Burnham Series 4N Boiler Instruccion De Instalación

8. BOILER WATER TREATMENT

Boiler water treatment will help maximize the

effectiveness and prolong the life of pressure

vessels.

The general objectives of boiler water

treatment are:
A. Remove corrosive gases from feedwater and

boiler water.

B. Prevent sludge and scale deposits on the water

side heating surfaces.

C. Prevent foaming and carryover.

Consult with a local water treatment company

regularly engaged in the treatment of boiler water

for advice in maintaining the proper feedwater, boiler

water, and condensate chemistry.

Certain state and local codes may restrict the use of

some chemicals listed for cleaning and maintaining the

boiler. Check with local authorities before proceeding

with the use of any chemicals.

9. MAKE PH OR ALKALINITY TEST

After boiler and system have been cleaned and

refilled as previously described, test the pH of the water

in the system. This can easily be done by drawing a

small sample of boiler water and testing with hydrion

paper which is used in the same manner as litmus

paper, except it gives exact readings. A small color chart

on the side of the hydrion dispenser gives the reading

in pH. Hydrion paper is inexpensive and obtainable

from any chemical supply house or through your local

druggist. The pH should be higher than 8.3 but lower

than 10.5. Add some washout chemical (caustic soda), if

necessary, to bring the pH within the specified range.
10. FREQUENT WATER ADDITION

If, during normal operation, it is necessary to add

water more frequently than once a month, consult

a qualified service technician to check your system

for leaks.

A leaky system will increase the volume of make-up

water supplied to the boiler which can significantly

shorten the life of the boiler. Entrained in make-up

water are dissolved minerals and oxygen. When the

fresh, cool make-up water is heated in the boiler the

minerals fall out as sediment and the oxygen escapes

as a gas. Both can result in reduced boiler life. The

accumulation of sediment can eventually isolate

the water from contacting the cast iron. When this

happens the cast iron in that area gets extremely hot

Oxygen contamination of the boiler water will cause

corrosion of iron and steel boiler components, and

can lead to boiler failure. Burnham’s standard

warranty does not cover problems caused by

oxygen contamination of boiler water or scale

(lime) build-up caused by frequent water addition

or by improper water chemistry as shown below.

Minimum Water Quality Requirements

pH - 8.3 - 10.5
TDS - 3500 ppm
Total alkalinity ppm as CaCO

- 1200

Total copper ppm - .05
Oily matter ppm -1
total harness ppm -3

Chlorides - < 50 ppm

There are many possible causes of oxygen

contamination such as:
a. Addition of excessive make-up water as a result

of system leaks.

b. Absorption through open tanks and fittings.
c. Oxygen permeable materials in the distribution

system.

d. Suction at pump and valve seals.

In order to ensure long product life, oxygen sources

should be eliminated. This can be accomplished by

taking the following measures:
a. Repairing system leaks to eliminate the need for

addition of make-up water.

b. Eliminating open tanks from the system.
c. Eliminating and/or repairing fittings which allow

oxygen absorption.

d. Use of non-permeable materials in the distribution

system.

e. Isolating the boiler from the system water by

installing a heat exchanger.

and eventually cracks. The presence of free oxygen in

the boiler creates a corrosive atmosphere which, if the

concentration becomes high enough, can corrode the

cast iron through from the waterside. Since neither of

these failure types are the result of a casting defect the

warranty does not apply. Clearly it is in everyone’s best

interest to prevent this type of failure. The maintenance

of system integrity is the best method to achieve less

makeup water.