PTQ Q1 2024 Issue

Figure 6 Installed scraping and sealing solution for a floating roof tank

cable (thermowire) can often generate false alarms. This uncertainty is a sign of low sensor reliability and creates a challenge for operators, who must decide when and how to intervene. It is important to decide whether the system should be turned off immediately or, if a false alarm is suspected, the field cause of the alarm should be verified. In the former case, restoration of the area under consideration would result in high costs. Over time, multiple false alarms can cause staff to con - sider a system unreliable and, therefore, of little use. The third option would mean, in case of ignition, a delay in acti - vating the fire extinguishing system with its related conse - quences. To avoid these problems, it is therefore necessary to maintain detection systems with technical features that are immune to false alarms and can respond immediately. Moreover, by continuously monitoring the temperature near the seal, valuable information about the wear of the seal can be provided to the operator, allowing for interven - tion prior to a critical situation arising. Advantages include: • Increased level of security • Self-recovery sensor after the intervention of the alarm • Reduced cost of insurance premiums, as the provision of prevention systems reduces the level of risk, thus increas - ing the level of security. Bob Poteet is Director of Business Development for the Global Project Business group at WIKA, Houston, Texas. He graduated from Texas A&M University. He has four patents in temperature sensing areas used in the process industries. Andrea Biava is Business Development Manager for Electrical Temperature and Services at WIKA Italia. • Increased functional efficiency and durability • Programming of maintenance interventions Haytham Al-Barrak is a Fired Equipment Engineering Consultant at Saudi Aramco. He holds an MS in mechanical engineering from University of Southern California. He has two patents in fired equip - ment monitoring. Mahendran Sella is a Heat Transfer and Combustion Engineer at Saudi Aramco. He holds a BS degree in mechanical engineering from Institute of Engineers, India.

Figure 5 Multi-zoned RDS unit installation

zones. The sensors are run vertically over the full unit and at the top. • Steam methane reformers (SMRs): The outlet header in an SMR is a refractory line piping that requires constant monitoring of the outside temperature by operators. Some use thermocouples, while others just do scanning. A com - mon question related to thermocouples is how many are needed to give complete coverage while the scanning is a real Opex cost. For this solution, we can simply wrap the pipe with the RDS and monitor for any refractory failures. This can be easily installed with a clamping system or even magnets. • Floating roof oil storage: There have always been con - cerns about the possibility of generating a fire in a floating roof tank (see Figure 6 ). For their conformation, these tanks have a mobile roof that slides along the vertical axis of a metallic structure fixed cylindrically. To avoid product leaks during the sliding of the roof, a scraping and sealing system (seal) is installed. The seal, made of rubber, undergoes con - tinuous mechanical vertical movement and is exposed to corrosive agents contained in the product, usually hydrocar - bons. Over time, it deteriorates and emits vapours released by the stocked product, which is normally maintained in the tank at a variable temperature between 70°C and 90°C. Under certain climatic conditions, this escape of vapours can trigger fires that cause significant damage to plants, the environment, and staff. Protecting these tanks with fire detection systems is therefore essential. However, deteri - oration of the coating material of the linear heat detection

PTQ Q1 2024