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Oil Boil out and Passivation of fresh metal surfaces
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Author:  060 Hogger [ Fri Mar 30, 2012 10:19 pm ]
Post subject:  Oil Boil out and Passivation of fresh metal surfaces
Oil Removal and Passivation of a boiler and piping

These materials are alkaline powders, and require safe handling.
Read the package labels.

You don't have to have softened water, but it helps the process work better.
Some people like to use strong washing detergents.
This is fine, and helps with oil and grease removal,
but not a substitute for the Alkaline Passivation

Take the safety valve or whistle off the boiler.
Have a connection set-up to add some water to the boiler from the bottom or middle.

Pipe up a full-size vent line from the temporarily open connection
to a safe location that can accept the rapid discharge of hot,
soapy, oily and alkaline water. ( It’s gonna make a mess ! )

Add water to the boiler.
While adding, also add this chemical batch.
It is sized for a 100 gallon boiler, multiply proportionally to suit your own boiler's capacity,
chuck full to overflowing. If you don't know this, estimate using geometry, 8.4 gallons per cubic foot.
It is better to have a strong dose at this time, rather than a weak dose.
The objective is to get the water pH between 10 and 11.

1. Sodium Carbonate, a.k.a. Soda Ash.This is essential. 2 Lbs per 100 gallons.
This is available at a grocery store laundry section or from a pool store ( pH up ).

2. Tri Sodium Phosphate, a.k.a. TSP, 2 Lbs per 100 gallons. This is optional.
This can be found in a good painting supply store.

3. Build a slow fire and hold the boiler at low boiling for at least an hour.
The alkali, heat and circulation will be converting the oil to primitive soap

4. Keep the boil going and deliberately overflow some of the hot soapy water out of
the top of the boiler.

5. Now let the fire die out.

6. Drain the boiler hot and wash it down thoroughly with clean water from top to
bottom and front tubesheet toward the mud ring and bottom cleanouts.

7. Repeat this, especially if there is some remaining oil sheen visible on the drain water.
Once no sheen or milkiness of the water is visible, the process is completed.

8. The boiler is now ready for steam service. Restore normal piping connections.
If it is not going to be steamed immediately, it needs to be dried out
and placed into proper dry layup.

TSP is not very soluble in cold water.
I strongly advise mixing it up in 100 degree F water.
Before adding it into the top of the boiler, have about a third to half
of the water in before you add these chemicals,
then add water to the top, just below the steam dome or dry pipe outlet.

This may not be readily available in large urban areas,
due to concerns over waste water and stream quality.
TSP is optional, but recommended for best results.
It would be found in the painting preparation section, as a pre-cleaner.
The “TSP Substitute” is typically Soda Ash with some detergents.
Don't bother with that.
If you really need some real TSP, and can't find it, contact me and I'll send some.
It is also available on-line, I've found it on various on-line markets.

The alkali is cleaning oils and greases off the surfaces.
If practical, backflow some of this water through the feedwater connections,
even back to the feed tank.
If your feed tank might have oil in it, obviously, it should also be sparged out
with a steam lance and this solution.
Don't use the feed tank until it has been cleaned.

When you do refill the boiler, add treatment chemical ( see below )
as you are filling, and steam the boiler the same day if possible,
to drive off the oxygen and equally distribute the chemical treatment.

Boiler preservation and Preventive Maintenance is not a Once and Done deal.
Now that you have a good start, you must continue the process,
by following a reputable water treatment program.
Otherwise, Acids, Chlorides, Dampness and Oxygen will eat your boiler.
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