Stored-Energy Surprises: Pneumatics and Springs

Mechanical and pneumatic stored energy injures people during routine pit work because it's invisible. A cylinder that fires when you bump a button, or a climber spring that releases when you remove a pin, moves faster than you can pull your hand back.

Pneumatic mistakes:

• Mistake - Working on a charged system. A robot can hold stored air even when 'off.' Touching a fitting or solenoid can fire a cylinder. Fix: before any pneumatic work, open the manual vent plug (FRC rules require an easily accessible manual vent valve that releases all system pressure without tools) and confirm BOTH the storage and working pressure gauges read 0 psi. Inspectors verify that pressure fully vents.
• Mistake - Wrong relief valve or regulator setting (R811 / R808). The compressor relief valve must be set to release at 125 psi (R811), and the working-pressure regulator must be set to 60 psi or less (R808), providing all working pressure. Fix: install/verify the relief valve and regulator before inspection.
• Mistake - Assuming 'off' means 'safe.' It doesn't. Fix: make 'vent to zero' part of your LOTO procedure every time.

Spring and elastic mistakes:

• Mistake - Removing a pin from a loaded climber or intake. Springs and surgical tubing store energy, and R608 governs allowable non-battery energy-storage sources. Pulling a retaining pin can snap a mechanism shut on a hand. Fix: relieve the spring/tubing first - back off tension, support the mechanism, or use a controlled-release tool. Never put fingers in the path of a loaded element.
• Mistake - Raised arm with no support. A raised arm or elevator held only by a motor will drop when power is cut. Fix: lower it or block it before working under it (part of dissipating stored energy in LOTO).

Diagnostic habit: before reaching into any subsystem, ask 'what's still holding energy here?' and answer for all three forms - air, springs/elastic, and gravity-held masses. Vent it, relieve it, or block it, then try to move it by hand to verify it's safe. The teams that get hurt are the ones who skip the 'verify zero energy' step because the fix 'will only take a second.'