In pressurized piping systems, air release valves play an essential role in maintaining smooth, efficient operation and protecting equipment from damage. Below is a refined, more technical overview to help you understand when, why, and how to use them — plus tips for sizing, placement, and maintenance.
Trapped air in pipelines is more than just an annoyance — it causes a host of problems:
Flow disruption & head loss: Air collects at high points, blocking or restricting fluid flow, forcing pumps to work harder.Air gets into a system from several sources:
So the goal is clear: continuously and automatically remove collected air to maintain system integrity. Valves such as the Val-Matic Clean Water Air Release Valve and Val-Matic Wastewater Air Release Valve are specifically designed to perform this function reliably in both clean and dirty service conditions.
An automatic air release valve is simple in principle:
This cycle repeats continuously. Key design considerations:

Products like the Val-Matic Clean Water Air Release Valve are ideal for potable or process water applications, offering precision venting and corrosion-resistant materials. For more demanding conditions such as wastewater or sludge lines, the Val-Matic Wastewater Air Release Valve is engineered with large orifice designs and anti-clog features to handle solids effectively.
Air release valves are best for closed, pressurized systems where small or moderate volumes of air need to be vented. Typical use cases include:
Because the orifices are relatively small, they’re ideal when air volumes are moderate. For large-volume venting — e.g. during filling or rapid drainage — you may want to pair them with air/vacuum valves or combination air valves that handle both intake and exhaust in large flow conditions.
For example, the Val-Matic Clean Water Air Release Valve can be placed at system high points to prevent air locking in municipal or industrial water lines, while the Val-Matic Wastewater Air Release Valve is well suited for sewer force mains or any system carrying solids-laden fluids.
Advantages
The Val-Matic Wastewater Air Release Valve includes design features that minimize fouling and allow for easier maintenance, while the Val-Matic Clean Water Air Release Valve provides a high-performance option for systems where clean, corrosion-free service is essential.
To get the right air release valve:
For most water and wastewater applications, Crane Engineering recommends the Val-Matic Clean Water or Wastewater Air Release Valves, depending on the fluid medium and solids content.
Both Val-Matic Clean Water and Wastewater Air Release Valves are designed for straightforward maintenance with easy access to internal components and long-lasting float mechanisms, reducing downtime and service costs.
Trapped air in piping systems is a silent threat to performance, reliability, and safety. Installed properly, automatic air release valves dramatically reduce those risks by maintaining near air-free flow, protecting equipment from pressure surges, and improving operational efficiency.
If your system is showing pressure spikes or suspect losses in flow, evaluate whether proper air release valves are in place — and whether those in place are sized and maintained correctly. Reach out to the team at Crane Engineering for help selecting and applying Val-Matic Clean Water or Wastewater Air Release Valves for your system today!
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