Stainless Steel Passivation Line With RO RinsesAdaptable treatments line for the passivation of Stainless Steels using either organic or mineral acid's. The system comprises of: The

Home > Surface Treatment Process Plant & EquipmentElectroplating & treatment lines >

Stainless Steel Passivation Line With RO Rinses

Stock Code: TV185Model: Passivation lineYear of Manufacture: 2012New or Used: Used (Second Hand)Work Envelope (WxDxH mm): 450 x 450 x 900Process Stages: MultipleOther Info: Stand mounted and bundedExternal Dimensions (WxDxH): 1140 x 4400 x 1250 (4200)

Adaptable treatments line for the passivation of Stainless Steels using either organic or mineral acid's.

The system comprises of:

The Marketplace for Surface Technology.New and Used Process Equipment & Machinery.

Riley Industries LtdA subsidiary of Barry Riley & Sons Ltd. Director: M P A Riley, Secretary: D Hemming

Registered in England no. 1965748

Page 1/5

https://www.rileysurfaceworld.co.uk

https://www.rileysurfaceworld.co.uk/surface_treatments.asp

https://www.rileysurfaceworld.co.uk/surface-treatment-electroplating.asp


Stainless Steel Passivation Line With RO Rinses1 x Steel Alkali heated tank, 450 x 450 x 900 mm with digital temperature control1 x Polypropylene plastic townwater rinse, tank 450 x 450 x 900 mm1 x Polypropylene plastic heated acid tank, 450 x 450 x 900 mm with digitaltemperature control2 x Polypropylene plastic RO water rinse, tank 450 x 450 x 900 mm1 xadditional Polypropylene plastic tank, 400 x 500 x 600 mm1 x Pressure booster circulation pump for sprayed ROwater rinsing,1 x Twin legged extraction system with fan.1 x Full length Polypropylene bund tank1 x Drain waterbreak tank1 x Merlin Reverse osmosis water generator and water softener, for the production of stain free neutralfinal rinsing.

MERLIN Reverse Osmosis unit removes from your tap water Typical removal % rates: Sodium 99 Calcium 99 Magnesium99 Potassium 98 Iron 99 Manganese99 Aluminium 99Ammonium97 Copper 99 Nickel 99 Zinc 99 Strontitan 99 Cadmium 99 Silver 98 Mercury 98 Barium 99 Chromium 99Lead 99 Chloride 99 Bicarbonate98 Nitrate 97 Fluoride 98 Silicate 98 Phosphate 99 Chromate 99 Cyanide 95Sulphate 99 Thiosulfate 99 Ferro cyanide97 Bromide 98 Borate 50 Arsenic 99 Selenium 99 Bacteria 99 Protozoa 99Amoebic Cysts99 Giardia 99 Asbestos 99 Sediment/Turbidity99 Perfluorooctane Sulphonate (PFOS) 99

MERLIN filter stages1st Stage: Merlin Sediment filter 2nd Stage: Water is pushed through 2 Merlin membranes that separate the pure H20 from the contaminated H20.The contaminated water, approx 70%,is then sent down the drain while the pure water is passed onto the finalstage. Final Stage: Water passes through a final carbon fillter and flows to its rinsing destination.

Technical specificationPermeate Flow Rate Min 1.5 LPM Max 3.78 LPM @ 80F TDS Rejection Min 90% Max 99% Max Daily production rate 2700 Litres Per Day UK Water Inlet Pressure required Min 40 PSI Max 80 PSI

Passivation processes

Passivation remains a critical step in maximising the essential corrosion resistance of parts and componentsmachined from stainless steels. It can make the difference between satisfactory performance and premature failure.

Passivation is a post-fabrication method of maximising the inherent corrosion resistance of the stainless alloy fromwhich the work-piece was produced.

A clean, freshly machined, polished or pickled stainless steel part automatically acquires this oxide film fromexposure to oxygen in the atmosphere. Under ideal conditions, this protective oxide film completely covers allsurfaces of the part.

Passivation is needed to maximise the natural corrosion resistance of the stainless steel. It can remove surfacecontamination, such as particles of iron-containing shop dirt and iron particles from cutting tools that can form rust oract as initiation sites for corrosion. Passivation also can remove sulphides exposed on the surface of free-machiningstainless alloys.




Page 2/5





Stainless Steel Passivation Line With RO RinsesA two-step procedure can provide the best possible corrosion resistance: 1. cleaning, a fundamental, but sometimesoverlooked procedure and 2. an acid bath, or passivating treatment.

Cleaning First

Cleaning should always come first. Grease, coolant or other shop debris must be thoroughly cleaned from thesurface to obtain the best possible corrosion resistance. Machining or other shop dirt can be wiped carefully off thepart. A commercial degreaser or cleanser may be used to clean off machining oils or coolants. Foreign matter suchas thermal oxides may have to be removed by grinding, or by methods such as acid pickling.

Passivating Baths

After thorough cleaning, the stainless steel part is ready for immersion in a passivating acid bath. Any one of threeapproaches can be used—nitric acid passivation, nitric acid with sodium dichromate passivation and citric acidpassivation. Which approach to use depends on the grade of stainless steel and prescribed acceptance criteria.

More resistant chromium-nickel grades can be passivated in a 20 percent-by-volume nitric acid bath. Less resistantstainless grades can be passivated by adding sodium dichromate to the nitric acid bath to make the solution moreoxidising and capable of forming a passive film on the surface. Another option, used in place of nitric acid plussodium dichromate, is to increase the concentration of nitric acid to 50 percent-by-volume.

Nitric Acid Passivation of Stainless Steels—Chromium-Nickel Grades (300 Series)—Grades with 17% Chromium or more (except 440 Series)20% by vol. nitric acid at 120/140°F (49/60°C) for 30minutes—Straight Chromium Grades (12-14% Chromium)—High Carbon-High Chromium Grads (440 Series)—Precipitation Hardening Stainless20% by vol. nitric acid + 3 oz. per gallon (22 g/liter) sodium dichromate at120/140°F (49/60°C) for 30 minutesor50% by vol. nitric acid at 120/140F (49/60°C) for 30 min. Passivation forFree-Machining Stainless Steels Including AISI Types 420F, 430F, 440F, 203, 182-FMand Carpenter Project 70+® Types 303 and 4161.5% by wt. sodium hydroxide at 160/180°F (71/82°C) for 30minutes.2.Water rinse.3.20% by vol. nitric acid + 3 oz. per gal. (22 g/liter) sodium dichromate at 120/140°F (49/60°C) for 30 minutes.4.Water rinse.5.5% by wt. sodium hydroxide at 160/180°F (71/82°C) for 30 minutes.6.Water rinse.Free-Machining Stainless Grades

To effectively passivate the free-machining stainless steels, the A-A-A (alkaline-acid-alkaline) process thatneutralises trapped acid. This method of passivation can be accomplished in less than 2 hours.

Here is the step-by-step procedure:




Page 3/5





Stainless Steel Passivation Line With RO RinsesAfter degreasing, soak the parts for 30 minutes in a 5 percent solution of sodium hydroxide at 160°F to 180°F (71°Cto 82°C). Then rinse the part thoroughly in water. Next, immerse the part for 30 minutes in a 20 percent-by-volumenitric acid solution containing 3 ounces per gallon (22 g/liter) of sodium dichromate at 120°F to 140°F (49°C to 60°C).After removing the part from this bath, flush it with water, then immerse it in the sodium hydroxide solution foranother 30 minutes. Rinse the part again with water and dry it, completing the A-A-A method. The benefits of thismethod are shown in below.

Process 1

Water rinse.• Clean/degrease.Passivate.Water rinse.Dry.

Process 2

Clean/degrease in 5% by weight sodium hydroxide at 160 to 180°F (71 to 82°C) for 30 minutes.Waterrinse.Passivate.Water rinse.Neutralize in 5% by weight sodium hydroxide at 160 to 180°F (71 to 82°C) for 30minutes.Water rinse.Dry.

Citric acid passivation has become increasingly popular with manufacturers who want to avoid the use of mineralacids or solutions containing sodium dichromate, along with the disposal problems and greater safety concernsassociated with their use. Citric acid is considered environmentally friendly in every respect.

Although citric acid passivation offers attractive environmental advantages, shops having success with mineral acidpassivation and suffering no safety issues might want to stay the course. There may be no real need to change ifthose users have a clean shop, well-maintained and clean equipment, coolant free of iron-containing shop dirt, and aprocess that yields good results.

Passivation treatment in citric acid baths has been found useful for a large number of stainless steel families,including several individual stainless grades, as summarised below. The conventional nitric acid passivation methodsare also included for convenience. Note that the older nitric acid formulations are in volume percent, while newercitric acid concentrations are in weight percent.

The passivation treatment varies depending on chrome content and machinability characteristics of the grades ineach family.

Procedures for passivating commonly used free-machining and non-free-machining stainless steels in citric or nitricacid solutions require different processes. Details about the choice of processes are given in Figure 5.StainlessFamilyExample Stainless Steels% Cr10% by weight Citric Acid - passivated 30 minutes as belowPercent Nitric Acid -passivated 30 minutes at 120/140°F°FpH(a)Process (b)Volumn %(c)Process(b)AusteniticType 304/304L

Type 316/316L

Custom Flo 302HQ

Type 305

Type 304/304L




Page 4/5





Stainless Steel Passivation Line With RO Rinses

Nitrogen strengthened

15.0-23.5150 120%1Martensitic-PHCustom 630 (17Cr-4Ni)

Custom 450

Custom 455

Custom 465T

15Cr-5Ni

11.017.5150 120% + Na2Cr2O71FerriticType 430> 16150 120% + Na2Cr2O71FerriticType 409<12180-200 120% +Na2Cr2O7use care: low Cr1MartensiticType 410

Type 420

TrimRite

< 15120-130 220% + Na2Cr2O71Austenitic-FMType 30317-19150 220% + Na2Cr2O72Ferritic-FMTypes 430F &430FR> 16NANANA20% + Na2Cr2O72Ferritic-FMChrome Core® 18-FM> 16100 2NANAFerritic-FMType409Cb-FM< 1311052

20% + Na2Cr2O7Use care: low Cr

2Martensitic-FMType 416< 1311052Preferred vs. citric20% + Na2Cr2O72

View Stainless Steel Passivation Line With RO Rinses on our web site athttps://www.rileysurfaceworld.co.uk/machines/27488.htm

PHOTOGRAPHS TAKEN PRIOR TO REFURBISHMENT.




Page 5/5




https://www.rileysurfaceworld.co.uk/machines/27488.htm

Documents

Stainless Steel Passivation Line With RO RinsesAdaptable treatments line for the passivation of Stainless Steels using either organic or mineral acid's. The system comprises of: The