Tennessee Wastewater Operator Practice Exam

How should threaded air diffusers be attached to the headers?

1. Weld them in place

2. Manually screw them on until finger tight

3. Use a power tool to tighten them

4. Seal them with adhesive

The correct answer is: Manually screw them on until finger tight

Threaded air diffusers should be attached to the headers by manually screwing them on until they are finger tight because this method ensures a proper seal without over-tightening, which can damage the diffuser or the header. Manual tightening allows the operator to feel when the diffuser is seated correctly, minimizing the risk of leaks that can occur if the connection is not snug. This method also helps in avoiding undue stress on the materials that could lead to cracking or warping. In contrast, using a power tool to tighten could easily result in excessive torque, risking damage to the threads or the fittings. Welding the diffusers in place would be inappropriate as it creates a permanent attachment that complicates maintenance and replacement. Similarly, sealing them with adhesive could make future repairs difficult and does not typically provide the necessary flexibility needed for these connections in wastewater systems, where expansion and contraction may occur due to varying temperatures and pressures. Thus, the manual approach offers the best balance of security and maintainability.