How can pressurized systems be tested safely?

 

Pressurized systems are found in nearly all areas of industry – from hydraulics and pneumatics to gas and liquid systems in process and energy technology. Whether tanks, pipelines, valves, or complete assemblies: before they can be commissioned or delivered, they must be tested under realistic conditions.

However, testing these systems is far from trivial – on the contrary: it is one of the most safety-critical tasks in quality management. As soon as pressure is involved, the demands on technology, personnel, and test procedures increase significantly.

Typical risks of improper testing include:

• Pressure spikes and uncontrolled pressure curves that can damage or destroy components,

• Sudden system failure, for example due to material fatigue or defective seals,

• Hazards to personnel, e.g. from burst lines or escaping media,

• Incorrect test results if pressure values are not stable or precisely reproducible.

Such issues can have serious consequences, especially with safety-relevant components – for example in the aerospace, medical, or chemical industries. This makes it all the more important to have a test process that is not only accurate and standards-compliant, but also always controllable and documentable.

The objective is therefore:
A safe, repeatable, and standards-compliant test in which the pressure is precisely built up, maintained, and controlled – without fluctuations and without risk. Only in this way can both technical requirements and legal regulations be reliably met.

A modern solution to this challenge: electronically controlled pressure regulators with freely definable pressure profiles, such as those realized with the PACE system from Druck.

 

→ Challenges in pressure testing

Testing pressurized systems is not a standardized one-size-fits-all process – it varies depending on application, medium, safety requirements, and legal regulations. Different scenarios each require specifically tailored testing strategies.

Some of the most common test types include:

• Leak test: Detection of leaks, usually at low pressure.

• Tightness test: Verifying whether a system can maintain pressure over a defined period of time.

• Burst pressure test: Determining the maximum pressure resistance up to system failure.

In practice, users are faced with a number of typical challenges:

 

Overview of key challenges

A particular challenge lies in meeting all these requirements simultaneously: while accuracy must increase, economic pressure is also rising – test processes must become faster, more affordable, and still safer.

Only precisely controlled and automatable test sequences can meet these challenges. This is exactly where modern electronic pressure controllers such as the PACE system come into play – with the ability to define test profiles precisely and execute them in compliance with standards.

 

→ Solution approach: Automated pressure control with the PACE system

To master the challenges of pressure testing outlined above, the use of precise, automated pressure control systems is recommended. A proven solution is the PACE system from Druck (a Baker Hughes company) – consisting of the PACE5000/6000 pressure controller and high-precision interchangeable pressure modules.

Introduction to the PACE pressure controller

The PACE controller is a digital pressure controller that combines precise pressure control, user-friendly operation, and flexible system integration. Control is via a large color display or remotely via PC or PLC. Depending on the version (PACE5000 or PACE6000), one to three pressure control modules can be operated simultaneously – ideal for single test benches or complex multi-channel systems.

 

Advantages over manual or semi-automatic methods

Manual pressure testing with hand pumps, pressure relief valves or analog displays is prone to error and lacks precision. Semi-automated test benches with pneumatic controllers offer only limited flexibility. The PACE system sets new standards:

→ Function: Freely Definable Pressure Profiles

A key advantage of the PACE system lies in the ability to create freely definable pressure profiles – tailored precisely to the respective test procedure. The controller enables automatic execution of complex pressure sequences without manual intervention and with the highest repeatability.

Supported Pressure Sequences

The system supports both linear and nonlinear pressure profiles, including:

• Ramp: Continuous increase or decrease of pressure over a defined period

• Step: Sudden change of pressure to a target value

• Hold: Maintaining a certain pressure level over a defined duration

• Cycle: Repeated sequence of rise, hold, and drop – ideal for long-term stress testing

These profiles can be executed individually or combined into a complete process plan.

Example Test Profiles in Practice

Advantages of Profile Control with PACE

• Repeatability: Consistent test conditions for every unit – independent of the operator

• Speed: Automated sequences save time compared to manual procedures

• Flexibility: Profiles can be freely configured via user interface or remote control

• Safety: Gentle pressure ramping reduces mechanical stress, protects components and personnel

With these features, the PACE system is not only a precise pressure controller, but also a powerful tool for the standardization and automation of test processes – especially in quality assurance, product development, and manufacturing.

 

→ Safety Aspects in Application

In pressure testing, the safety of people, equipment, and materials always takes top priority. Incorrect test conditions – such as excessively rapid pressure rise or missing limit monitoring – can not only damage components, but also cause serious accidents. The PACE pressure control system plays a key role in minimizing these risks.

Gentle Ramp-Up and Controlled Venting

A sudden pressure rise poses a significant risk – especially with sensitive components or when testing gases. The PACE controller enables gentle, precisely controlled pressure ramp-up, with freely definable ramp rates. This ensures that stress on the test specimen is minimized and false test results are avoided.

Equally important is controlled venting after the test. The PACE controller can reduce pressure gradually instead of releasing it abruptly – protecting both the test object and connected piping, valves, and measuring devices.

Limit Monitoring and Alarm Functions

Another key safety feature is the integrated limit monitoring:

• The user can define upper and lower pressure limits.

• If a limit is exceeded, the controller intervenes automatically – by shutting off, reducing pressure, or issuing an alarm.

• Warning messages on the display or via digital interfaces immediately alert the operator to critical conditions.

These functions not only increase safety, but also support the compliance with regulatory requirements, such as the Pressure Equipment Directive or ISO 12100 for risk minimization.

Protection of Sensitive Test Specimens through Precise Control

In many cases, sensitive products such as microtubing, plastic housings, sensors or electronic assemblies need to be tested. These are susceptible to pressure fluctuations or uneven loading.

Thanks to its very fine control characteristics (up to 0.005% FS), the PACE system reliably protects such specimens. It minimizes mechanical stress by:

• precisely adjustable ramp profiles,

• shock-free switching between pressure levels,

• even control even at very low pressures or volumes.

 

→ Use Case: Safe Testing of a Hydraulic Power Unit

Initial Situation: Testing for Operating Pressure with Safety Margin

A medium-sized machine manufacturer produces hydraulic power units for use in automated production systems. Each unit must undergo a pressure test before delivery, during which the operating pressure resistance plus a 25% safety margin is verified. The test is performed with hydraulic oil and a target pressure of 275 bar (operating pressure: 220 bar).

Previous tests were performed manually using a pressure reducer, analog pressure gauge, and mechanical safety valve – a procedure that:

• depended heavily on the operator's experience,

• did not deliver documented results,

• led to irregular pressure curves and unnecessary stress on materials,

• took several minutes per unit to complete.

Implementation with PACE Controller and PACE Pressure Module

To optimize the test process, the test bench was equipped with a PACE5000 controller and a matching PM6000 pressure module (range up to 300 bar). Using the intuitive user interface, an automated test procedure was configured:

1. Slow pressure ramp-up (Ramp) to 275 bar within 60 seconds

2. Hold pressure for 90 seconds with tolerance ±0.1 bar

3. Controlled pressure reduction to 0 bar over another 30 seconds

4. Automatic test data logging via Ethernet interface

In parallel, a limit monitoring was activated: If pressure falls outside the permitted range during the test, the procedure is aborted immediately and an error message is displayed.

Result: Time Savings, Reliable Documentation, Repeatable Procedures

Switching to the PACE system led to measurable improvements in the test process:

Thanks to precise control, the hydraulic system is tested for operational strength gently and reliably. Moreover, the new process meets the internal quality assurance and ISO 9001 requirements in terms of traceability and documentation.

Using the PACE controller in the pressure testing of hydraulic power units clearly demonstrates how safety, efficiency, and quality can be improved through modern test automation – while reducing test time and personnel requirements.

 

→ Integration into Existing Test Environments

A major advantage of the PACE pressure control system lies in its high integrability. Whether it's an existing test bench, a semi-automated test station, or a fully automated PLC-controlled system – the system can be flexibly and future-proofly integrated into almost any environment.

Wide Interface Support

The PACE5000/6000 comes standard with numerous industry-compatible interfaces that enable easy connection to control systems, computers, or data acquisition systems:

This allows the PACE system to be integrated both into traditional laboratory environments and into modern, networked industrial systems.

Integration into Test Benches and PLC-Controlled Systems

The PACE controller can be operated either stand-alone with local control or fully remote-controlled. In PLC-based systems, the controller (e.g. Siemens S7, Beckhoff, Wago) executes the test sequence while the PACE controller performs real-time pressure regulation.

Typical integration examples include:

• Test benches in series production with HMI and barcode scanning

• Test automation systems with safety interlocks and automatic test object changeover

• Development labs with varying test parameters

• OEM test systems with modular architecture

Optional Software: 4Sight2 for Documentation & Automation

For users who require complete traceability and test management, the optional software 4Sight2:

• Creation, management, and execution of test plans

• Automatic recording and archiving of pressure sequences

• Configurable test reports (e.g. PDF, XML, CSV)

• Integration into networks and databases

• User management, audit trail, calibration reminders

The software is especially useful for ISO 9001-certified companies, laboratories with regular audits, or production facilities with high documentation requirements.

Thanks to its wide range of communication interfaces and optional software solutions, the PACE system can be seamlessly integrated into existing test and automation environments – from simple workstations to networked smart factories.

 

→ In Summary

The safe testing of pressurized systems is a core element of modern quality assurance – whether in serial production, development, or calibration labs. And it involves far more than just reaching a target pressure: The entire pressure sequence must be precisely controlled, repeatable, and documented – in compliance with the highest safety and regulatory standards.

Manual or semi-automated testing methods quickly reach their limits. Only with precise, automated control technology can pressure tests be carried out efficiently, safely, and in accordance with standards.

The PACE pressure controller from Druck delivers exactly that:

• Freely definable pressure profiles for all common test methods (e.g. ramp, step, hold, cycle)

• Highest control accuracy with gentle pressure ramp-up and safe venting

• Easy integration into existing test benches or PLC-controlled systems

• Reliable limit monitoring to protect personnel and test items

• Complete documentation via interfaces or the optional 4Sight2 software

Whether in quality assurance, a development lab, incoming goods inspection or end-of-line production:
The PACE controller is the reliable solution for anyone who doesn't want to leave pressure testing to chance.