CELCO Quality Manual and Procedures Revision Notes
Revision A: Dated – May 16, 1997
Para 2.3.1 – Added to read: “Structural and Small Components – Where size and
volume permits, the parts immersed in a solution, containing 25-45% by volume
of nitric acid (NH03). An addition of Hydro Fluoric acid (HF) may be used as an
activator of solution. Parts shall be processed for a minimum of 30 minutes at a
temperature range between 70-90 degrees F (21-32 degrees C).
Para 2.3.2 – Added to read: “Large Vessels and Structure – Due to high volume
of components it will be permissible to use either a surface flooding procedure,
which constantly floods the surface with the same strength of solution as
described in paragraph 2.3.1. This process exposed the surface to the same fluid
at a constant rate and also washes the surface simultaneously pr a paste solution
which is a gel material that adheres to the surface and passivates the material at a
slower rate.
Para 6 – Removed Applicable Specifications and Standards List.
Revision B: Dated – October23, 2008
Add approval signatures and dates.
Para 2.3.2 – Revise to read: Large Vessels and Structure – Due to high volume
of component it will be permissible to use either a surface flooding procedure,
which constantly floods the surface with the same strength of solution as
described in paragraph 2.3.1. This process exposes the surface to the same fluid
at a rate and also washes the surface simultaneously. An alternate process that
could be used is a Pickle & Passivation Gel applied through a spray or with a
brush of compatible material. This gel consists of a mixture of Nitric & (HF)
along with a gel carrier that is designed to allow the product to adhere to the
surface for an extended duration until rinsed. Gel materials may need to be
applied for a duration of 15 to 60 minutes or as required for adequate results
before rinsing. Initial chemical can be removed by wiping or rinsing as described
in section 2.4.
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1. SCOPE –
This specification covers the treatment, guidance and precautions for cleaning and
descaling austenitic (300 series) stainless steel parts, components, equipment and systems
using nitric acid (NHO3) solutions.
2. REQUIREMENTS –
2.1 Material – Commercial quality chemicals and reagents used for descaling and
passivation shall be used where possible.
2.2 Pretreatment – The surface of the parts shall be free of oil, grease, rust, scale
and other foreign matter and shall have no harmful effect on material properties.
2.3 Passivation treatment – The parts shall be completely immersed in a solution
containing 25 – 45 percent by volume of nitric acid (NH03) 42 degrees Baume’.*
An additive of Hydro Fluoric acid (HF) may be used as an activator of the
solution.*** Parts shall be processed for a minimum of 30 minutes at a
temperature range between 70-90 degrees F (21-32 degrees C).*
Para 2.3.1 – “Structural and Small Components – Where size and volume
permits, the parts will be immersed in a solution, containing 25 – 45% by
volume of nitric acid (NH03). An addition of Hydro Fluoric acid (HF)
may be used as an activator of solution. Parts shall be processed for a
minimum of 30 minutes at a temperature range between 70-90 degrees F
(21-32 degrees C).
Para 2.3.2 – Large Vessels and Structure – Due to high volume of
component it will be permissible to use either a surface flooding
procedure, which constantly floods the surface with the same strength of
solution as described in paragraph 2.3.1. This process exposes the surface
to the same fluid at a constant rate and also washes the surface
simultaneously. An alternate process that could be used is a Pickle &
Passivation Gel applied through a spray or with a brush of compatible
material. This gel consists of a mixture of Nitric & (HF) along with a gel
carrier that is designed to allow the product to adhere to the surface for an
extended duration until rinsed. Gel materials may need to be applied for a
duration of 15 to 60 minutes or as required for adequate results before
rinsing. Initial chemical can be removed by wiping or rinsing as described
in section 2.4.
2.4 Water rinse – Immediately after removal from the passivation solution, the
parts shall be thoroughly rinsed in cold potable water.
2.4.1 Second water rinse – Immediately after the first water rinse, the
parts shall be thoroughly rinsed with a second potable water rinse.
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2.4.2 De-ionized water rinse – The parts shall be thoroughly rinsed with
de-ionized water to remove residual halogens from the parts.
2.5 Finish – The passivated parts shall exhibit a chemically clean surface and
shall not show any pitting, etching or frosting. A slight discoloration is allowed.
3. TESTING**
3.1 The passivated parts shall be tested by using a potassium ferricyanide – nitric
acid solution. The solution shall be sprayed on a sample piece of each batch and
shall show no staining after 30 seconds of exposure to the solution. Each test
shall be recorded and shall be filed with the inspection report to the customer.
4. PREPARATION FOR DELIVERY
4.1 The passivated parts shall be packaged in a manner which shall afford
protection of the part from excess exposure during transit.
5. CERTIFICATION
5.1 A letter of certification shall be transmitted to the customer indicating the
passivation procedure and the dates which the passivation was performed.
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