Other Industries | York Refrigeration

York Refrigeration introduces new pressure test installation, enabled by Emerson Process Management's DeltaV and AMS

Sabroe Refrigeration, known as one of the largest suppliers of industrial and maritime cooling systems, has been taken over by York International Corporation. Sabroe Refrigeration produces cooling compressors, containers and finished condensing units for the cooling industry, today under the name of York Refrigeration. York Refrigeration has more than 6,800 employees with branches all over the world and a yearly turnover of approximately Dkr 8 billion.

The products are sold throughout the global market and cover both land-based and maritime applications. In order to meet all requirements for pressure testing and certification from customers in different countries on the global market, it is necessary to maintain a considerable test- and certifying system.

York Refrigeration found that the pressure testing, which is part of the continuous production control and the final certification, has been a bottleneck during the production sequence and also a considerable expense. Previously, the pressure testing was carried out as a hydro test using water. However, by using this procedure, it was necessary for the tested items to dry out, which required a lot of time and a huge amount of energy for heating and for air transportation during the drying process.

In order to eliminate the bottleneck problem it was decided to modify the pressure test procedure and use compressed air instead of water. This procedure would eliminate both the bottleneck problem and the energy consumption required by the drying process. This solution demanded a modification of the test chambers as any error in the test items followed by an explosion had to take place in a safe environment without any risk of personal injury. When building the test chambers, it was therefore decided to use reinforced concrete, (similar to a Second World War bunker), which could resist an explosion of the tested item as big as a 15 cubic meter vessel and at the same time relieving the surplus pressure without exceeding the noise limit stated by the local authorities.

A close co-operation concerning the functionality and construction of the test chambers between Emerson Process Management, who was in charge of the pressure testing including control and registration, Dansk Trykluft Industri who handled the compressed air supply and the end-user began as early as the planning phase.

The most important aims for the construction of the chambers were:

• It should be possible to execute several independent pressure tests simultaneously in each chamber to eliminate the bottleneck problem.



• It was necessary to fulfil the requirements of the different authorities and accredited agencies concerning the execution of the pressure tests with regard to tests, certification and the safety issues during the testing itself.



• The tests and procedures should be traceable and a part of the end-user's ISO 9000 system. This is maintained by the AMS package via the DeltaV digital automation system.

Safety loops verify that the test chambers are fully closed and locked before it is possible to carry out a test sequence and enables at the same time that any pressurized items are relieved to the atmosphere should a fault occur during a test sequence. The compressed air for the chambers is supplied dry and oil-free by separate high-pressure compressor stations. The supply from these can be cut off if an error occurs.

The actual pressure tests are started by connecting the test items to the respective test outputs in the test chamber and sealing off the chamber. The test specifications for each test sequence are then loaded into the DeltaV station.

If the safety loops are ok, it is possible to start the test sequences. The safety loops controls, among other things, that the large doors into the chambers (each 4,000 kg in weight), are closed and pressurized to avoid leakage. All sequences are started simultaneously and when all test sequences are finished it is possible to open the chamber. During the test period all test results are logged and related curves are printed out. The curves verify that during the test period the pressure level is subject to the specified requirements according to the relevant standard with regards to pressure levels and to test time. The master pressure transmitter is used for verification of the pressure registration to the national standard. The test result follows the respective vessel or compressor as documentation as defined in York Refrigeration's ISO 9000 system.

As part of the approval by the authorities for the construction of the first large pressure chamber, an explosion of a vessel, whose size was specified by same authorities, was performed after the vessel had been weakened.

The test did not go by unnoticed -- several mobile alarms in the neighbourhood started off due to vibrations transferred underground. However the noise limit was not exceeded and the chamber was approved.

Jan Marcussen, Quality Director with York Refrigeration says that the aim of eliminating the bottleneck problem and reducing energy costs was fulfilled 100% due to the modifications of the test procedure and the construction of the test chambers. The investment in connection with the modification of the test procedure, is expected to be covered within the originally fixed time schedule based on the savings of energy consumption alone. However the biggest advantage is the elimination of the bottleneck problem itself as the new procedures have made it possible to increase production by around 150%.

"Considering all aspects, the project has been an unconditional success," says Jan Marcussen.

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