PLC Controlled Autoclave Pressure Tester, built for 150 bar cyclic testing.

1. Introduction

The Autoclave Pressure Tester is a highly sophisticated, portable, PLC-based cyclic pressure testing system designed to simulate extreme pressure conditions within a controlled chamber. Purpose-built for endurance, reliability, and leak-proof validation of small-to-medium-sized components, this system operates at pressure ranges up to 150 bar, and is structurally rated for 200 bar, conforming to international safety and testing norms such as ASME Section VIII Division 1, ISO 11120, and PD5500.

With its 13-liter SS304 pressure vessel, the system offers the ability to conduct batch testing of up to 12 components — significantly increasing throughput while maintaining absolute consistency. Whether it's evaluating the structural integrity of aerospace sensors, ensuring automotive hydraulic components can withstand fatigue loading, or testing the leak resistance of critical medical or defense components, this autoclave system offers unmatched control, repeatability, and safety.

2. Key functional capabilities

Advanced pressure profiling

Operators can configure sophisticated pressure cycles using the integrated PLC-HMI interface, with customizable parameters such as ramp-up time (5–15 minutes), hold duration (from 1 second to 24 hours), and number of cycles (up to and beyond 9 continuous cycles). This enables the simulation of real-world service conditions — especially critical for fatigue testing or accelerated life-cycle analysis.

Self-test validation routine

Before exposing UUTs (Units Under Test) to full test conditions, the chamber can undergo a stepwise pressure verification to detect any gasket leaks, micro-fractures, or clamp misalignments. This self-test is vital in high-stakes applications like defense, aerospace, and nuclear instrumentation.

Integrated safety logic

The system will not initiate pressurization unless all interlock conditions are met:

• Chamber lid is fully clamped and limit switch is triggered
• Working fluid level is above safe threshold
• Air supply is present and within required pressure range
• Filter elements are not clogged
• Control valves are in correct configuration
• Temperature sensors report within permissible limits

This ensures both operator and equipment safety, reducing the likelihood of human error during high-pressure operations.

Intelligent fill and drain control

A double-fill cycle (with pause) ensures full de-aeration of the autoclave using ISOPAR M or L. Automated air venting and level monitoring ensure complete coverage of the test specimens. Post-test, the system drains fluid back to the reservoir through return-line filtration for media reuse and environmental compliance.

Data logging & analysis

Pressure and temperature readings are sampled at 10 Hz frequency and plotted in real-time. Post-test analysis can be done using:

• Time-Pressure Graphs
• Cycle Completion Logs
• Custom CSV exports
• On-screen pressure trend visualizations

This is ideal for auditability, compliance documentation, and long-term trend studies.

3. System architecture

Autoclave chamber

Fabricated from SS304, the autoclave is pressure rated to 200 bar and houses up to 12 UUTs on a custom stainless-steel perforated tray. The internal mirror-polished surface (Ra ≤ 0.8 μm) facilitates cleaning and fluid drainage. The clamp-ring lid system includes a mechanical lockout and an electrical interlock switch, preventing pressure buildup if improperly sealed.

Pneumatic and hydraulic subsystems

• Drive Air: filtered to 40 microns, regulated at 7 bar
• Fill Pump: 5 LPM vane pump powered by a 2.2 kW motor
• Intensifier: converts pneumatic energy to achieve hydraulic pressures up to 150 bar
• Check & Relief Valves: prevent fluid backflow and contain overpressure events
• Dual Filtration: 10-micron return and suction filters with clog detection interlock
• Media Recovery: used ISOPAR fluid is routed through a fine-mesh return line filter to the reservoir

Instrumentation and automation

• PLC Control: real-time logic for pump, valve, intensifier, and sensor coordination
• Pressure & Temperature Sensors: WIKA certified, 0.25% FS precision
• Level & Limit Switches: ensure safe fluid levels and correct valve positions before each phase
• User Interface: Schneider Electric HMI with recipe programming, status logs, and alarm logs

4. Typical operation workflow

Pre-test checks

• Inspect gaskets, clamp system, and fittings for signs of wear
• Confirm air and power supply
• Fill hydraulic reservoir with ISOPAR M/L

Step-by-step operation

• Load 12 UUTs into tray and secure chamber lid
• Initiate Fill Cycle – automated air purging and dual-stage filling
• Run Self-Test – incremental pressure ramp to 150 bar to verify chamber sealing
• Execute Pressure Cycle Test – customizable cycles based on pressure/time logic
• Drain Cycle – pressurized ISOPAR fluid returns to tank through inline filter
• View or export TP Graph, event logs, and cycle summary

5. Applications in detail

Aerospace & Defense

• Life-cycle validation of solenoid valves, actuators, and pressure switches
• Leak-proof testing of sensor casings under simulated flight conditions

Automotive

• Pressure fatigue and burst testing of fuel injectors, braking components, and turbocharger seals

Medical Devices

• Certification of catheter integrity, implant enclosures, and pressure-sensitive delivery systems

Energy & Oil & Gas

• Testing hydrogen-compatible fittings, gas cylinder components, and safety valves

Industrial R&D

• Composite and polymer fatigue simulations
• Burst and yield testing for advanced materials

6. Advantages

• True batch capability: perform endurance tests on 12 units simultaneously
• Industry-leading safety: dual-stage relief, lid interlock, and filtered air logic
• Versatile and scalable: can be integrated into larger SCADA systems
• Mobility built-in: designed for deployment in both production and test labs
• User friendly: HMI provides clean visuals, error flags, and intuitive navigation
• Maintenance friendly: filters and valves are externally accessible; full service manual included

Conclusion

The PLC Controlled Autoclave Pressure Tester delivers unmatched control, repeatability, and safety for structural integrity, fatigue, and leak-resistance testing across aerospace, automotive, medical, energy, and industrial R&D applications. It can be custom-configured to meet unique testing requirements while remaining compliant with ASME Section VIII Division 1, ISO 11120, and PD5500 safety standards.