---
title: Ammonia Converter R-101 Temperature Excursion
doc_type: Incident Report
tags: [R-101, TAHH-101, FV-101, PSV-101, KM1R]
summary: An ammonia converter R-101 experienced a temperature excursion to 548 degC due to a feed purity upset, leading to TAHH-101 trip and depressurisation to flare.
---
**Incident Date:** 17 June 2022
**Equipment:** Ammonia Converter R-101, Bed #2
**Event:** Temperature excursion
**Excursion Temperature:** 548 degC
**Cause:** Feed purity upset
**Safety System Action:** TAHH-101 (set 530 C) tripped, cutting feed via FV-101 and depressurising to flare.
**Catalyst:** KM1R, inspected, no permanent damage found.

**Design Specifications**
*   **Design Pressure:** 180 barg
*   **Design Temperature:** 500 C
*   **Beds:** 3 axial-radial
*   **PSV-101 Setpoint:** 180 barg
*   **PSV-101 Capacity:** 12,400 kg/h to flare

**Operational Guidance**
*   **Pressure Ramp (Startup):** <= 5 bar/min
*   **Bed Inlet Hold (Startup):** 380-420 C
*   **Runaway Risk:** Above 530 C

**Action Taken:** Added feed-purity interlock.
**Status:** Closed
**Reported By:** K. Bose, HSE