Blog Post

Tank vents play a critical role in the safe and efficient operation of storage tanks across various industries. Whether storing water, chemicals, fuel, or other liquids, proper venting is essential to prevent overpressure, vacuum conditions, and environmental hazards. This article explores what tank vents are, how they work, and why they are vital for modern tank systems.

What Are Tank Vents?
Tank vents are safety devices installed on storage tanks to allow air or gases to enter or exit the tank as the internal pressure changes. These vents help maintain atmospheric pressure inside the tank during filling or emptying, preventing structural damage and ensuring smooth operation.

There are various types of tank vents, including:

• Pressure Relief Vents – Release excess pressure to prevent over-pressurisation.

• Vacuum Relief Vents – Allow air into the tank when internal pressure drops below atmospheric levels.

• Pressure/Vacuum Relief Vents (PVRVs) – Provide both pressure and vacuum relief in a single unit.

• Free Vents – Allow unrestricted airflow for tanks that do not require pressure or vacuum protection.

Why Tank Venting Is Important
Proper tank venting serves several crucial functions:

• Prevents Tank Damage: Avoids deformation, rupture, or collapse due to pressure fluctuations.

• Ensures Safe Operation: Reduces the risk of explosions or chemical exposure.

• Protects the Environment: Minimises emissions of hazardous or volatile vapours.

• Maintains Product Quality: Prevents contamination by keeping a stable internal environment.

• Supports Compliance: Meets safety and environmental regulations (e.g. AS/NZS, API, EPA standards).

Industries That Rely on Tank Vents
Tank vents are used in a wide range of industries, including:

• Petrochemical and Oil & Gas – For venting large fuel or chemical tanks.

• Water and Wastewater Treatment – Prevents vacuum and overpressure in holding tanks.

• Agriculture – Used in fertiliser and water storage systems.

• Pharmaceuticals – Maintains sterile conditions and pressure balance.

• Food & Beverage – For venting storage tanks during filling and emptying.

How to Choose the Right Tank Vent
When selecting a tank vent, consider the following:

• Tank Size and Type

• Operating Pressure and Vacuum Requirements

• Nature of Stored Material (corrosive, flammable, volatile, etc.)

• Location (indoor, outdoor, hazardous zones)

• Regulatory Requirements

• Vent Flow Capacity (SCFH or m³/h)

Materials used in vent construction—such as stainless steel, aluminium, or PVC—should also be compatible with the stored media to prevent corrosion or damage.

Advanced Features Available in Modern Tank Vents

• Flame Arrestors for explosive vapour protection

• Pressure and vacuum setting adjustability

• Weather hoods or insect screens

• Smart sensors for monitoring tank pressure and emissions

Conclusion
Tank vents are an indispensable part of any storage tank system. By allowing proper airflow and pressure regulation, they ensure safety, extend tank life, and keep operations compliant with regulations. Investing in high-quality tank vents is essential for any facility handling liquids or gases in bulk.