Sesimic Qualification Service for Butterfly Valve from ProSIM
ProSIM works as Nuclear Seismic Qualification consultant from Bangalore India. ProSIM has been supporting all manufacturers and contractors for seismic qualification service over last 2 decades and have submitted more than 800 seismic reports to various entities of Department of atomic energy including nuclear power corporation (NPCIL), Baba Atomic Energy Center (BARC), Indira Gandhi Atomic Energy Research Center (IGCAR).
Seismic qualification of a butterfly valve involves evaluating its ability to withstand seismic events, such as earthquakes, without losing its functional integrity. This is critical for ensuring the safety and reliability of piping systems in nuclear power plant facilities that are located in seismic zones. Here are the key steps and considerations in conducting a nuclear seismic qualification of a butterfly valve:
- Understanding the Valve Design:
– Gather detailed information on the butterfly valve, including its materials, dimensions, operating pressures, and installation configuration embedded in GAD, PID, ISO, design drawings, CAD models, etc.
– Identify the mounting method (flanged, lugged, wafer, or double-flanged) and the orientation of the valve in the system.
- Seismic Qualification Requirements and Standards:
– Determine the applicable seismic standards and codes. Common standards include ASME B31.3, ASME BPVC- especially Section III, IEEE 344, and various local building codes. In Indian context, documents such NPCILs PP1819 and AERB SGD O23 are also to be considered.
– Define the seismic design criteria based on the seismic zone, site-specific conditions, and criticality of the valve in the system.
- Seismic Analysis FEA:
– Develop a finite element model of the butterfly valve, including the body, disc, stem, and seals.
– Apply the seismic loadings to the model. These loadings are usually defined in terms of acceleration spectra obtained from site-specific seismic hazard analyses.
- Dynamic Analysis:
– Perform modal analysis to determine the natural frequencies and mode shapes of the valve.
– Conduct response spectrum analysis or time-history analysis to evaluate the valve’s response to seismic events. This involves applying the seismic acceleration spectra to the valve model and calculating the resulting stresses, displacements, and accelerations.
- Structural Integrity Assessment:
– Analyse the results of the dynamic analysis to identify any critical areas where stresses exceed allowable limits as defined in codes.
– Check for potential failure modes, such as yielding, buckling, or fatigue.
- Functional Assessment:
– Ensure that the valve can still operate as intended during and after a seismic event. This includes verifying that the valve can open and close without excessive friction or deformation.
– Evaluate the impact of seismic loads on the actuator, if present, and ensure it remains functional.
- Design Improvements:
– If the seismic analysis FEA results indicate that the valve does not meet seismic qualification requirements, consider design modifications. These may include reinforcing the valve body, changing materials, or adding supports and restraints.
- Validation and Testing:
– Validate the analysis results with physical testing, if feasible and if needed by the codes/ guidelines. This could involve experimental methods such as shake table tests to replicate seismic conditions.
– Compare the test results with the analytical predictions to ensure accuracy.
- Documentation and Compliance:
– Document the entire nuclear seismic analysis process, including assumptions, calculations, results, and any design changes.
– Ensure compliance with the relevant standards and obtain necessary certifications or approvals.
By following these steps, engineers can ensure that butterfly valves are capable of withstanding seismic events and continue to function reliably in critical applications.
- ProSIM Offerings in Valves manufacturers
ProSIM is an engineering design services company. ProSIM provides engineering outsourcing services to valve manufacturers as engineering design consultants. As part of its basic engineering service and detailed engineering service, ProSIM has worked with manufacturers producing variety of valves as well as EPC contractors using valves. Range of engineering service outsourcing activities related to valves include:
- Valve selection and sizing
- Design calculations
- FEA services (including CFD)
- Nuclear seismic analysis and seismic qualification
- Code check and qualification
- Design optimisation to achieve functional requirements.
