Automatic vs. Manual Air Release Valves in Petrochemical Systems: Which Is Better?

Quick Overview: What’s the Difference?

1. How Automatic Air Release Valves Work

Automatic air release valves are designed to detect and vent air without human intervention. They operate using float or pressure mechanisms that open the valve when air accumulates and close it once fluid returns.

Key Benefits:

• Hands-free operation—ideal for remote or hazardous areas
• Maintains system performance 24/7
• Reduces risk of air build-up during peak operations
• Prevents water hammer and flow irregularities
• Essential for systems with constant flow or pressure changes

Common Use in Petrochemical Settings:

• Offshore firewater systems
• Pressurised pipelines with elevation changes
• Critical lines where manual intervention isn’t practical

2. How Manual Air Release Valves Work

Manual air release valves require an operator to open the valve manually to vent air from the line. These are simple in design and often installed with isolation valves for safe access.

Key Benefits:

• Lower upfront cost
• Simple, rugged design with fewer components
• Useful in systems that don’t run continuously
• Good for controlled or supervised environments

Common Use in Petrochemical Settings:

• Small, infrequently used lines
• Commissioning or maintenance tasks
• Locations with regular inspection teams

3. Side-by-Side Comparison

4. Cost vs. Risk Considerations

While manual valves offer a cost-effective solution, the trade-off is greater reliance on human oversight, which can pose challenges in high-risk petrochemical environments where:

• Quick air release is critical for pressure stability
• Operators may not be immediately available
• System failure during an emergency (e.g. firefighting) is unacceptable

In these cases, the higher initial cost of an automatic valve is easily justified by reduced maintenance, greater reliability, and safety assurance.
 

5. Material & Design Considerations for Both Types

Regardless of operation type, the valve body material must match the harsh demands of petrochemical service—especially in seawater applications.

At GA Valves, we manufacture both automatic and manual air valves in:

• Super Duplex Stainless Steel
• 6Mo (Alloy 254 SMO)
• Titanium
• Hastelloy
• Aluminium Bronze

These materials are specifically selected for corrosion resistance and long-term durability in fire-fighting systems and petrochemical plants.
 

Conclusion: Which One Should You Choose?

✔️ Choose Automatic Air Valves if your system:

• Operates continuously
• Uses seawater in fire suppression or cooling
• Is installed in remote or difficult-to-access areas
• Must remain operational during power loss or emergencies

✔️ Choose Manual Air Valves if your system:

• Runs intermittently
• Is easy to access and inspect regularly
• Requires a cost-effective short-term solution
• Is non-critical or supervised frequently