The pressure vessel industry demands the highest levels of structural integrity, dimensional stability, and compliance with international standards such as ASME Section VIII, PD 5500, and EN 13445. One of the most critical steps in meeting these criteria is post-weld stress relief heat treatment. This is where industrial stress relief furnaces for pressure vessel manufacturers become indispensable.
Maan Global Industries, a leading stress relief furnace manufacturing company, supplies high-capacity, PLC-controlled thermal systems specifically designed for the heat treatment of pressure vessel components. These systems ensure uniform temperature distribution, controlled ramp rates, and repeatable thermal cycles—essential for preventing distortion, cracking, and premature failure of pressure-bearing structures.
Why Is Stress Relief Heat Treatment Important for Pressure Vessels?
Table of Contents
Welding and forming processes used in pressure vessel fabrication introduce residual stresses into the material. These internal stresses, if left untreated, can lead to:
-
Warping or deformation during service
-
Cracking near welds under pressure or thermal cycling
-
Compromised fatigue resistance
-
Non-compliance with ASME and customer specifications
To avoid these issues, stress relief is conducted by heating the vessel to a sub-critical temperature (typically between 550°C and 700°C for carbon steels), soaking it for a calculated period based on material thickness, and cooling it under controlled conditions.
Post Weld Heat Treatment Furnace Manufacturer
Benefits of Stress Relief for Pressure Vessels
-
Reduces residual tensile stress caused by welding or rolling
-
Prevents brittle fracture in low-temperature applications
-
Improves dimensional stability during future machining or operation
-
Increases fatigue life in cyclic loading environments
-
Ensures code compliance for vessel registration and certification
A high-performance stress relief furnace for pressure vessel manufacturers ensures uniform heating over large weldments and enables full documentation of time-temperature cycles for inspection audits.
Types of Stress Relief Furnaces Used by Pressure Vessel Manufacturers
As a trusted stress relief furnace supplier, Maan Global provides furnace systems based on component size, material grade, and heat treatment volume.
| Furnace Type | Description | Suitable For |
|---|---|---|
| Bogie Hearth Furnace | Heavy-duty movable car (bogie) with walk-in chamber, side or top loading | Complete vessels, large shells, jackets |
| Pit Type Furnace | Vertical loading system, insulated pit with top opening | Cylindrical components, nozzles, shafts |
| Box / Chamber Furnace | Horizontal static loading, front access, often trolley-assisted | Dish ends, flanges, small assembled vessels |
| Gas Fired Furnace | High-capacity systems using LPG or PNG with modulating burners | Fuel cost-effective setups for large components |
| Electric Furnace | Precise PID-controlled resistance heated system | Clean indoor operation, tight temp accuracy |
Technical Table – Typical Heat Treatment Parameters
| Parameter | Standard Range | Notes |
|---|---|---|
| Preheat Temperature | 100–200°C | Optional, for thick weldments |
| Stress Relief Temperature | 550°C – 700°C | Depends on material (e.g., SA 516, SA 387) |
| Heating Rate | 30–100°C/hr | As per ASME code guidelines |
| Soaking Time | 1 hour per 25mm thickness (min 30 min) | Uniform hold across the part |
| Cooling Rate | 100°C/hr max until 300°C, then air cool | Controlled cooling prevents distortion |
| Atmosphere | Air (inert optional) | Nitrogen or argon used in sensitive cases |
| Control System | PID or PLC + SCADA | Data logging and remote monitoring available |
| Thermocouple Control Zones | 3–8 zones | Depends on furnace size and vessel geometry |
Industry Standards and Compliance
Maan Global’s stress relief furnaces comply with international codes and customer quality standards:
| Standard | Furnace Compliance Method |
|---|---|
| ASME Section VIII | Certified time-temp cycle, thermocouple placement documentation |
| ISO 9001:2015 | Process and calibration control |
| AMS 2750 (Aerospace) | Multiple control zones, uniformity testing, SCADA traceability |
| EN 13445 | Furnace qualification, thermal profiles for European certification |
Our systems include multi-point thermocouple input, digital chart recorders, and auto-shutdown features to ensure zero risk of overheat or cycle failure.
Tempering Furnace Manufacturer
Real-World Use Cases – Pressure Vessel Fabrication Facilities
1. Horizontal LPG Bullet Tanks
-
Location: Hyderabad, India
-
Furnace Type: Gas fired bogie hearth, 4m wide × 4m high × 12m deep
-
Load: 20-ton fabricated tanks
-
Result: < ±10°C temp deviation, ASME audit passed
2. Reactors and Heat Exchangers
-
Location: Jubail, Saudi Arabia
-
Furnace Type: Pit type electric furnace, 750°C max temp
-
Load: 6-ton forged shells with welded nozzles
-
Result: Controlled stress relief without oxidation
3. Pressure Filters & Autoclaves
-
Location: Nairobi, Kenya
-
Furnace Type: Box furnace with front trolley loading
-
Output: 2-3 units per batch, SCADA integrated
-
Result: Batch traceability, smooth ISO audit
Furnace Selection Guide – Based on Vessel Geometry
| Component Type | Typical Dimensions | Recommended Furnace Type |
|---|---|---|
| Horizontal Shells | Dia: 1–3 m, Length: 4–12 m | Gas-fired bogie hearth furnace |
| Vertical Columns | Dia: 0.8–2.5 m, H: 3–7 m | Pit type stress relief furnace |
| Dish Ends | Dia: 0.6–3 m, Thickness: 10–75 mm | Electric box furnace |
| Nozzles, Flanges | Dia: 100–800 mm | Batch type electric furnace |
| Jacketed Vessels | Complex geometries | Bell or bogie furnace with airflow circulation |
Construction & System Design Highlights
Every Maan Global stress relief furnace for pressure vessel manufacturing includes:
-
Double-wall insulated structure (ceramic wool or refractory)
-
Mild steel or stainless interior with expansion clearance
-
High-efficiency blowers for air movement & temperature uniformity
-
Integrated burner management system (for gas units)
-
Remote access via Ethernet/SCADA system (optional)
Optional Add-ons
-
Trolley system or hydraulic lifters for heavy-duty part loading
-
Automatic data logging and digital audit trail
-
Pressure port monitoring for vessel integrity post-treatment
-
Atmosphere gas system (argon, nitrogen, mixed gases)
-
Temperature uniformity survey kit for qualification
Supply and Installation Footprint
Maan Global Industries supplies turnkey furnace systems to:
-
India: Pune, Hyderabad, Chennai, Delhi NCR, Ahmedabad
-
Saudi Arabia: Dammam, Jubail, Riyadh
-
UAE: Dubai, Sharjah, Abu Dhabi
-
Africa: Kenya, Ghana, South Africa, Tanzania
We deliver with complete layout drawings, foundation specs, commissioning, and training.
Contact the Expert in Stress Relief Furnaces for Pressure Vessel Manufacturers
Maan Global Industries is your trusted partner for high-performance stress relief furnaces for pressure vessel manufacturers. With decades of furnace engineering experience, global installations, and compliance to ASME and ISO codes, we provide not just a system—but a solution that ensures reliability, documentation, and process stability.
Email: mail@maanglobalindustries.com
Call/WhatsApp: +91-8882490101
