ENGINEMAN 1 & C
freshly filled, chemically treated boiler, prior to
light off, is not representative and is therefore
meaningless. The freshly filled and treated boiler
shall be steamed immediately but not later
than 24 hours after being filled. Preferably, the
boiler should not be filled unless it is expected
to be fired within 24 hours. If the boiler can-
not be steamed within 24 hours, it should be
placed under dry layup in accordance with chap-
ter 221, Boilers, Naval Ships’ Technical
Manual.
ALKALINITY AND PHOSPHATE.—Since
the addition of TSP to raise the alkalinity
also raises the phosphate, the control of alkalinity
and phosphate are linked. The DSP provides
additional phosphate as needed. The boiler
water volume for chemical treatment must be
determined as described earlier. Using this
volume, the dosages of TSP and DSP are
calculated. Table 7-4 gives the TSP dosage fac-
tor (ounces per gallon) for all values of alkalinity.
The boiler volume is multiplied by the factor and
the dosage of TSP is entered to the nearest one-
half ounce in the appropriate space. The increase
in phosphate due to TSP is given in the last
column. The DSP dosages are calculated similarly
using the DSP factors (ounces per gallon) given
in table 7-5. TSP and DSP dosages for the aux-
iliary boilers are given in tables 7-6 and 7-7. The
procedures for determining the chemical treatment
Table 7-4.—Trisodium Phosphate Dosage For Natural Circulation Auxiliary Boilers (Trisodium Pbosphate, Dodecahydrate,
Na3PO412H20)
Boiler water
Alkalinity
epm (meg/L)
0.1
0.095
X
=
0.2
0.090
X
=
0.3
0.085
X
=
0.4
0.080
X
=
0.5
0.075
X
=
0.6
0.070
X
=
0.7
0.065
X
=
0.8
0.060
X
=
0.9
0.055
X
=
1.0
0.050
X
=
1.1
0.045
X
=
1.2
0.040
X
=
1.3
0.035
X
=
1.4
0.030
X
=
1.5
0.025
X
=
1.6
0.020
X
=
1.7
0.015
X
=
1.8
0.010
X
=
1.9
0.005
X
TSP Dosage
Factor
(ounces/gallon)
X
(Enter)
Boiler Water
Volume for
Chemical
Treatment
(gallons)
=
(Calculate)
Ounces of TSP
required to raise
alkalinity
to 2.0 epm
Phosphate
Correction
180
170
160
150
140
130
120
110
100
90
90
80
70
60
50
40
30
20
10
=
1 gallon = 3.785 liters
1 ounce = 28.35 grams
TSP - Trisodium Phosphate
7-12
