<1. General Information>
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IM 12Y18A03-01EN
1st Edition : Oct. 04, 2019-00
• Self diagnostics:
• Ease of maintainability.
• Password protection:
• Security and peace of mind for your operation.
• Auto-ranging electronics with an easy to read backlit LCD display:
• Analyzer determines the best range.
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Application Modes
The versatility of the WE430 Hydrazine analyzer allows the operator to set the analyzer to read
hydrazine, depending on the oxygen scavenger to be measured. Refer to Section 3.1, Use of the
Setup Mode for instructions on how to set the analyzer to read hydrazine.
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Hydrazine Application
Hydrazine Measuring Range: 0 ppb to 200 ppb as hydrazine
In high pressure boiler systems, hydrazine is added to react with dissolved oxygen present in the
system and a small amount of residual hydrazine is left behind. The residual hydrazine ensures
that small amounts of dissolved oxygen that enters the system through leakage will be removed.
Residual hydrazine should be carefully monitored to prevent costly overdosing.
Excess hydrazine may also decompose into ammonia, which increases sample alkalinity and
attacks copper alloy components. Efficient control of hydrazine depends on maintaining a
predetermined safety zone – typically 10 to 50 ppb.
1.1
Principles of Operation
The sample enters the WE430 Hydrazine analyzer and passes through the inlet valve, bypass/
needle valve, inlet filter, pressure regulator, flow meter and into the restrictor tubing. The sample
then passes through the fluid connector block into a reagent bottle and through a diffusion tubing
assembly where pH adjustment takes place and iodine is added. The pH-adjusted sample then
flows back through the connector block into the reagent mixing loop where the oxygen scavenger
in the sample mixes with iodine reagent to form iodide. The sample then passes the iodide
electrode, reference electrode and temperature probe and flows into an atmospheric drain via the
diverter valve.