Controlled Heat Treatment for Weld Integrity & Stress Relief

PWHT & Preheating Services

Post weld heat treatment and controlled preheating services for piping, pressure vessels, tanks, and structural fabrication systems.

Technicians performing localized PWHT on industrial piping weld using electric resistance heating pads
Electric resistance, induction, gas-fired, furnace heating
Piping, vessels, tanks, structural fabrication
PWHT, preheating, normalizing, annealing, tempering
Offshore and onshore operations

PWHT & Preheating Services for Welding Integrity and Stress Relief

Fairtex delivers Post Weld Heat Treatment (PWHT) and controlled preheating services for piping systems, pressure vessels, storage tanks, structural steel, and fabrication assemblies across offshore and industrial environments. The service is designed to improve weld microstructure, reduce residual stresses, and support compliance with applicable welding and fabrication codes.

Our heat treatment capabilities include localized electric resistance heating, induction heating, gas-fired systems, and temporary or permanent furnace heat treatment solutions. Services are executed by experienced heat treatment specialists using calibrated monitoring systems and controlled heating cycles to ensure process consistency and metallurgical integrity.

Typical applications: process piping welds, pressure vessels, refinery systems, offshore platforms, storage tanks, structural fabrication, bullet tanks, bridge structures, petrochemical facilities

What this service covers

Localized PWHT for Piping & Vessel Welds

Fairtex performs localized PWHT on butt welds, closing seams, and structural welds using electric resistance heating pads and induction coil systems. Controlled heating and cooling cycles help minimize residual stress and improve weld performance in pressure-containing systems.

Preheating for Welding Operations

Preheating services are provided prior to welding to reduce thermal shock, prevent hydrogen cracking, and improve weld quality. Heating methods are selected based on material type, wall thickness, and welding procedure requirements.

Furnace Heat Treatment & Normalizing

Temporary and permanent furnace heat treatment services are available for normalizing, annealing, tempering, and stress relieving applications. Systems can be configured using gas firing, oil firing, induction heating, or electric resistance methods depending on project requirements.

Tank & Large Vessel Heat Treatment

Fairtex performs internal high-velocity gas firing for spherical tanks, bullet tanks, and large storage vessels where localized heating is not practical. This supports uniform thermal treatment for large fabricated structures and pressure-retaining systems.

Code Compliance & Temperature Monitoring

All PWHT activities are executed in accordance with applicable welding codes and client specifications. Temperature control and recording systems are used throughout the heating cycle to maintain compliance and provide traceable documentation.

Key Takeaways

  • Localized and furnace-based PWHT solutions for industrial fabrication
  • Electric resistance, induction, gas-fired, and oil-fired heating methods
  • Supports weld integrity, stress relief, and metallurgical stability
  • Applicable to piping, vessels, tanks, and offshore structures
Equipment

Instruments and systems used for this service.

Localized Heat Treatment Equipment
Electric Resistance Heating Pads
Used for controlled PWHT and preheating of piping welds and vessel seams.
Induction Heat Treatment Equipment
Induction Heating System
Provides rapid and uniform heating for weld joints and fabrication assemblies.
Furnace Heating System
Gas-Fired Heat Treatment Furnace
Used for large-scale normalizing, annealing, and stress relieving applications.
Process Control Instrumentation
Temperature Recording & Monitoring Unit
Monitors and records heat treatment cycles for QA/QC traceability and compliance.
Standards

Codes and standards this service conforms to.

Requirements for heat treatment in pressure vessel fabrication and welding
ASME Section VIII
Rules for Construction of Pressure Vessels
Welding and fabrication code requirements for structural and piping systems
ASME B31.3
Process Piping
Qualification and certification requirements for non-destructive testing personnel
ISO 9712
Non-destructive testing — Qualification and certification of personnel
Deliverables

What you receive.

PWHT Temperature Charts

Recorded heating and cooling cycle data for compliance verification.

Heat Treatment Compliance Report

Documentation confirming process execution in accordance with specified procedures.

Thermocouple Placement Records

Traceable documentation of monitoring locations and temperature measurement points.

QA/QC Inspection Documentation

Inspection records and verification reports supporting fabrication quality assurance.

Have a Scope?

Let’s get it scoped and quoted.

Our team will review your scope and return a proposal.

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