Talk:Fire extinguisher

From DDL Wiki

We received your report, and we are impressed with your findings. Detailed comments follow:

• Executive summary is good but does not share findings. Also, please check grammar for professionalism.
• Very clear description of the product function, although it is difficult to tell from the picture where the pivot points of the handle are and how motion of the handle translates to open the valve. Also, what kind of seal on the pressure gauge allows movement of the coil spring in response to pressure without allowing the pressure to leak out?
• Good list of customer needs. You may also consider cleanup, safety due to toxicity in addition to pressure, intuitive to figure out quickly, etc.
• The parts list is good. Is the diffusing nozzle a separate piece? How many pieces are in the “top assembly”? You mentioned that the mounting bracket has a strap – is this not included in the parts list?
• Nice overview of DFMA, and good suggestions for DFA.
• Good observations on usability and safety.
• Good observations on LCA and DFE. However, the assumptions on running the three sectors was not clear – what dollar value was run for each? Since the extinguisher does not involve an equal dollar amount from each of these sectors, please explicitly state your assumption of $/unit for each sector.
• The failure mode of the extinguisher falling off of the bracket seems to be your top RPN. We will consider looking into this more extensively to see how much of a problem this is and what we can do to make it more secure while also making sure it is easy to remove for use.
• You mention that the valve spring’s only purpose is to close the valve after the extinguisher has been emptied, but it may also be necessary to close the valve after any use at all – since the pressure inside the tank is no longer fully pressing up on the valve once the valve is opened. Flow of the gas/power will change pressures, and the pressure on the top of the valve is no longer atmospheric.
• You estimate that the force required by the user is around 13 lbs. Is this high? What are your conclusions? Similarly, you estimate that the exit velocity is between 17 and 30 in/s. Is this a good thing or a bad thing?