Chapter  7—AUXILIARY  MACHINERY Table   7-5.—Disodium   Phosphate   Dosage   For   Natural   Circulation   Auxiliary   Boilers   (Disodium   Phoshate,   Anhydrous Na₂HPO₄) Corrected DSP Dosage = Boiler Water Factor Phoshate (ounces/gallons) ppm  (mg/L) 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250 260 270 280 X 0.058 X 0.056 X 0.054 X 0.052 X 0.050 X 0.048 X 0.046 X 0.044 X 0.042 X 0.040 X 0.038 X 0.036 X 0.034 X 0.032 X 0.030 X 0.028 X 0.026 X 0.024 X 0.022 X 0.020 X 0.018 X 0.016 X 0.014 X 0.012 X 0.010 X 0.008 X 0.006 X 0.004 X 290 0.002 X (Enter) Boiler Water Volume  for Chemical Treatment (gallons) (Calculate) ounces  of DSP Required to raise Phosphate to 300 ppm (300 mg/L) = = = = = = = = = = = = = = = = = = = = = = = = = = = = = 1 ounce - 28.35 grams 1 gallon - 3.785 liters DSP - Disodium Phosphate dosages  for  the  completed  dosage  tables  are described  below: 1.  Determine  the  alkalinity  and  phosphate concentrations in the boiler water from sample results. 2.  Locate  the  boiler  water  alkalinity  in  the first  column  of  table  7-4.  Then  read  across to  the  weight  of  TSP  required  for  the  correct volume. (Use table 7-6 for the vessels listed ear- lier  in  the  chapter.)  Enter  this  weight  in  the log. 7-13