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As a busy engineer, I would say you did your due diligence. There are always more variables than we are given time to consider. The higher the risk of failure/injury, the more time we spend on it, but there are limits. I often try to have another engineer or manager look at my work so there is another set of eyes on it. Also, taking time to test new tools/...


3

The normative reference for the design of wall boxes for electrical work in the US is NEMA OS-1 for metal boxes and NEMA OS-2 for nonmetallic boxes. This, in turn limits the size that components to go into these boxes (including outlets) may be. If you don't want to buy the standard, you can find a good bit of information from it posted from various ...


3

Requirement and Specification are standard English words. They don't mean anything different from the dictionary definitions. A requirement is "something you need, or something you must have." A specification is "how to do something" or "how to make something."


2

For car exidents there is a meassure, which is called Head Injury Criterion. It is a measure to estimate the possibility of an head injury during a car accident. The HIC for the time interval $t_1,t_2$ is given by $$HIC_{t_1,t_2} = (t_2-t_1)^{-1.5}\int_{t_1}^{t_2}a(t)dt.$$ The final HIC is given by the maximum value of the previuos expression, which can ...


2

AISC's magazine, Modern Steel Construction periodically publishes a guide to specifying grades of steel to help engineers stay aware of developments in the market. Their latest edition, from this February mentions A1085, but still suggests A500 Grade C as the standard. They recommend checking that A1085 is available and affordable in your area - it sounds ...


2

Set maximum yield stress of 70 ksi (useful for seismic applications, though I am not well versed in this area) If I have no need to restrict the maximum yield strength of the material and I have no fatigue concerns, is there any benefit to specifying the newer A1085 tube steel material over the existing A500 specification? For practicing engineers in non- or ...


1

TL;DR: (if I really had to) I would use "design specification" as a superset of "requirements" My experience is that: Requirement: tends to be used more commonly in the design phase of a product, and also imply a "absolute minimum". E.g.: When people are on a drawing board and try to decide what the requirement for a new ...


1

That is a radial bearing, as shown in the section view in the drawing. Pillow blocks are typically radial bearings.


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The OP's second link, gives damping rates albeit in a most confusing way. If you work it out, for example, the first damper has 1.4 in/sec as the damping and references 40 lbf which means that the damper applies 40lbf when a velocity of 1.4 in/sec is applied. In this case: $$C_{example} = \frac{40(lbf)}{1.4 \frac{in}{sec}} = 343(\frac{lbf\cdot sec}{ft})$$ ...


1

I think: These ratings are showing the max speed allowed by the damper. Certainly for a specified load, there's a startup acceleration, and further the manufacturers are assuming the load is applied nowhere near an impulse/delta function. Every system has a resonant frequency, meaning that if the load were applied in a very short pulse (or even a short ...


1

You could do a visual inspection with a pipe camera on the interior. Poorly-brazed copper will have discolorations / flaking due to oxidation (just like the exterior would). You can also just pull one of their brazes and slice it in half to inspect it. This PDF ("Brazing Best Practices: 12 Tips for HVAC Technicians" from Nov. 2014 issue of Welding Journal) ...


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