The allowable vibration tolerance for a double flange butterfly valve (often abbreviated as DFBV or DFV) can vary depending on several factors, including the valve size, design, application, and industry standards or specifications. Generally, valve manufacturers provide vibration tolerance specifications based on their engineering design and testing.

The allowable vibration tolerance is typically expressed in terms of vibration amplitude, frequency range, and duration. For example, it may specify maximum allowable vibration amplitudes in terms of displacement, velocity, or acceleration at certain frequencies, di butterfly valve measured at specific locations on the valve body or components.

To determine the specific allowable vibration tolerance for a double flange butterfly valve, it’s essential to refer to the valve manufacturer’s technical documentation, such as product datasheets, installation manuals, or engineering specifications. Additionally, consulting relevant industry standards, such as those from organizations like the American Petroleum Institute (API), the International Organization for Standardization (ISO), or the American Society of Mechanical Engineers (ASME), can provide guidance on acceptable vibration levels for different types of valves in various applications.