The tell-tale hole for the stem O-ring is located on which part of the system?

The tell-tale hole for the stem O-ring is located on which part of the system?

• A. Inside the control panel
• B. Top of the pump
• C. Rim of the service tank
• D. Side of valve body on SOPV

Answer: (D)

A tell-tale hole is a built-in leak indicator for the stem packing. If the stem O-ring starts to fail, fluid from around the stem will escape and become visible through this hole. It’s placed on the side of the valve body on the SOPV so the indicator is easy to observe while the valve is in service, without disassembly. Seeing fluid there means the packing or O-ring needs attention and replacement or repacking to stop the leak. The other locations wouldn’t provide a direct, easily observable indicator of stem packing leakage, so this side-of-valve placement is the practical choice.

A tell-tale hole is a built-in leak indicator for the stem packing. If the stem O-ring starts to fail, fluid from around the stem will escape and become visible through this hole. It’s placed on the side of the valve body on the SOPV so the indicator is easy to observe while the valve is in service, without disassembly. Seeing fluid there means the packing or O-ring needs attention and replacement or repacking to stop the leak. The other locations wouldn’t provide a direct, easily observable indicator of stem packing leakage, so this side-of-valve placement is the practical choice.