Grumble wrote: ↑Fri Sep 17, 2021 5:38 am
At my work we buy pipe work and fittings in imperial units, but our oldest kit comes from the 60’s and we had to maintain compatibility.
I like to troll fans of imperial units by telling them I only work in real money, and ask them to convert miles to km.
You probably buy the fittings and pipe in imperial for diameter, but the pipe lengths in metric. Although it may be that the longest individual pipe length is 12.2 m (ie, 40 ft!)
In the oil and gas industry we commonly measure gas flowrates in millions of standard cubic feet per day (which is actually a measure of number of molecules, but based on feet) but liquids are in m3/h and more recent facilities now measure in standard cubic metres per day. Drilling wells is almost entirely based on US imperial units (well bore diameters in inches, drilling mud density in pounds per gallon (US gallon
), etc) but even they now measure drilling depth in metres.
Pressure used to be measured in pounds per square inch, but is more usually in kiloPascals now. But a lot of the design correlations still use the old psi calculations, so sometimes require you to convert kPa into psi for a calculation step, and then convert back again!
Pipe diameters go up in multiples of 50 mm; it used to be in multiples of 2" but thankfully *most* pipe suppliers have stopped selling, eg, 24" pipe at 610 mm diameter and now just sell pipe at 600 mm diameter.
Sometimes you still have to specify separator body diameters in multiples of 4" (101.6 mm) diameter (rather than multiples of 100 mm) if the fabrication yard which makes the ends is still using older machinery which is still based on the Imperial system, but thankfully most of these are converting, too.
So an industry which ~20 years was almost entirely using imperial measurement is moving slowly towards SI units. At least it keeps graduate engineers on their toes, having to convert from one set of units to another.
"My interest is in the future, because I'm going to spend the rest of my life there"