The philosophy of FAI design is not only limited to complying with the code but it also focuses on the fatigue life of the closure assembly and its components, including the gasket. It is a well-known fact that to reduce the stress in the closure components, it is common practice to minimize the elastic deformation. FAI has evaluated the distribution and localization of the stresses in each component. Based on FAI’s knowledge and regardless of the specified steel grade, the stress parameters assumed in the calculation are significantly below the allowable limit and, as a result, each component is effectively redundant.
This approach enables FAI design to have a sturdy construction, suitable to properly withstand any unforeseen peaks of stresses.
The shelf-life of the gasket, whichever the geometry or the type of elastomer used, is generally double lasting. Structural components, such as the hub, the door and the clamps, are made of CTOD-supported steel. The selected materials, basically forging, are characterized by “low cycle fatigue test” so that they suit fatigue cycles.
The choice of the correct steel, in addition to fabrication details, secures a 30,000 life cycle.
Main Features
Optional Features
As standard feature, the FAI “Bayonet” End Closure is spark proof and vacuum duty.
In addition, through an implementation of minor modification, the FAI end closures suit different services such as:
- Fire safe
- Gas Sealing (cyclic gas service)
- Cryogenic service
- Fatigue life (FAI quick closure is granted for 30,000 cycles from zero to design pressure)
To demonstrate the suitability to withstand these services, dedicated tests have been developed in house under Third Party supervision for certification purposes, while capability tests are always available for:
- Pneumatic cyclic gas leaking test by nitrogen or helium up to 430 barg
- Hydrotest in cooled box under cryogenic condition
- Cyclic pressure test (continuous recorded) to simulate fatigue test over 30,000 cycles (from 0 to 250 barg) for quick closure working in dyeing sector.
Additional instrumentation can be designed and supplied in support of the closure:
- key interlock
- proximity switch
- control system
When required or due to heavy sizes, operation may be assisted and supported by:
- hydraulic or electrical opening/closing
- mobile pneumatic tool
;
Additional Safety Features
The design of the FAI “Bayonet” End Closure has also been improved to ensure that, after the system depressurization and the safety device open, the possible presence of liquid static head cannot cause any undesirable door slam.
Upon request, a double gear system allows the door opening in two steps: the first to nullify the Gasket asset and guarantee, in the event of liquid static head, to maintain the teeth engaged. The liquid, if any, is free to drop through the drain hole located in the bottom segment of the clamp, giving a warning signal to the operator.
The second step allows the complete safe opening of the door.
Any additional monitoring device can be provided upon request.
Environment
The design of the FAI “Bayonet” End Closure has also been improved to ensure that, after the system depressurization and the safety device open, the possible presence of liquid static head cannot cause any undesirable door slam. Upon request, a double gear system allows the door opening in two steps: the first to nullify the Gasket asset and guarantee, in the event of liquid static head, to maintain the teeth engaged. The liquid, if any, is free to drop through the drain hole located in the bottom segment of the clamp, giving a warning signal to the operator. The second step allows the complete safe opening of the door. Any additional monitoring device can be provided upon request.