Preliminary Requirements

Safety Requirements

WARNING

YOU MUST USE THE NECESSARY CLOTHING TO GIVE YOU PROTECTION. THIS MUST INCLUDE RUBBER GLOVES AND GOGGLES.

WARNING

IF YOU GET AN AGENT OR A SOLUTION IN YOUR EYES, YOU MUST IMMEDIATELY CLEAN IT AWAY WITH A SUFFICIENT QUANTITY OF WATER FOR A LONG TIME. YOU MUST GET IMMEDIATE MEDICAL AID.

WARNING

IF YOU GET AN AGENT OR A SOLUTION ON YOUR SKIN, YOU MUST CLEAN IT AWAY WITH A LARGE FLOW OF CLEAN WATER.

WARNING

YOU MUST GET MEDICAL AID FOR ALL BURNS (THIS INCLUDES SMALL BURNS) AT THE NEAREST SURGERY OR FIRST-AID POST.

WARNING

THE SURGERY OR FIRST-AID POST MUST BE TOLD WHICH AGENT OR SOLUTION HAS CAUSED THE BURN.

WARNING

DO NOT ADD LARGE QUANTITIES OF SODIUM HYDROXIDE OR CAUSTIC SODA TO ONE PART OF THE TANK. APPLY THE CHEMICALS EQUALLY ACROSS THE SURFACE OF THE SOLUTION.

WARNING

THE BLACK OXIDE SOLUTION HEATER MUST ALWAYS BE INSTALLED ON THE SIDE OF THE TANK, ABOVE THE SLUDGE LEVEL.

WARNING

WHEN WATER IS ADDED TO THE SOLUTION IT MUST BE FULLY MIXED, TO PREVENT A WATER GAS EXPLOSION WHEN THE SOLUTION BOILS.

WARNING

IT IS THE RESPONSIBILITY OF THE OPERATOR TO OBTAIN AND OBSERVE THE MANUFACTURERS MATERIAL SAFETY DATA SHEETS FOR CONSUMABLE MATERIALS INFORMATION SUCH AS, HAZARDOUS INGREDIENTS, PHYSICAL/CHEMICAL CHARACTERISTICS, FIRE, EXPLOSION, REACTIVITY, HEALTH HAZARD DATA, PRECAUTIONS FOR SAFE HANDLING, USE AND CONTROL MEASURES AND ALSO TO TAKE LOCAL REGULATIONS INTO CONSIDERATION.

Procedure

1. SUBTASK 70-33-17-200-001 The Test and Control of the Hydrochloric Acid Pickling Solution

   1. You must change the solution when it will not remove the used black oxide layer satisfactorily.

2. SUBTASK 70-33-17-220-002 The Test and Control of the Black Oxide Solution

   1. NOTE

      This check must be done each week.

      Measure the concentration of CoMat 01-047 POTASSIUM DICHROMATE K2Cr2O7 in the solution:

      1. Use a 25 ml flask to get a 25 ml sample of the solution, then put the sample into a 250 ml flask. Flush the 25 ml flask a total of three times with CoMat 01-201 DISTILLED, DEIONIZED, DEMINERALIZED, OR REVERSE OSMOSIS (RO) WATER; then put all the used water into the 250 ml flask. Fill the 250 ml flask to the mark with distilled or deionized water and fully mix.

      2. Use a 20 ml pipet to get a 20 ml sample from the 250 ml flask. Put the sample into a 400 ml conical titration beaker, then add 50 ml of distilled or deionized water. Add 10 ml of 50 percent v/v CoMat 01-043 SULFURIC ACID H2SO4 and, from a buret, 9.5 ml of N/10 CoMat 01-054 FERR.AMMON.SULPHATE FeSO42S04 6H2O. Titrate with N/10 CoMat 01-055 POTASSIUM PERMANGANATE KMnO4 solution, to a faint purple end point. Add 0.5 ml more of the N/10 ferrous ammonium sulfate and titrate to the faint purple end point.

      3. Write down the quantity of potassium permanganate used - (A ml). Prepare a blank solution with 10 ml of 50 percent v/v sulfuric acid and 50 ml of distilled or deionized water; in a 400 ml conical titration beaker.

      4. Add 9.5 ml of N/10 ferrous ammonium sulfate and titrate with N/10 potassium permanganate solution to a faint purple end point. Add 0.5 ml more of the N/10 ferrous ammonium sulfate and titrate with the N/10 potassium permanganate solution to the faint purple end point.

      5. Write down the quantity of potassium permanganate used - (B ml).

      6. The ml of KMnO4 = B - A and the g/l of the K2Cr2O7 in the solution = (B - A) x 2.45.

      7. If the g/l of K2Cr2O7 is less than 12, add a sufficient quantity of K2Cr2O7 to the tank; to make the K2Cr2O7 concentration equal to 15 g/l.

   2. Add the same quantity of CoMat 01-252 SODIUM NITRATE NaNO3, to the tank, as that calculated for the potassium dichromate (K2Cr2O7) in step A.

   3. Supply the water continuously through a drop flow supply (which has a shield). Alternatively lower the solution temperature to 203 deg F (95 deg C), add the necessary quantity of water, then fully mix. Let sufficient quantities of water into the solution to replace that which is lost (because of the effects of evaporation). This will also control the caustic soda concentration.

   4. If the temperature at which the solution boils increases above 289 deg F (143 deg C), it is necessary to add a large quantity of water. You must let the solution temperature decrease to 203 deg F (95 deg C) before you do this. Add the water and fully mix. Increase the solution temperature until it boils at 284 deg F (140 deg C).

   5. If the temperature (at which the solution boils) decreases to less than 280 deg F (138 deg C) carefully add CoMat 01-022 SODIUM HYDROXIDE NaOH (SOLID). Do this until the temperature (at which the solution boils) increases to 284 deg F (140 deg C). Let the solution temperature cool to 140 deg F (60 deg C) before you add the CoMat 01-022 SODIUM HYDROXIDE NaOH (SOLID) according to the manual rule. Do not let the solution get on you.

   6. Let the solution temperature cool when you do not use the tank. To prevent problems, when the temperature increases to 284 deg F (140 deg C), keep the solution temperature at 140 deg F (60 deg C). Deterioration of the sodium nitrate and potassium dichromate occurs at the solution operation temperature.

   7. When it is very difficult to remove the loose particles from the part with a soft bristle brush (refer to SUBTASK 70-33-17-300-002) do as follows:

      1. Let the large quantity of unwanted material in the solution go to the bottom of the tank.

      2. Remove the clean solution from the tank.

      3. Remove the unwanted material from the tank.

      4. Put the clean solution back into the tank.

      5. Measure the depth of solution necessary to fill the tank to the correct level, then calculate the volume of solution to be used.

      6. Calculate the quantities of chemicals, necessary for the above volume.

      7. Make-up the necessary solution, as specified in SUBTASK 70-33-17-100-002.