Fire extinguisher
From DDL Wiki
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Automated fire extinguisher | Automated fire extinguisher | ||
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| Bracket falls off wall | | Bracket falls off wall | ||
| Compromises structural integrity of the canister and triggering mechanism | | Compromises structural integrity of the canister and triggering mechanism | ||
| - | | 5 || Bracket not screwed securely to wall || 5 || Test mounting bracket on different types of walls || 3 || 75 || Treat motor axis to add strength || | + | | 5 || Bracket not screwed securely to wall || 5 || Test mounting bracket on different types of walls || 3 || 75 || Treat motor axis to add strength || Design Engineers || - || 5 || 5 || 3 || 75 |
|- align="left" valign="top" | |- align="left" valign="top" | ||
| - | | | + | | Pressure Gauge || May not display proper reading. || Empty extinguisher could read as full. || 10 || Pressure from canister not correctly transmitted to gauge. || 2 || Test gauges by slowly discharging canister || 3 || 50 || Increase space around the pressure gauge in order to ensure that the gauge correctly reads the pressure in the canister|| Design Engineers || - || 10 || 2 || 3 || 50 |
|- align="left" valign="top" | |- align="left" valign="top" | ||
Revision as of 21:38, 23 September 2007
Automated fire extinguisher
| Item & Function | Failure Mode | Effects of Failure | S | Causes of Failure | O | Design Controls | D | RPN | Recmd Actions | Responsibility & Deadline | Actions Taken | S* | O* | D* | RPN* | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mounting Bracket | Extinguisher falls off bracket | Compromises structural integrity of the canister and triggering mechanism. | 8 | Canister not secured to bracket | 5 | Secure canister to bracket | 5 | 125 | Add strap to make sure canister is secured to bracket | Design Engineers | - | 5 | 5 | 5 | 125 | |
| Bracket falls off wall | Compromises structural integrity of the canister and triggering mechanism | 5 | Bracket not screwed securely to wall | 5 | Test mounting bracket on different types of walls | 3 | 75 | Treat motor axis to add strength | Design Engineers | - | 5 | 5 | 3 | 75 | ||
| Pressure Gauge | May not display proper reading. | Empty extinguisher could read as full. | 10 | Pressure from canister not correctly transmitted to gauge. | 2 | Test gauges by slowly discharging canister | 3 | 50 | Increase space around the pressure gauge in order to ensure that the gauge correctly reads the pressure in the canister | Design Engineers | - | 10 | 2 | 3 | 50 | |
| Helical gear | Mechanical Failures: Shearing. Thermal. Wearing. Plastic deformation to out of spec | Under complete mechanical failure, gear train will not be connected to the motor. Under partial failure, will have possible slippage which will result in inefficient operation and noise | 7 | Heat from motor. Vibrations. Forces from gear train. | 4 | Drive gear at high rpm and/or under intense working conditions | 3 | 84 | Thicker injection mold to make gear larger. Use stronger plastic. | Injection molder(s) prior to installation | - | 7 | 2 | 3 | 42 | |
Shredding cutoff time-delay
| Electrical failures: Short circuited | Product ceases to function reliably. Shredding no longer possible. | 8 | Intense heat and/or vibrations loosen connections, resulting in intermittent operation | 4 | Run under extreme working conditions | 3 | 96 | Add solder to strengthen connections. Add dampening to decrease effect of vibrations | Switch manufacturer prior to purchase | - | 8 | 3 | 3 | 72 | |
| Mechanical Failures: Creep. Fatigue. Deformation. Shear. | 8 | Flat metal spring fatigues leading to fracture. Thermal deformation from heat generation. Plastic deformation from shredding unapproved items | 4 | Compress and expand spring repeatedly and under extreme conditions | 3 | 96 | Treat metal to strengthen. Increase thickness of spring. | Switch manufacturer prior to purchase | - | 8 | 2 | 3 | 48 | |||
| Helical Blade | Mechanical Failures: Shearing. Fatigue. Thermal. Wearing. | Fracture of blade will result in inefficient, but continued, function. Bending of blade can result in wear against other blades, which can also result in a chain reaction leading to complete failure. | 7 | Bending and shearing can result from shredding unapproved items. Fracture and malfunctions can also result from malfunctions of other components such as the main shaft or gears. | 4 | Shred unapproved items. Work at high rpm. Shred lots of paper and/or credit cards | 5 | 140 | Thicker blades for strength. Smaller opening so unapproved items are harder to fit. | Blade stamping department | - | 7 | 2 | 5 | 70 |
