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BELLOW CONSTRUCTION & LEAK MONITORING The critical operating conditions create challenging requirements in regards to the design of the FCCU Expansion Joints. The Expansion Joint is a key component in the pipe system and the careful selection of bellow material is important. The selection of the most suitable material is often done accord- ing to customer requirements, the specification and/or based on experi- ence. Bellows forming The bellows are normally formed either by punching or hydraulic forming. 2-ply testable bellows Double ply or redundant ply bellows are widely used for FCCU applications. Simple double ply bellows utilises the strength of both plies to withstand the operation conditions. Redundant ply bellows are designed in such a way, that each ply will be able to take up the full load. So if the inner ply is leaking the outer ply will be able to take up the load and operate until the next shutdown. Monitoring An option is to use control rods which monitor the complete system. The control rods are mounted over the bellows and monitor the movements. If the insulation is worn out, the heat will increase and this higher temperature will result in larger movements. Leak monitoring This solution gives good monitoring options as well as increasing opera- tional safety. The two-ply design is monitored through a leak indicator (pressure gauge monitor). A redundant ply design offers even better safety and monitoring options, as the unit stays under operation until the scheduled outage even in the event of a minor leakage. Redundant ply bellows are calculated in a way that the single layer would be able to carry the full load alone. In other words, if the inner layer fails, the outer ply would be able to secure operational safety of the Expansion Joint until a scheduled shutdown. Additionally, the Expansion Joints are fitted with a pressure gauge monitor indicating the failure of the inner ply. Generally speaking there are two types of monitors: • Passive monitor If the inner ply fails the monitor is activated by the increasing pressure between the plies. This monitor will only indicate the failure in an inner ply. • Active monitor A vacuum is created between the inner and the outer ply before installing this monitor. If the inner ply fails the pressure between the plies will activate the monitor. If the outer ply fails the monitor is activated by the loss of vacuum. This monitor can detect failures on both the inner and the outer ply.
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REFRACTORY LINING Refractory lining is an important element of FCC Expansion Joints and FCC components. Belman can arrange for the refractory lining and thereby deliver the complete FCCU Expansion Joint. However, should the client prefer, they can arrange for the refractory lining themselves. Belman work with the best companies within refractory lining to ensure high quality, suitable linings for the application. Thereby ensuring the smooth operation without any costly unexpected shutdown. Belman meets the refractory lining specifications from licensors specifications in the same way as for the design of the complete unit. Refractory materials Belman always selects the refractory lining specified and/or requested by the client such as eg. Resco. Installation of refractory lining The insulation and the refractory lining is provided in accordance with the specifications and agreements with the client. Belman can install by casting, gunning (pneumatic application), hand-placing or pneumatic ramming. Belman is experienced with the provision of anchoring systems such as hexmesh etc. We work only with best in class refractory lining companies that have the same levels of quality control and knowhow as Belman. Only the best. Belman works only with the best, high end brands concerning refractory lining. The partners selected for refractory lining are located very close to Belman.
