---
title: "Rich Amine Corrosion"
slug: "rich-amine-corrosion-1"
updated: 2026-10-27T23:12:43Z
published: 2026-10-27T23:12:43Z
canonical: "ims-handbook.cenosco.com/rich-amine-corrosion-1"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://ims-handbook.cenosco.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Rich Amine Corrosion

## Summary

Rich Amine Corrosion is a general or localised form of corrosion, affecting primarily carbon and low-alloy steels, though austenitic stainless steels are not fully immune. Aqueous solutions containing alkanolamines are commonly used in treating processes to remove acid gases, primarily H2S and CO2, from various gas or liquid hydrocarbon streams.

### Detailed Guidance

For detailed Guidance, see the attached PDF. A summary of the information, as it pertains to use in IMS is shown below.

[PDF document](https://cdn.document360.io/e492a0e0-a4ba-4aca-8fc6-76b95f91fdf3/Images/Documentation/CEN.16.10662 - Rich Amine Corrosion(1).pdf?sv=2026-02-06&spr=https&st=2026-10-28T14%3A21%3A33Z&se=2026-10-28T15%3A21%3A33Z&sr=c&sp=r&sig=zey6ja%2BDJP0r4Vpyt2RtZe6twMOMwMQz4jcEm1B4r3s%3D)

<editor360-custom-block data-preprocessing="true" data-sanitizationtags="a"><h2><a></a><a></a>Parameters affecting IOW – Step 2</h2></editor360-custom-block>

See [Step 2](/v414/docs/step-2-identify-threats-and-barriers-define-the-cl-1).

See below the relevant parameters affecting Rich Amine Corrosion severity and, also, an indication of those that should be included in the IOW. See also a generic IOW Table for Rich Amine Corrosion Loops.

<editor360-custom-block data-preprocessing="true" data-sanitizationtags="a"><p><a></a>Rich Amine Corrosion Parameters affecting severity &amp; IOW.</p></editor360-custom-block>

| Parameter | Influence | IOW |
| --- | --- | --- |
| Material | Carbon and low alloy steels |  |
| Amine Concentration (wt%) | Determine the amine concentration in the Equipment/ piping. Due to vaporization of water, a local increase in amine concentration may need to be considered in evaluating the corrosion of some reboilers and reclaimers. | Yes |
| Acid Gas Loading (mole acid gas/mole active amine) | Determine the acid gas loading in the amine. If analytical results are not available, it should be estimated by a knowledgeable process engineer. | Yes |
| Velocity (m/s; ft/s) | Determine the maximum velocity of the amine in this Equipment/piping. Note: If required for monitoring purposed, requires recalculation into (mass) flow. |  |
| Heat Stable Amine Salt (HSAS) | In MEA and DEA, "HSAS" represents the normal family of amine degradation products. In MDEA "HSAS" refers to organic acid contaminants, mainly formate, oxalate, and acetate. Note: Concentration: MEA and DEA (£ 2, 2-4 or > 4wt.%); MDEA (< 500, 500-4000 or > 4000 ppmw) | Yes |
| Maximum Process Temperature (°C; °F) | Determine the maximum process temperature. In reboilers and reclaimers, tube metal temperatures may be higher than the bulk process temperature. Note: Absorber column typically below 88°C (190°F). | Yes |

Generic IOW Table for Rich Amine Corrosion Loops:

| Equipment/ Stream / Location (Tag) | Parameter | Measurement unit | Typical measurement frequency | Limit Category (and Type) |
| --- | --- | --- | --- | --- |
| Absorber bottom | Maximum acid gas loading | molacid/molamine | Typically, once a day | Standard / Monitoring (Max.) |
| Absorber bottom temperature calculated from the temperature measured just before the let-down valve. | Temperature | °C | Continuously | Standard (Max.) |
| Rich solvent | Flow rate | m/s | TBD / Site specific (e.g., depends on stability of the operation) | Monitoring (Max.) |
| Rich solvent | Flow rate | m/s | TBD / site specific | Monitoring (Min) |
| Rich amine: Lean-rich exchanger tubes and piping downstream Lean-rich exchanger | Temperature | °C | TBD / Site specific; preferably continuous | Standard / Monitoring (Max.) |
| Lean amine | Solvent strength | wt.% | Typically, once a day (depends on frequency of fluctuations of the solvent strength) | Standard / Monitoring (Max.) |
| Lean amine | Chloride content | ppmw | TBD / Site specific | Monitoring (Max.) |
| Lean Amine | pH | - | TBD / Site specific / typically 3 times a week (but much more frequent than the "fingerprint" or "Huntsman" analyses). | Standard / Monitoring (Min.) |
| Lean Amine | Maximal content of heat stable amine salts (HSAS). | wt.% on total solvent | Site specific but recommended at least once per quarter and additional when the pH IOW is on or nearing the limit. | Monitoring (Max.) |
| Lean Amine | Maximal Total Suspended Solids (TSS) | ppmw | TBD / Site specific | Monitoring (Max.) |

<editor360-custom-block data-preprocessing="true" data-sanitizationtags="a"><h2><a></a><a></a>StF – Step 7</h2></editor360-custom-block>

See [Step 7](/v414/docs/step-7-determine-susceptibility-to-failure-stf-1).

The variables listed in the Parameter table in Step 2 above should be used to do the Susceptibility to Failure assessment. CR versus Design CR is assessed. API 581 contains theoretical CR based on variables in the Parameters table.

<editor360-custom-block data-preprocessing="true" data-sanitizationtags="a"><h2><a></a><a></a>Confidence – Step 10</h2></editor360-custom-block>

See [Step 10](/v414/docs/step-10-assess-the-confidence-1).

Follow the guidance below to determine answers for the Rich Amine Corrosion Confidence Assessment.

Rich Amine Corrosion Confidence Assessment Guidance:

| Key Questions | Guidance |
| --- | --- |
| Degradation mechanism can be properly controlled. | - "Yes": When all the IOWs in the table above are properly controlled and corrosion rate managed below 0.2 mm/y (8 mils/y). - "Intermediate": When operating conditions indicate a theoretical corrosion rate above 0.2 mm/y (8 mils/y); i.e., StF Medium. - "No": When one or more IOW limits are frequently exceeded or theoretical corrosion rate above 0.6 mm/y (24 mils/y); i.e., StF High. |
| Relevant process parameters are reliably monitored. | - "Yes": All relevant process variables known and actively monitored, including development of amine strength, heat stable amine salts and total solid content. - "Intermediate": Relevant process variables known but not actively monitored and/or exceedances not always acted on. - "No": No IOW available or no follow up on exceedances. |
| Reliable inspections were carried out. | - "Yes": 3 inspections above ‘usually effective’. - "Intermediate": 1 – 2 inspections above ‘usually effective’. - "No": No inspections or ineffective inspections. |

<editor360-custom-block data-preprocessing="true" data-sanitizationtags="a"><h2><a></a><a></a>Required Inspection Effectiveness – Step 11 &amp; Step 12</h2></editor360-custom-block>

See [Step 11](/v414/docs/step-11-review-the-results-nid-mii-is-inspection-effectiveness) and [Step 12](/v414/docs/step-12-assign-s-rbi-results-to-inspectioncorrosion-schedules-andor-update-monitoring-plan).

Use the Required Inspection Effectiveness rating, determined in [Step 11](/v414/docs/step-11-review-the-results-nid-mii-is-inspection-effectiveness), to determine the Inspection technique and coverage.

Guidance for General Thinning is provided in [Step 11](/v414/docs/step-11-review-the-results-nid-mii-is-inspection-effectiveness), while guidance for Localized Thinning is provided in [Lean Amine Corrosion](/v414/docs/lean-amine-corrosion).