DREWPLEX OX corrosion inhibitor is an all-volatile, liquid, catalyzed oxygen scavenger for use in low-, medium- and high-pressure steam generating systems. DREWPLEX OX corrosion inhibitor controls ferrous and non-ferrous corrosion in feed water, boilers, steam and condensate lines with the use of DEHA as the oxygen scavenger.

In addition to scavenging oxygen, DREWPLEX OX corrosion inhibitor passivates metal surfaces through the formation of protective oxide films in order to minimize iron and copper deposits in the boiler. DREWPLEX OX corrosion inhibitor may be used with DREWPLEX AT boiler water treatment, standard treatment for low-pressure steam generating systems (0-32 bar), standard treatment for medium-pressure steam propulsion vessels (32-60
bar), and our ULTRAMARINE℠ boiler water treatment program for high-pressure steam generating systems (60-84 bar). When coupled with DREWPLEX AT boiler water treatment, DREWPLEX OX corrosion inhibitor supports the most modern, safe and effective approach to a boiler water treatment program.


  • Dosage, Testing and Control

The continuous dosage of DREWPLEX OX corrosion inhibitor depends on the amount of dissolved oxygen in the feedwater. The colder the feedwater, the more dissolved oxygen there will be. Keep the feedwater temperature as close to 90° C, or higher, if possible. For starting up a new system, an estimated initial dosage of DREWPLEX OX corrosion inhibitor is 100 – 300 mls per day. Daily testing of DEHA in the feedwater using the
DREWPLEX OX ampoule test kit determines the necessary dosage to maintain the concentration within the specified control range. If the system has been poorly passivated, the initial system “demand” for DREWPLEX OX corrosion inhibitor may require a higher dosage for the first few weeks until the system comes to stabilization.

Slug dosing and/or improper control of the DEHA concentration will not provide adequate protection of the boiler system and may lead to accumulation of ammonia in the condensate with possible corrosion of copper alloy tubes.

  • Feed Points

For low-pressure steam generating systems, when there is feedwater recirculation, dose DREWPLEX OX corrosion inhibitor continuously after the feedwater recirculation off take. Diluted DREWPLEX OX corrosion inhibitor may be fed with diluted DREWPLEX AT boiler water treatment using the DREWTM beta metering system. For low-pressure steam generating systems using standard treatment, continuously dose diluted DREWPLEX OX corrosion inhibitor with diluted SLCC-A™ corrosion inhibitor using the DREW beta metering system to the feedwater line downstream of the feedwater recirculation off take. If there is no feedwater recirculation, dose continuously to the feed pump suction. If a gravity feed flowmeter arrangement is used, the dosage point should be to the feed or cascade tank. The chemical feed line should extend at least one meter below the water surface to avoid volatilization of the product. For steam systems with deaerators, DREWPLEX OX corrosion inhibitor should be continuously dosed by pump to the storage section of the deaerator or to the feed pump suction.

  • Layup

DREWPLEX OX corrosion inhibitor can also pro-vide corrosion protection for boilers during wet layup. For details, consult a Drew Marine representative.


AppearanceClear, pale yellow to dark brown
Specific Gravity @ 25° C1.005
Flash Point (PMCC)62° C
Freezing Point-2.2° C
pH (Neat)8.3
Freeze/Thaw StabilityComplete
Evaporation rate>1 Ether=1
Flammability Combustible
Solubility in waterMiscible
Relative density (Water = 1)1.005
NOTE: Always wear the appropriate personal protective equipment when using this product.


DREWPLEX OX corrosion inhibitor is available in 25-liter containers (PCN 6623400).

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