Closed-loop high-pressure test system
Highly automated closed-loop test systems for natural gas up to 66 bara – including gas exchange, compression and recovery. Realised for pigsar and Qbig among others.
What the system delivers
In the closed circuit the test gas is compressed, temperature-controlled and passed through the measuring section. As no gas is vented, operating costs and emissions drop significantly – and the operating conditions of real high-pressure networks can be reproduced exactly.
The gas exchange process from filling through pressure testing to recovery is fully automated and safety-related. All pressure-bearing components are supplied with works test certificates and Pressure Equipment Directive documentation.
Operators are national metrology institutes, calibration service providers and network operators who calibrate high-pressure meters under real network conditions.
Real network conditions without venting gas
No venting of test gas – low operating costs and significantly lower emissions.
Calibration at the real operating pressures of high-pressure transmission networks.
Measurement uncertainty down to ≤ 0.193 %, secured by several reference lines.
Filling, testing, emptying and recovery as a monitored process sequence.
Design to the Pressure Equipment Directive, gas detection and shutdown concept.
Realised for national institutes and calibration service providers such as pigsar and Qbig.
Technical specification
Configuration and expansion
System design for H₂ and natural gas/H₂ mixtures.
Extension of the circuit to further operating pressure ranges.
Additional line for interlaboratory comparisons and reference calibrations.
Process data logging and remote diagnostics by inotech service.
Do you have specific technical requirements?
Send us your specification – meter types, flow ranges, number of test positions and the required degree of automation.
High-pressure gas meter test system using the closed-loop method
Calibrating under operating pressure, just as the meter will later measure in the network: this is what inotech develops the high-pressure gas meter test system for. The test gas circulates in a closed loop, driven by a special blower design in which the radial blower and drive motor are located inside. A matched cooling system removes the heat introduced so that the gas temperature remains constant. The device under test is integrated into a line with reference meters and compared directly with them. The deviation between the two is the result of the calibration.
Why closed loop? The loop makes it possible to apply high pressure, temperature and flow rate to the gas meter in a stable manner close to operating conditions. Because the gas is not vented after every test point, the consumption of natural gas or compressed air remains economical. Compressed air and inert gases are suitable for testing in the factory, while natural gas reproduces the conditions in the network most directly.
The measurement uncertainty of a high-pressure gas meter test system is at most 0.193 %; the design is recognised by the Physikalisch-Technische Bundesanstalt (PTB). For test centres and manufacturers, this recognition is the basis for verifying results reliably. For domestic, commercial and industrial gas meters at low pressure, we offer the matching gas meter test system with ambient air as the test medium.
Short stabilisation times for more calibrated meters per day
Measurement only begins once pressure, temperature and flow rate are stable. At high pressures and large volume flows, it is precisely this phase that determines how long a calibration takes. Our high-pressure gas meter test system achieves extremely short stabilisation times for all three variables.
The effect adds up over the day. Less waiting time per test point means more calibrated meters per shift, without you having to procure a second system. A high-pressure gas meter test system with short stabilisation times thus reduces the cost per calibrated meter.
The control system also contributes: the sequence is fully automatic, from approaching the test points to evaluation in our Meter Calibration Software. Your staff monitor the run instead of readjusting valves by hand. In this way, the system enables calibration of every high-pressure gas meter under reproducible conditions, test run after test run. If you operate several test centres, our InoCloud bundles the calibration data centrally and monitors the condition of each test centre through comparison measurements with golden meters.
Configuring the high-pressure gas meter test system around your reference meters
Almost any configuration of reference meters can be integrated into the test line. The high-pressure gas meter test system is thus based on the reference meters your laboratory already uses. For laboratories with their own standards that are already traceable, this saves investment in new reference technology and shortens familiarisation, because your staff continue working with familiar references. We also determine the length of the test line according to your meter types.
For the volume flow, the number of blowers counts, each with its own heat exchanger and connection to a chilled water system. How many of them your system needs depends on the largest flow rate you want to test. As a test medium, the high-pressure gas meter test system works with compressed air, inert gases or natural gas.
Are you already planning a later expansion? Thanks to the modular design, the test line and blower capacity can also be adapted retrospectively. New reference meters, a longer test line or an additional blower thus make your system ready for larger meters.
Scope of supply from engineering to turnkey system
You decide how much we supply. The offer for a high-pressure gas meter test system ranges from engineering and core components to a complete turnkey system, which we implement together with partners. With existing high-pressure test benches in particular, it can make sense to commission only engineering and core components. In every case, the project begins with engineering, in which we define pressure stages, flow range and test medium.
If the engineering and core components of your high-pressure gas meter test system come from us, we guarantee certification of the promised measurement uncertainties by the PTB. The PTB is a member of the International Organization of Legal Metrology (OIML). This commitment gives you planning certainty for the later certification of your test line as early as the award of the contract.
A dedicated team at our company works exclusively on high-pressure calibration systems for gas meters. Your questions are thus handled by the same experts from the first design to commissioning. This saves rounds of coordination. Our support services then cover maintenance, software updates and spare parts over the entire service life. We also modernise an existing high-pressure gas meter test system, for example with a new PC generation and current software. Because we cover water and heat as well as gas, laboratories with a mixed test spectrum receive every meter test system from a single source.
The most extensive reference list for closed-loop high-pressure test systems
We have been building closed-loop high-pressure test systems for more than ten years. No supplier has a more extensive reference list for closed-loop high-pressure test systems than we do. The first bidirectional high-pressure test system, which calibrates in both flow directions, is based on our concept and our core components. The world’s shortest stabilisation times for closed-loop high-pressure systems also go back to our development. For an energy supplier, we have also implemented the world’s fastest rotary gas meter test system.
If you would like to build a new high-pressure gas meter test system or expand an existing high-pressure test bench, describe the test medium, pressure stages and flow range to us. On this basis, our sales team will prepare a free quotation, coordinated with the high-pressure team. For projects outside Germany, we work with exclusive partners and representatives in Europe, Asia, the Americas and Oceania.