Valves are a key component of most fluid delivery systems. A firm understanding of compressor valve dynamics helps technicians analyze problems, devise solutions, and choose the correct parts. The science of compressor valve dynamics allows installers to design efficient, reliable solutions in new installations.
The Heart of a Compressor Valve
Although the functionality of valves is quite simple, the implementation of valves can be somewhat complex. The valve generally consists of a circular disk with a beveled edge. The valve seats at the top of a hollow cylinder with a matching bevel. A spring forces the valve disk onto the seat.
The valve spring works in opposition to the fluid flow force. This force has two components. The first results from the viscosity of the fluid flowing between the valve and seat bevel. The other comes from the suction force as the valve moves toward or pulls away from the seat. These forces contribute to the key factors of valve design, including:
- Proper valve timing
- The immunity of the valve to flutter
- The reliability and lifetime of the valve
Dealing With Compressor Valve Flutter
Valve flutter is one of the major contributors to degradation in performance and lowering of reliability. The mechanism is not unlike swinging a baseball bat against a well-seated metal pole. At the moment the bat strikes the pole, there is a chatter that sends a high frequency vibration up the arms of the person swinging the bat. This happens because the bat does not reach a dead stop when it first hits the pole, but bounces just a little.
Valve flutter is also a high frequency opening-and-closing action that works against a smooth and solid valve close action. It also increases the stress and wear of the valve components.
Well-designed components eliminate flutter by manufacturing the specifications to a specific window of operating conditions. Technicians can ensure high-performance, high-reliability installations by carefully choosing the valve which matches the specific conditions of the installation. For complex systems, designers often work with the on-site engineers at the provider site to ensure proper part selection.
