Author: MIKE PREVOST, Vice President of Professional Services, Ohmstede Industrial Services
Bolted flange joint connections should not leak on the heat exchanger, but they often leak due to design and/or assembly issues. However, by paying due attention to the factors that have the greatest impact on the bolted connection, a leak-free connection can be achieved on the heat exchanger.
A leak-free connection can be achieved on the heat exchanger.
Before disassembly, there are several key factors that need to be considered to avoid flange joint leakage. First of all, we must understand the temperature, pressure and influence of product performance on bolt flange joints, and then choose suitable materials and gaskets.
Identify any areas of concern. In this evaluation stage, consider whether existing bolts, nuts, and washers are the best choice based on the temperature, pressure, and service of the heat exchanger.
After disassembly, pay attention to the location of the existing gasket and any signs of corrosion or pitting on the flange face surface. In addition, verify the flatness of the mating surface. Following the recommendations made in ASME PCC-1 can prevent many problems. After verifying the gasket surface, the next step for the staff is to verify that they have the correct washers, bolts, nuts, and (if applicable) washers, and the correct lubricant. Just like airline pilots have pre-flight checklists, it is a good practice to have flange joint inspection and verification checklists to help eliminate potential problems during the disassembly and reassembly of the switch.
Bring engineering and flange assemblers together
Effective assembly of bolted flange joints requires more than just putting their hands on the flange. It all starts with engineering design and determining the right materials for process applications. Then the engineering design parameters must be effectively communicated to the assembler to have the greatest impact on the quality of the results.
There is no substitute for knowledgeable and qualified bolt fitters. The way to ensure proper assembly is to ensure that the assembly personnel are experienced and understand the good, bad and ugly on site. A key factor in achieving a leak-free exchanger is to ensure that both engineering and qualified and experienced assemblers are involved in the process.
By following the ASME PCC-1 guidelines and using well-trained bolting personnel, the owner can significantly increase the likelihood of achieving a leak-free switch. A key reason for using certified bolting personnel is because they will check and resolve:
Flange joint connection is dynamic, but as long as it is correctly understood, managed and applied, there are many opportunities to achieve leak-free performance on heat exchangers. By following the ASME PCC-1 guidelines and using qualified bolting personnel, the probability of achieving a leak-free exchanger is greatly improved. From a technical and application point of view, we invite readers to contact Ohmstede Industrial Services, one of the industry's leading heat exchanger maintenance contractors, for your next project.
For more information, please visit www.ohmstede.com or call (281) 867-3260.
Author: MIKE PREVOST, Vice President of Professional Services, Ohmstede Industrial Services
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