Fire extinguisher
From DDL Wiki
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== FMEA == | == FMEA == | ||
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+ | There are many possible ways for the fire extinguisher to fail. Most failures could leave the extinguisher completely inoperable. Below is a list of failures and the ways in which they affect the overall performance of the product. | ||
Revision as of 22:09, 23 September 2007
Automated fire extinguisher
Parts List
Part # | Part name | QTY | Weight (g) | Function | Material | Manufacturing Process | Image |
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01 | Mounting Bracket | 1 | 32 | Clasps canister, attaches to wall | Plastic | Injection Mold | FEMountingBracket |
02 | Safety Pin | 1 | 3 | Prevents accidental discharge | Pastic | Injection Mold | FESafetyPin |
03 | Canister | 1 | 291.5 | Contains extinguishing agent | Aluminum | Deep Drawn | FECanister |
04 | Spring | 1 | 3 | Holds discharge valve closed | Plastic | Injection Mold | FESpring |
05 | Hose | 1 | 16 | Channels extinguising agent from bottom of canister | Plastic | Extrusion | FEHose |
06 | Valve Pin | 1 | 3 | Blocks flow until displaced | Plastic | Injection Mold | FEValvePin |
07 | Top Assembly Gasket | 1 | >.5 | Creates seal between top assembly and canister | Rubber | Injection Mold | |
08 | Hose-Top Assembly Connector | 1 | 2 | Connects hose to top assembly | Plastic | Injection Mold | |
09 | Valve Pin Top Gasket | 1 | >.5 | Creates a seal on valve | Rubber | Injection Mold | |
10 | Valve Pin Bottom Gasket | 1 | >.5 | Created a seal on valve | Rubber | Injection Mold | |
11 | Diffusing Nozzle | 1 | 2 | Changes diameter of extinguishing agent flow | Plastic | Injection Mold | |
12 | Extinguising Agent | 1 | 1134 | Extinguishes fire | Sodium Bicarbonate | Chemistry Lab | |
13 | Top Assembly | 1 | Weight | Provides handle for gripping and discharging, holds pressure gauge, provides discharge path from canister to diffuser nozzle | Plastic | Injection Mold | |
14 | Pressure Gauge | 1 | Weight | Provides user with information about pressure of canister - "Empty" or "Full" | (Assembly - Platic, Brass, Aluminum) | Varies |
FMEA
There are many possible ways for the fire extinguisher to fail. Most failures could leave the extinguisher completely inoperable. Below is a list of failures and the ways in which they affect the overall performance of the product.
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* | |
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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 | |
Safety Pin | Pin breaks and cannot be removed | If the pin cannot be removed, the extinguisher will not discharge | 10 | Pin is thin, may snap if not pulled out straight | 3 | Test strength of pin | 2 | 50 | Make pin thicker. Use stronger plastic. | Pin Manufacturer | - | 10 | 3 | 2 | 50 | |
Top Assembly
| Top handle breaks | Cannot depress pin to trigger the extinguisher | 10 | Extinguisher falls or is hit by an object | 1 | Test durability of top handle | 5 | 50 | Increase thickness of plastic. Use Stronger Plastic | Design Engineers | - | 10 | 1 | 5 | 50 | |
Bottom Handle breaks | Uncomfortable to hold/use | 3 | Extinguisher falls or is hit by an object | 1 | Test durability of bottom handle | 5 | 15 | Increase thickness of plastic. Use Stronger Plastic | Design Engineers | - | 3 | 1 | 5 | 15
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Valve Pin | Does not seal properly | Could result in slow loss of pressure from the canister, leaving the extinguisher useless | 10 | Rubber gaskets may not fit on the pin correctly resulting in an ineffective seal | 3 | Test seals performance at large range of pressure | 2 | 60 | Find a better way to secure gasket to pin | Design Engineers | - | 10 | 3 | 2 | 60 |
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Canister | Over pressurized | Could result in unexpected rapid decompression, rendering the extinguisher useless and possibly exploding | 10 | Canister is over pressurized | 3 | Test canister to see its maximum pressure | 2 | 60 | Increase safety factor by increasing the maximum pressure rating of the canister | Design Engineers | - | 10 | 3 | 2 | 60 |
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