COOLING WATER TREATMENT
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DEWT NC - Diesel Engine Water Treatment
Description
DEWT NC treatment is a powdered, nitrite-based corrosion inhibitor for ferrous and copper-bearing metals in a circulating water system. Efficient heat transfer is assured since corrosion is held to a minimum and surfaces are maintained free of deposits. DEWT NC treatment is recommended for systems with good quality distilled water makeup. Among those approving or allowing the use of DEWT NC treatment are the following major engine manufacturers:
Aktiebolaget Gotaverken MAN B&W Diesel
Aktiebolaget Lindholmens Mirrless BlackstoneLimited
Varv Mitsubishi-Kobe
A.P.E. Ltd. - W.H. Allen Mitsui Engineering &
Colt Industries Shipbuilding Co. Ltd.
Diahatsu Diesel KK Nohab
Deutz (KHD) Ruston & Hornsby Ltd.
Fuji Diesel Co., Ltd. SACM-Mulhouse
Hitachi Zosen Sulzer Brothers Limited
IHI - Sulzer Wartsila NSD
Kockums William Doxford & Sons
MaK (Engineers) Ltd.
Yanmar Diesel Engine
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Features |
Benefits |
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Effective corrosion inhibitor |
Protects ferrous and copper-bearing metals Minimizes metal oxide deposits |
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Buffered |
Stabilizes cooling water pH |
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Non-abrasive |
Does not damage standard seals, hoses or packing |
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Compatible with antifreeze |
Does not form fouling deposits when mixed with glycol |
Application and Use
System Preparation
DEWT NC treatment is an effective corrosion inhibitor for ferrous and copper-bearing metals in marine circulating cooling water systems. Because certain aluminum alloys are highly anodic, they may be difficult to completely protect. Therefore, the use of DEWT NC treatment with systems containing aluminum alloys should be discussed with a local Drew Marine representative prior to starting treatment.
In order to ensure the maximum benefits from a DEWT NC treatment program, the system should be inspected for deposits and corrosion. If the system is found to be contaminated, it must be chemically cleaned before the treatment program begins. Your Drew Marine representative can provide specific cleaning recommendations. Sacrificial anodes (magnesium or zinc) in the cooling systemshould be removed prior to adding DEWT NC treatment. These materials are not necessary with the complete chemical program in effect and, in fact, may cause undesirable deposits in the circulating water systems.
The recommended treatment level of DEWT NC diesel engine water treatment is 3,000-4,300 ppm. This represents an initial dosage of 3.2 kg per ton of circulating water.
Dosage
The system should be filled with distilled water and where freeze protection is necessary, the proper amount of glycolbased antifreeze should be added. Begin circulating the system and add DEWT NC diesel engine water treatment at an initial dosage of 3.2 kg per ton of system water capacity. Circulate for 30 minutes after addition to ensure good distribution and the establishment of a protective film. DEWT NC diesel engine water treatment may be used with waters that have hardness contamination, provided the total hardness levels are below 170 ppm or as otherwise recommended by the engine manufacturer, whichever is less. The chloride level in the cooling system should be limited to 100 ppm or as otherwise recommended by the engine manufacturer, whichever is less.
Testing Procedure
The proper concentration of DEWT NC diesel engine water treatment can be maintained using the CWT Titrets1 or the DEWT NC Test Kit. Tests should be conducted to confirm that a minimum DEWT NC treatment concentration of 3,000 ppm is present. Testing will also confirm that you have not exceeded the recommended maximum of 4,300 ppm of DEWT NC treatment. Normally, testing once each week is satisfactory; however, when makeup addition to the system is large or unusual changes are noticed, testing frequency should be increased. Contact your Drew Marine representative for the Cooling Water Treatment Testing Control and Dosage chart for more detailed information.
Typical Physical Properties
Appearance: White to pale yellow free-flowing powder
Density: 70 lbs.ft3 (1.12 g/cm3)
pH/Concentration:10.0 (1%)
Packaging
DEWT NC diesel engine water treatment is available in 25 Kg containers.
Important Information
Ashland maintains Material Safety Data Sheets on all of its products. Material Safety Data Sheets contain health and safety information for your development of appropriate product handling procedures to protect your employees and customers.