In modern industrial production, the safety of storage tanks and pressure
vessels is a crucial aspect. Excessive internal pressure or vacuum can lead to
catastrophic equipment failures, such as tank rupture or implosion. Vacuum
Relief Valves, which are usually integrated with pressure relief functions in a
single device (namely Pressure Vacuum Relief Valves, PVRV), serve as critical
protective devices to ensure the structural integrity and operational safety of
storage tanks.
Working Principles of Vacuum Relief Valves
Understanding how valves respond to pressure changes to protect tank
safety
Core Functions
The core function of a vacuum relief valve is to allow external air to
enter the storage tank when the internal pressure of the tank is lower than the
external atmospheric pressure, thereby balancing the pressure difference between
the inside and outside and preventing the tank from implosion or damage due to
negative pressure. This process is commonly referred to as "breathing in".
Key Components
| Component | Function Description |
|---|
| Valve Body | The main structure of the valve that provides fluid passage |
| Seat/Disc | Precisely machined sealing components that prevent gas leakage when the valve is closed |
| Spring | Provides preset closing force and determines the opening pressure or vacuum degree of the valve |
| Guide System | Ensures the disc moves smoothly and vertically during opening and closing processes |
| Set Pressure Adjustment Device | Used to accurately set the pressure or vacuum value that triggers valve response |
Working Process
Normal State: The internal pressure of the storage tank is maintained
within the set range, and the disc is tightly pressed against the seat.
Vacuum Formation: Pressure inside the tank drops due to discharging
operations or temperature decrease, creating negative pressure.
Valve Opening: When the vacuum degree reaches the preset value, external
atmospheric pressure pushes the disc open.
Air Inflow: External air enters the tank through the opened valve to
supplement internal pressure.
Valve Closing: After pressure is restored, the spring pushes the disc back
onto the seat, re-establishing the seal.
Performance Indicator: Many high-performance valves are designed to achieve
full open status when the pressure or vacuum degree exceeds the set value by
10%, so as to maximize the release or intake flow rate.
Analysis of Basco Vacuum Relief Valve Products
A range of high-performance products from a world-leading manufacturer
Basco is a leading manufacturer in the field of pressure protection
equipment, whose products are widely used in petroleum, chemical, pharmaceutical
and many other industries. Its PVRV series is renowned for high precision, low
leakage and superior reliability.
The product line includes the Model 5400 Vacuum Relief Valve and the Model
5200 In-line Valve.
Product Features
Dual-guide rail system ensures smooth stroke and minimal wear
Leakage rate is far lower than the API 2000 standard
Setting accuracy up to ±3%
Full opening at 10% overpressure
Cartridge and seat assemblies can be replaced on-site
Application Fields and Importance
Pressure vacuum relief valves are critical equipment for ensuring safe
production and environmental protection, with applications spanning across
multiple key industrial sectors.
Oil and Gas: Prevent pressure fluctuations in storage tanks and pipelines
caused by temperature changes.
Chemical Manufacturing: Protect storage tanks containing volatile or
hazardous chemicals.
Food and Beverage: Maintain stable pressure environments in fermentation
tanks and storage vessels.
Pharmaceuticals: Precisely control pressure in sterile production
environments.
Water Treatment and Biogas: Release gases generated during biological
reaction processes.
Aerospace/Defense: Key applications requiring high reliability.
Key Values
Prevent equipment damage and extend service life
Reduce economic losses caused by material evaporation
Minimize environmental pollution and comply with environmental
regulations
Meet requirements of industry standards such as API 2000
Conclusion
Although vacuum relief valves have a simple structure, they play an
indispensable role in ensuring the safety of industrial storage tanks and
pressure systems. Through precise mechanical design, they can automatically
respond to pressure changes and reliably protect equipment from negative
pressure damage.
Modern high-performance products represented by Basco's Model 5400 and
Model 5200 valves achieve enhanced sealing performance and operational
reliability by adopting advanced materials and designs, meeting the stringent
requirements of different industrial application scenarios. The correct
understanding, selection and maintenance of these critical safety components are
the foundation for ensuring the safe, efficient and compliant operation of any
industrial process involving pressure vessels.
