Cooltreat NCLT

Cooltreat NCLT

COOLTREAT NCLT is a specially formulated liquid corrosion and scale inhibitor for closed circuit cooling water systems.

Product description


COOLTREAT NCLT is a nitrite-, borate- and organics-based corrosion inhibitor suitable for all types of engines and other closed recirculating water systems.

Directions for use

Determine the quantity of treatment required for the system from the product dosage chart.
COOLTREAT NCLT should be dosed to the system by means of a VECOM MARINE dosing system.
The dosing position should be where the circulation is at the highest. Do not add to expansion tank if there is little or no circulation.

Systems contaminated with oil and/or scale should be cleaned before applying COOLTREAT NCLT treatment. Use SEACLEAN VOYAGE for degreasing and DESCALING LIQUID EXTRA for descaling operation.

Water quality is one of the most important issues in today’s treatments. Always use good quality demineralized water. Under no circumstance should cooling water be mixed with shore water or potable water.

Shore water or potable water has far too many impurities like silica, bicarbonates and other minerals that can cause scale and corrosion to the cooling water system. In order to treat the closed cooling water system it is vital to use nothing but demineralized/evaporator water, or reverse osmosis water.

Dosage and control

The effective control range of COOLTREAT NCLT is 1000 ppm of NO2. To maintain adequate reserves, we recommend a nitrite reserve of 1500 ppm. The nitrite level should not be allowed to fall below 1200 ppm.

Initial dosage is 10.3 l of COOLTREAT NCLT for every ton of cooling water. Maintenance dosages are based on the nitrite concentration shown in the product dosage chart.



Nitrite (NO2) [ppm]


Initial dose














1500 – 2000

The condition of the cooling water treated with COOLTREAT NCLT, should be within the following recommendation:

Nitrite: 1200 – 1500 ppm
Chloride: Below 100 ppm Cl
Hardness: Below 180 ppm CaCO3
pH: 8.3 – 10

Use the VECOM MARINE TEST KIT NITRITE to determine the COOLTREAT NCLT level. If there are no leaks and an apparent drop in nitrite value is observed in the system, this could be due to bacterial contamination. Contact your VECOM MARINE representative for assistance.

All competitors’ nitrite/borate-based water treatments are compatible with COOLTREAT NCLT, but allow old product to drop to lowest limit before dosing the VECOM MARINE product. It is only necessary to drain the cooling water when the competitor’s product has a colour coder, or pH colour changer in it.

Note: COOLTREAT NCLT will slowly remove sludge and other residues during the first period of operation. This can result in cloudy water, which will clarify after blowing down small quantities of water.

Please consult your VECOM MARINE representative for the correct procedure of changing to COOLTREAT NCLT.

Standard packing

COOLTREAT NCLT is usually available in plastic cans of 25 l and plastic drums of 200 l.

Features & Benefits

  • Easy to use, easy to dose, liquid cooling water treatment
  • Highly effective anodic inhibitor treatment, protects ferrous and non-ferrous metals
  • Deposits a microscopic protective film on surfaces
  • Built-in pH buffering compounds
  • Approved by major engine manufacturers
  • Controls formation of hard scale deposits
  • Will not damage seals, glands, packing, hoses and gaskets
  • Compatible with all types of glycol based antifreeze
  • Prevents cavitation or erosion
  • Simple to test and control
  • Can be used in all types of closed cooling water systems

Wärtsilä approval
The engine manufacturer approval for Cooltreat NCLT by Wärtsilä can be downloaded here.

MAN approval
The engine manufacturer approval for Cooltreat NCLT by MAN can be downloaded here.

This information is not to be taken as a warranty or representation for which Vecom Marine assumes legal responsibility.
The information is offered solely for your consideration, investigation and verification.