A Division of Sussman-Automatic Corporation
PN 101167 5/12
43-20 34th Street, Long Island City, NY 11101
•
718-937-4500
•
1-800 238- 3535
Fax: 718-937-4676
•
www.sussmanboilers.com
•
Email: [email protected]
ES 24A Electric Steam Generator
Installation, Operation and Maintenance Manual
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8
For optimum results, the feedwater supply should be tested prior to initial start-up. If the
mineral content exceeds the following recommended limits, various external treatment processes (water sof-
tener, reverse osmosis, etc.) may be used to correct the problem.
NOTE:
An analysis of the on-site boiler feedwater must be made by a
recognized and reliable water treatment company to ascertain the existing
condition and treatment required.
RECOMMENDED FEEDWATER QUALITY
HARDNESS, ppm
8 – 85 (~0.5 – 5 gpg)
P-ALKALINITY, ppm
85 – 410 (~5 – 24 gpg)
T-ALKALINITY, ppm
200 – 500 (~7 – 0 gpg)
pH (strength of alkalinity)
8.0 – 11.4
SPECIFIC RESISTIVITY
~50k
Ω
cm (50,000 ohm-centimeter)
Blow down the boiler on at least a once-a-day basis. If boiler water or feed-water are
outside the above limits, a more frequent blowdown is required.
RECOMMENDED LIMITS WITHIN A BOILER
TOTAL DISSOLVED SOLIDS, ppm
3500
TOTAL ALKALINITY, ppm
850
SUSPENDED SOLIDS, ppm
300
SILICA (Si02), ppm
125
SULFITE (SO3), ppm
25–50
PHOSPHATE, ppm
30–60
P-ALKALINITY AS CaCO3, ppm
900
IRON, ppm
2
Water quality can affect efficiency or result in boiler damage if neglected. Boiler feedwater contains impuri-
ties in solution and suspension. These impurities concentrate in the boiler since the steam generated is
essentially pure. The concentration of these impurities increases as more feedwater is introduced into the
boiler and steam is produced. If the suspended solids are allowed to concentrate beyond certain limits, a
deposit or “scale” will form on the boiler’s internal surfaces. This deposit can interfere with proper boiler
operation and cause boiler failure.
The concentration of these impurities is generally controlled by the feedwater quality and by blowdown.
Blowdown refers to removing a portion of the boiler water with high solids concentration and replacing it
with make-up water of a lower concentration.
Water Quality Information for Carbon Steel Boilers