Fully automatic HP Butterfly
valve testing
A large international valve manufacturer placed the enquiry for a fully automatic test unit for their newly opened metal seated, triple offset butterfly valve production in Slovenia. The high quality valves where produced in small series and as final step of the production, the valves have to go through a large number of pressure and performance tests.
In modern valve manufacturing time is of the essence and therefore the role of the operator was supposed to be limited to loading and unloading of the test objects.
Range: Triple offset high performance Butterfly valves 3 – 16” / Pressure Class 150 – 600
Testing: Fully automatic pressure and performance testing 0 – 200 bar / 0 – 7,500 Nm.
The challenges
Although it concerned a relative simple application with a small range of HP Butterfly valve types and sizes, the Ventil Engineered Solutions team faced a number of challenges.
Full automatic testing means that the intuitive intervention of the operator’s eyes and hands is replaced by ‘CNC’ technology and this isn’t always as easy as you may think.
Having all disciplines available in-house enabled us to accept the challenge and combine smart process controls with intelligent software to develop this unique machine.
The first challenge was to facilitate a quick and efficient (un)loading procedure. Small valves could be quickly (un)loaded by hand, but the larger – high pressure class types had to be (un)loaded by crane. For this purpose the clamping fixture was equipped with a rail mounted loading system. The bottom sealing adapter rails-out for easy (un)loading outside the test bay. A study concluded that within the variety of valves there were no ‘reference surfaces’ for quick and easy positioning and alignment of the ‘bare shaft’ valve. The solution was found in laser light, projecting a strong red stripe on the valve, helping the operator to quickly align the valve.
The Ventil IT engineers developed special ‘CRS’ test software to run the full automatic sequence and enable the operator to undertake other activities while the valve is being tested. All steps of the test sequence where meticulously programed to run the full automatic sequence. A ‘test recipe’ was made available for programming the complete test procedure for each valve type and size. This enables the user to make future adaptions and program new valves.
The first initial step, prior to pressure testing was the measuring of the quarter turn, opening and closing torque to measure and prove that the valve is correctly assembled. The required pass and fail tolerances with this test where found between only several Nm’s and this required highest sensitivity and measuring accuracy. For this special application the Ventil Engineered Solution team developed new hard and software for the 7,500 Nm strong drive system. During the CNC test sequence the test stage and actual measuring data are shown on the CRS screen. The hydrostatic body test, bi-directional seat testing and high pressure open/close performance (torque) tests are automatically executed. The operator can follow the test on the screen, but assistance is only needed when a deviation is detected.
A complete range of test objects for testing the test unit was not available yet. Therefore the machine ‘fine tuning’ had to take place on-site, after installation and commissioning. Having remote access to the test unit’s operating system enabled the Ventil engineers to quickly respond and implement upgrades to reach the ultimate machine performance and output.
Get in touch
Do you have questions about a certain project or you have a similar challenge in hands?
Get in touch with the Ventil Engineered Solutions team.
