BS 1170:1983

Foreword
Committees responsible
Methods
Section one. General
1 Scope
2 References
3 Definitions
4 Control of treatment ashore and afloat
Section two. Sources of water and limiting impurities
             for various groups of boilers
5 Sources of water
6 Effect of boiler plant design and operating
    conditions on required water quality
7 Effect of boiler type on required water quality
Section three. Chemical cleaning
8 General
9 Pre-commission cleaning of boilers and feed systems
10 Post-commission cleaning of boilers
Section four. Objectives of water treatment
11 General
12 Scale formation
13 Hideout
14 Corrosion
15 Steam purity and feed-line corrosion
16 Blowdown
Section five. Treatment of feed water
17 Design considerations
18 Factors under the control of the engineer
Section six. Treatment of water in the boiler
19 General
20 Chemicals
21 Limits of treatment
22 Sampling arrangements and equipment
23 Group 1 boilers
24 Group 2 boilers
25 Group 3 boilers
26 Group 4 boilers
27 Group 5 boilers
28 Group 6 boilers
Section seven. Preservation of idle boilers
29 Long term storage
30 Short term storage
Appendices
A Explanation of terms
B pH value, acidity and alkalinity
C Chemicals used in marine boiler water treatment
D Methods of test
E Preparation of reagents
F On-line instrumentation and automation
Tables
1 Boiler water, feed water and condensate
    characteristics for group 1 boilers (up to 17.5 bar)
2 Boiler water, feed water and condensate
    characteristics for group 2 boilers (17.5 bar to
    31 bar)
3 Boiler water, feed water and condensate
    characteristics for group 3 boilers (31 bar to 42
    bar)
4 Boiler water, feed water and condensate
    characteristics for group 4 boilers (42 bar to 60
    bar)
5 Boiler water, feed water and condensate
    characteristics for group 5 boilers (60 bar to 80
    bar)
6 Boiler water characteristics for group 6 boilers
    (80 bar to 130 bar)
7 Feed water and condensate characteristics for group
    6 boilers (80 bar to 130 bar)
8 Dilutions for phosphate determination
Figures
1 Sample cooling coil for multiple sampling points
2 Alternative methods of adding chemicals
3 Congruent phosphate/pH control graph
4 Maximum concentration of silica in boiler water
5 Effect of mineral acidity on pH value
6 Modified Nessler cylinder
7 Hydraulic system for sampling suspended solids

Covers sources of water and limiting impurities for various groups of boilers, pre-commission cleaning, objectives of water treatment, treatment of water before the boiler and in the boiler, preservation of idle boilers. Appendices give explanation of terms, chemicals used in marine boiler water treatment, methods of testing and list of reagents. Tables on boiler water characteristics for the six pressure ranges into which the boilers are divided.

This British Standard gives recommendations on the treatment of water for marine boilers with working pressures up to 130 bar. It applies to six groups of boilers, classified according to their operating pressures as follows (see also 17.1).

• Group 1. Boilers up to 17.5 bar
• Group 2. Boilers from 17.5 bar to 31 bar
• Group 3. Boilers from 31 bar to 42 bar
• Group 4. Boilers from 42 bar to 60 bar
• Group 5. Boilers from 60 bar to 80 bar
• Group 6. Boilers from 80 bar to 130 bar

Section 6 of the standard gives detailed information on each of these groups. This section gives recommendations for feed water and condensate as well as for the water in the boilers.

This standard is concerned with water conditions for boilers and associated plant, but is not intended to cover all details of the maintenance of equipment.