Among our pressure test benches you can find many types. Therefore, it is easy to get bogged down in the choice. To avoid this, and to save you time, we have prepared this comparative material to help you choose the ideal pressure bench.
The most suitable water pressure testing machine can be selected for the following areas:
- fire extinguisher pressure testing machine
- Low-pressure gas cylinder hydrostatic tester
- Inspection of high-pressure industrial gas cylinders
The article also contains information on the use of water pressure testing machines and a description of their usage cycles.
Choosing the right pressure testing machine isn't easy
We generally test gas cylinders at one and a half times their normal operating pressure. We test a 200 bar gas cylinder with 300 bar. We carry out the pressure test with water.
Unlike gases, liquids can only be compressed to a very small extent. Therefore, even if a gas cylinder fails a pressure test, it will not explode, but at most the environment around the machine will get wet.
Our machines help to carry out the hydrostatic testing process, to various degrees of automation. The table above contains all the main data for selection: pressure data, gas cylinder sizes, productivity and capacity data as well.
Fire extinguisher bottles check
Fire extinguishers are generally pressurised to 10-15 bar. Therefore, a 50 bar pressure test is sufficient for the tanks used here. We generally recommend mobile solutions, so the work can also be carried out on site.
Our mobile product range:
- HT35
- N7/1FH-E
- N7/1FH-E AA – the model already includes an air blower for drying the inside of fire hoses
Pressure testing of CO2 fire extinguishers
With carbon dioxide extinguishers, we encounter pressurised gas cylinders. Carbon dioxide can be found in both liquid and gaseous states within the cylinder.
The gaseous and liquid states together create a stable pressure, which changes due to temperature. The cylinders of carbon dioxide extinguishing appliances generally have a test pressure of 250 bar, and occasionally 212 bar.
Large quantities of low-pressure industrial gas cylinders
For testing low-pressure industrial cylinders, we recommend the FIT50-LOW machine, which carries out the testing process fully automatically.
The machine has already been optimised for handling welded flanges. The clamping mechanism has been developed for quick and secure connection.
The high-pressure members of the FIT50 series can also be used for low-volume sampling of low-pressure cylinders, but the welded flange and large diameter always require unique manual rework. Therefore, it is not recommended for large volumes of low-pressure cylinders.
High-pressure series for high workload: FIT series
The high-pressure FIT series is produced in 4 main versions.
Pressure test bench FIT series versions
- FIT50: Semi-automatic press. Allows testing of 6 bottles simultaneously in each cycle.
- FIT50-DUO: Semi-automatic pressure pad. Allows for simultaneous testing of 6 + 6 bottles in each cycle.
- FIT-6-EVO: Automated pressure test bench. Allows simultaneous testing of 6 bottles in each cycle.
- FIT-6 DUO-EVO: Automated pressure test bench. Enables simultaneous testing of 6 + 6 bottles in each cycle.
Operating principles for pressure testing gas cylinders
FIT50
The machine allows for refilling gas cylinders with water, performing the pressure test, and then emptying the cylinders. The water used for the pressure test can be reused, or discharged according to the customer's operating instructions.
The operator manually changes the filling, pressure testing, and emptying heads on the bottles before each step.
- Cycle time Filling, 300-bar pressure testing, and emptying 6 x 50-litre cylinders takes approximately 12-15 minutes. Accordingly, approximately 24 gas cylinders can be tested per hour.
- Drying The bottles must be dried after the pressure test. Recommended dryers: CIL model or DRY-VAP model.
FIT50-DUO
The machine operates similarly to the FIT50 principle. The main difference is that the FIT50-DUO is equipped with a two-gas cylinder switching unit.
As a result, the operator can work alternately on one and the other filling unit. The two bottle-filling operations increase productivity and allow for the integration of the drying system into the pressure test bench.
- Cycle time With the FIT50-DUO machine, approximately 42 x 50-litre gas cylinders can be tested per hour with 2 operators at 300 bar.
- Drying The bottles must be dried after the pressure test. Recommended dryers: CIL model or DRY-VAP model.
FIT-6-EVO
The machine allows for refilling gas cylinders with water, performing the pressure test, and then emptying the cylinders. The water used for the pressure test can be reused, or discharged according to the customer's operating instructions.
The operator must manually connect the filling, testing and emptying head to the gas cylinders. The filling and testing head is a specially designed connector, which allows the operator to connect the cylinder in seconds, without screwing. This increases productivity and reduces operator time.
- Cycle time Filling, pressure testing to 300 bar, and emptying 6 x 50-litre cylinders takes approximately 10 minutes. Correspondingly, about 30 gas cylinders can be inspected per hour.
- Drying The bottles must be dried after the pressure test. Recommended dryers: CIL model or DRY-VAP model.
FIT-6DUO-EVO
The operating principle of the machine is the same as the FIT-6-EVO model. The main difference is that the FIT-6DUO-EVO is equipped with two gas cylinder reversing units.
As a result, the operator can work alternately on one and the other filling unit. The two bottle-filling operations increase productivity and allow for the integration of the drying system into the pressure test bench.
- Cycle time With the FIT-6DUO-EVO machine and 2 operators, approximately 54 50-litre gas cylinders can be tested per hour at 300 bar.
- Drying The bottles must be dried after the pressure test. Recommended dryers: CIL model or DRY-VAP model.
Drying systems for the FIT series
The following gas cylinder dryers are available: CIL6 / 10 or DRY-VAP.
CIL6 / 10
The operating principle is as follows: hot air is blown into the gas cylinder. The CIL dryer can be used in two ways. It can be used as a separate unit next to the pressure test bench, or it can be integrated into the FIT series pressure test bench.
If the machine is used next to the test bench, the operator must manually move the gas cylinders being tested from the pressure test bench to the gas cylinder dryer. If the dryer is integrated into the pressure test bench, the test bench will immediately dry in a vertical position after the pressure test.
Drying 6 x 50-litre gas cylinders takes approximately 18 minutes. If the CIL machine is integrated into the FIT pressure testing bench, then the machine cannot be used for pressure testing during the drying cycle. This reduces the productivity of the FIT machine.
If the CIL dryer is installed next to the FIT, then the CIL drying time will not affect the FIT machine's performance. The installation of two CIL gas cylinder dryers can ensure the same drying performance as the FIT machine produces on the pressure test side.
Customers requesting the integration of a CIL dryer typically opt for the FIT50-DUO pressure testing bench. This allows for pressure testing on one bottle rotator while bottles are being dried on the other. The alternating operation saves operator time.
DRY-VAP
The operating principle is as follows: first, hot, dry steam is blown into the gas cylinders, followed by hot, dry air. The DRY-VAP can only be supplied integrated into the pressure test bench. All FIT models can be equipped with DRY-VAP drying.
The gas cylinders are dried upside down after emptying. Drying 6 x 50-litre gas cylinders takes approximately 9 minutes.
Our customers using the FIT-6DUO-EVO + DRY-VAP system can test approximately 30 gas cylinders per hour with 1 operator. The DRY-VAP ensures high drying output.
After using DRY-VAP, the residual moisture level measured in the gas cylinders was 40 PPM on average with nitrogen at 50 bar.
Special machine
If it is necessary to inspect the deformation of the gas cylinder during or after the pressure test, then we recommend our WINJ72 water-jacket pressure testing machine.
The machine measures and optionally records the degree of deformation of the gas cylinder. The machine can handle 1 water jacket at a time. The test takes approximately 1 hour per cylinder. Therefore, customers typically use 2 water jackets: while one is in use, the other cylinder can be prepared.
