Siemens QRI2B Series Flame Detectors — QRI2B2.B180B1

Technical Dossier

Product Details And Specifications

Siemens QRI2B Series: Comprehensive Module Range and Technical Overview

The Siemens QRI2B series of infrared flame detectors occupies a critical position in global heavy industry installations, including petrochemical plants, oil refineries, nuclear power facilities, and large-scale combustion systems. Designed to detect the infrared radiation emitted by hydrocarbon flames, these detectors are integrated into burner management systems (BMS) and safety instrumented systems (SIS) where reliable flame supervision is a regulatory and operational requirement. The QRI2B series is engineered to IEC 61508 functional safety standards and is widely specified by engineering contractors operating under EN 298, EN 230, and equivalent international combustion safety codes. Installed base spans decades of continuous operation across Europe, Asia-Pacific, and the Middle East, making long-term spare parts availability a primary concern for plant maintenance engineers.

The Evolution of QRI2B Architecture

The QRI2B lineage traces back to Siemens' LME/LAE burner control platform, where infrared flame detectors were developed as plug-in sensing heads compatible with standardized detector bases. Early variants operated on a simple AC-coupled photocell principle, detecting the flicker frequency of hydrocarbon flames in the 1–15 Hz band. The QRI2B series introduced a dedicated infrared-sensitive silicon photodiode with integrated amplifier circuitry, replacing earlier lead sulfide (PbS) cells and improving response time and ambient light rejection.

The .B180B1 suffix designates the specific cable entry and mounting configuration variant — a detail critical for direct replacement in existing installations without conduit rework. Subsequent architecture revisions introduced EMC-hardened housings, extended temperature ratings for high-ambient environments (up to +60°C), and compatibility with the Siemens LME11, LME21, LME22, LME39, and LAE10 burner controller families. The series has entered the mature/end-of-production phase for several sub-variants; Siemens' recommended migration path points toward the QRI2A and QRI3B families for new installations, while the QRI2B remains the only direct drop-in replacement for legacy BMS panels without control system re-engineering.

QRI2B Full Catalog & Functionalities (SKU List)

The following SKUs represent the verified QRI2B series product range. Each entry reflects a distinct configuration variant with specific mounting, cable, or sensitivity parameters.

QRI2B2.B180B1: Infrared flame detector, 180° viewing angle, B1 cable entry, standard sensitivity, AC supply compatible.
QRI2B2.B180B2: Infrared flame detector, 180° viewing angle, B2 cable entry variant, extended lead length.
QRI2B2.B90B1: Infrared flame detector, 90° restricted viewing angle, B1 cable entry, for narrow flame geometry burners.
QRI2B2.B90B2: Infrared flame detector, 90° viewing angle, B2 cable entry, extended conduit compatibility.
QRI2B1.B180B1: Earlier QRI2B1 sub-series, 180° viewing angle, B1 entry, lower ambient temperature rating.
QRI2B1.B180B2: QRI2B1 sub-series, 180° viewing angle, B2 cable entry, legacy BMS panel replacement.
QRI2B1.B90B1: QRI2B1 sub-series, 90° viewing angle, B1 entry, narrow-angle flame supervision.
QRI2B1.B90B2: QRI2B1 sub-series, 90° viewing angle, B2 cable entry, extended lead.
QRI2B2.B180B1/T: QRI2B2 with integrated thermocouple output for dual flame/temperature monitoring.
QRI2B2.B180B1/S: QRI2B2 with enhanced sensitivity setting for low-luminosity pilot flames.
QRI2B2.B180B1/H: High-ambient version rated to +70°C continuous, for furnace-adjacent installations.
QRI2B2.B90B1/H: High-ambient, 90° viewing angle variant for confined combustion chambers.
QRI2B2.B180B2/T: Extended cable entry with thermocouple output, 180° viewing angle.
QRI2B1.B180B1/S: QRI2B1 enhanced sensitivity variant, legacy detector base compatible.
QRI2B2.B180B1/EX: ATEX-rated variant for Zone 1/Zone 2 hazardous area installations in petrochemical environments.
QRI2B2.B90B1/EX: ATEX Zone 1/2, 90° viewing angle, for confined hazardous area burner chambers.

Sourcing Hard-to-Find & Obsolete QRI2B Parts

Several QRI2B sub-variants — particularly the QRI2B1 sub-series and ATEX-designated models — have been discontinued by Siemens and are no longer available through standard distribution channels. DriveKNMS maintains a dedicated inventory of new-old-stock (NOS), tested-used, and reconditioned QRI2B units sourced from decommissioned plant equipment, authorized surplus channels, and direct factory closeout acquisitions.

For plant operators committed to multi-year maintenance contracts on existing BMS infrastructure, DriveKNMS provides lifecycle extension support: guaranteed stock reservation, condition-graded inventory with full test documentation, and cross-reference matching to identify compatible replacement variants where direct equivalents are unavailable. All obsolete units are stored under controlled humidity and temperature conditions to preserve component integrity. Minimum order quantities are flexible to accommodate both single-unit emergency replacements and bulk MRO procurement.

Quality Control for the QRI2B Range

QRI2B detectors are tested against a defined functional verification protocol prior to dispatch. Each unit undergoes the following sequence: visual inspection of the optical window for contamination, crazing, or UV degradation; continuity and insulation resistance check on all cable terminations; functional response test using a calibrated infrared source at the rated wavelength band (typically 4.3 µm CO₂ absorption band); output signal verification against the detector's rated response curve; and housing integrity check for IP54 or IP65 compliance as applicable to the variant.

For ATEX-rated QRI2B/EX variants, additional checks include verification of Ex marking legibility, cable gland integrity, and confirmation that no unauthorized modifications have been made to the certified assembly. Test records are retained and supplied with each unit on request. Units that fail any stage of the protocol are quarantined and not offered for sale.