
A clean neutral hot water system should not be drained, except for an emergency or when unavoidable for servicing of equipment. See Section 3.3 for water treatment required when refilling.
3.2REPLACEMENT BOILER
INSTALLATIONS: PROTECTION
AGAINST CORROSION AND SEDIMENT
Clean or replace all system piping and heating units
Arrange for chemical or mechanical cleaning of the entire system. A chemical treatment company should be consulted for the proper means of any chemical cleaning.
Replace any piping that is deteriorated beyond safe or cleanable condition.
Flush the system clean, being certain to isolate the boiler.
WARNING:
DO NOT FLUSH THE SYSTEM
THROUGH THE BOILER.
For some old systems, there is a reluctance to clean the piping because of possible leaks occurring in badly corroded lines. Should the customer refuse cleaning, it is necessary to install filtration equipment. Install either a fibrous filter or a centrifugal filter in the boiler return piping. This will collect and remove sediment from the system. A booster pump may be required to overcome the additional pressure drop introduced in the line by the filter. When filling the system, provide chemical treatment as outlined in Section 3.3.
Failure to properly clean the system or to install mechanical sediment removal equipment can result in tube blockage and severe corrosion plus damage to pumps, controls, and air removal devices.
Inspect, repair as necessary, or replace system air control devices.
Install gauge glasses on air expansion tanks and install a tank fitting in the system connection to
52
Date: 8-4-2010
Revision: 0
Form: 2396
the tank.
Install a strainer in the boiler return piping.
3.3BOILER WATER TREATMENT
Purpose of water treatment
Water treatment is required for satisfactory operation of the boiler. It must be devised to prevent depositing of scale and corrosion from acids, oxygen and other such harmful elements that may be in the water supply. A qualified water treatment chemist should be consulted and the water systematically treated.
Objectives
The basic objectives of water treatment are: Prevent the accumulation of scale and deposits in the boiler.
Remove dissolved gases from the water. Protect the boiler against corrosion.
Maintain the highest possible boiler fuel efficiency.
Decrease the amount of boiler down time from cleaning.
Water softener
It is highly recommended that a zeolite water softener be used for all
Continuous monitoring required
Water treatment should be checked and maintained whenever the boiler is operating. The boiler operator should be sure that the boiler is not operating for long periods without proper water treatment.
Water treatment may vary from season to season or over a period of time. Therefore, the water treatment procedure should be checked not less than four times a year, and possibly more frequently as the local water conditions may indicate.
It should be noted that water boilers may well need chemical treatment for the first filling plus additional periodic chemical treatment, depending on system water losses and the makeup requirements.
Water treatment may vary from season to season or over a period of time. Therefore, the water treatment procedure should be checked
