The famous contactless measurement proximity sensor TQ402 111-042-000-013 has been replaced by the newly upgraded TQ902 111-902-000-011 sensor. TQ902 is functionally identical and backward-compatible with the existing TQ4x2 proximity measurement chain, delivering overall improved performance versus the legacy TQ402.

TQ902 brings improved mechanical performance. It supports 6-bar differential pressure (compared with 1 bar for TQ402), with 225 N tensile resistance for cables and connectors. The integral probe cable withstands minimum 225 N tensile pull load, higher than TQ402’s 200 N rating.

Additionally, TQ902 conforms to API 670 5th edition and is suitable for use in potentially explosive hazardous areas.

Quick Answer

The legacy TQ402-series proximity probe has been superseded by TQ902. It is plug-and-play backward-compatible, offers higher mechanical strength, higher differential pressure rating, meets API 670 5th standard and supports hazardous-area installation, serving as the direct drop-in replacement for TQ402 111-042-000-013.

Key Takeaways

1. Direct replacement: TQ902 111-902-000-011 replaces TQ402 111-042-000-013, full backward compatibility with existing TQ402 measurement system, no modification required for most existing installations.

2. Mechanical upgrade: Differential pressure resistance upgraded from 1 bar to 6 bar; cable tensile load increased from 200 N to 225 N.

3. Industry compliance: Complies with API 670 5th edition, certified for potentially explosive sites.

4. Drop-in migration: Existing TQ402 wiring, mounting brackets and extension cables can be reused for TQ902 retrofit projects.

Parameter Comparison Table

Practical Application Case

Project background: A petrochemical plant in Southeast Asia operates centrifugal compressors for hydrocarbon processing. The site originally deployed TQ402 proximity probes for shaft vibration and shaft position monitoring.

• Pain points:Site process fluctuation generates higher differential pressure; several old TQ402 probes suffered cable stress damage under heavy vibration; existing hardware needed to meet API 670 5th revision audit requirements.
• Solution:Completed retrofit with TQ902 111902000011. Reused original mounting hardware, extension cables and monitoring system without hardware changes to control project cost.
• Field result:
  1. 6 bar differential pressure rating adapts to fluctuating process conditions;
  2. 225 N tensile resistance effectively reduces cable break‑down risk under long‑term unit vibration;
  3. Meets API 670 5th edition audit requirements for hazardous compressor area.

FAQ

Q1: Can I directly swap TQ902 in place of old TQ402 without changing other system parts?

A: Yes. TQ902 is backward-compatible for the TQ402 measurement chain. Existing mounting fixtures, extension cables and monitoring unit can be kept for direct replacement. No software adjustment is needed for basic operation.

Q2: What is the core difference between TQ902 and TQ402 besides mechanical parameters?

A: The core measuring function remains consistent. Main upgrades focus on mechanical robustness and standard compliance: higher differential pressure resistance, higher cable tensile strength, and compliance with API 670 5th edition for explosive-risk working conditions.

Q3: Is TQ402 still available for purchase?

A: TQ402 111-042-000-013 has been superseded. TQ902 111-902-000-011 is the recommended new part number. Limited engineering surplus stock of TQ402 may occasionally exist, yet TQ902 is preferred for new projects and maintenance orders.

Q4: Does TQ902 require special certification documents for explosive-area installation?

A: TQ902 complies with API 670 5th edition for potentially explosive sites. Relevant compliance documents can be provided upon customer request for project submission and site audit.

Q5: Will measurement reading drift occur after replacing TQ402 with TQ902?

A: Functionally identical. In normal conditions readings will be consistent. On-site gap calibration is still suggested after physical replacement to optimize measuring accuracy for rotating machinery.