The Trials and Tribulations of Metering the Washing Machines

The initial idea was to use threaded fittings to interface the flowmeter with the washing machines. Fittings make sense, they are usually secure and won’t leak, provided the threads (A) fit together properly, and (B) are designed to seal. If that fails, there are ways to make poorly fitting threaded connectors seal, usually PTFE thread tape or anaerobic sealants.

Brass fitting assembly with residue of Loctite 574 on ¼ in. threads

The Koolance FM-17N flowmeter is threaded for ¼” female BSPP (British Straight thread Pipe Parallel, also known as DIN ISO 228-1). Being familiar with NPT (National Pipe Thread) which is a tapered or conical (self-sealing) design, I didn’t know how BSPP would work, until I tried it. I should have looked at the Koolance fittings more closely before committing to a large parts order of expensive ISO conversion (ISO/NPT) fittings from Swagelok, but I had perhaps too high expectations of Loctite thread sealant. The way ISO straight/BSPP fittings work is that they tighten against a gasket, rather than sealing the threads. The Koolance hose barbs and fittings are designed to work this way, but I didn’t quite understand how this worked, and therefore went with a faulty assumption that I needed to use a thread sealant/threadlocker. Alas, the tolerances of the Koolance fitttings are too wide, and the ISO fittings from Swagelok don’t fit—and of course never seal, even with the assistance of PTFE tape or Loctite 565 thread sealant. Note: the Koolance FM-17N has nominally 1/4 in. ISO straight threads.

Bosch Automotive Handbook: (Krickau & Nöcker, p. 318)

The way Loctite anaerobic sealants/threadlockers work is that they cure in the absence of oxygen, under pressure (such as in the tiny space between threads. A glob of it will stay a slightly sticky glob, but won’t really solidify the same way it will under pressure. This is especially important in applications where it is necessary to wash away the excess that gets squeezed out from between mated surfaces, such as in an engine (use Loctite 574 (the famous Loctite Orange) to put your Porsche case halves together—using RTV will cause your engine to destruct when bits of solidified RTV (silicone) clog the bearing oil passages). With rather large gaps between the threads of the fittings and ends of the flowmeter, the Loctite doesn’t quite cure, and therefore any disturbance causes the adhesive to shear from the surfaces and thus it starts to leak. The idea with Loctite thread lockers is that the shear strength keeps the threads mated.

To add to the slow leaks, the overall length of the assembly is rather long, and with an end rigidly attached to the hose bib or back of the washing machine, any torque causes the acrylic case of the flowmeter to crack—a catastrophic failure in my case. Flooding a dorm basement is not an option.

Ultimately the question is what cycle did the user select, or slightly more generally, what wash temperature did the user select. Without splicing into the water system, it may have been possible (and far cheaper) to use a set of thermocouples or thermistors on the intake hoses, but this relies on there being a substantial change in temperature to indicate what’s going on—and it may not be the case that the cold hose/pipe gets appreciably colder when the water flows through it, and the hot hose may stay warm (above threshold) in two immediate consecutive washes. It would take a bit of tuning to set thresholds, and this approach would have required a positive signal of when the machine is running (cycle start and end), which has been a little more of a challenge, using either an electret microphone to detect vibration or a Hall effect sensor on the power cable. Neither of those are fully foolproof, but fortunately the most positive system for measuring the cycles has been made workable and safe.

Installing the flowmeter in a segment of flexible hose solves the problem of putting stress on the acrylic meter body and cracking the meter, and using the Koolance gasketed BSPP fittings solves the problem of fittings not quite threading together and sealing. The flexible hose effectively prevents transmission of torque to the meter, provided the force is not excessive, and by using a hose clamp and slightly undersized inside-diameter hose, the possibility for leaks is minimized. To further reduce the possibility of leaks, the threads can be sealed with Loctite 574 thread sealant, providing a measure of resistance against the fittings unscrewing and sealing the threads ahead of the gasket integrated into the base of the hose barb.

Koolance hose barb with integrated polymer gasket

FM-17N installed in pressure-rated hose with hose clamps

Quantaproject: The Shake Out

It is fitting to describe the increase in the incidence of obesity and diabetes in the US as an epidemic. For most of human history, the problem has been solving the calorie problem—but now we are suffering on a mass scale from the opposite problem: a surfeit of calories, and ’empty calories’ at that.

Right now, the United States has an enormous public health crisis in the form of a large and rising proportion of the population classified as overweight, obese, and extremely obese. And the trend points to an increasing rate of obesity—and attendant health problems including diabetes type 2.

And it gets worse: the rate of obesity among young people is substantially greater than that of the population as a whole, it is forecast that up to 1/3 of today’s teenagers are at risk for developing diabetes type 2, and may lose 1/3 to 1 year of predicted gains in life expectancy, and a greater number of life-quality years (a year where they cut your toes off isn’t so happy).


How did we get here?

With regard to the need to increase the value of farm products during the Great Depression, subsidy programs were enacted to increase the income of farmers. In 1973, under the direction of Secretary of Agriculture Earl Butz, the paradigm changed to payment to support greater production. Paying to support production of commodity crops has led to (1) a shift towards larger farms, and (2) a decrease in the real cost of sugars, refined grains, cheese, and meat. While this could be considered beneficial in terms of delivering more calories per dollar, it has decreased the quality of the American diet, and undoubtedly contributed to the increase in obesity and diabetes.

Americans now spend less on food than at any time in history, but this decrease in expenditure on food comes at the loss of diet quality. Vegetables, fruit, and non-industrial foods are still rather expensive, and therefore make up less of our diet. The ultimate result of the decrease in food cost is that we eat more: restaurant and recipe portions have both increased in energy value and size, and it’s disturbingly true that we will eat what’s in front of us, see Brian Wansink’s research on this topic:

The US spends billions on agricultural subsidies, which distort the market for agricultural goods, specifically commodity grains which are storable, convertible into products, and useful for animal feed. In 2009, the US spent 4 billion USD on corn subsidies alone, and nearly all of that corn was converted to corn syrup, ethanol for fuel, or used for animal feed. These subsidies can constitute half a farmer’s income, as the fair market price of corn is deflated by the sheer volume produced. On the international scene, these subsidies depress the cost of American grains, injuring farmers abroad and damaging developing nations’ economies.

To use all of this grain and derivatives, new food products and new formulations of familiar ones have been engineered. The Twinkie™ is the standard bearer of packaged food products. Contrary to urban legend, it’s just an engineered cake with a designed shelf life of 25 days. Twinkies are made of things one would expect, like flour, water, butter–and things which are a little surprising, like petrochemicals and processed phosphate rock.

The changes in the American diet may has a metabolic dimension: fructose is metabolized differently than glucose or sucrose (a glucose bound to a fructose molecule), and this may have metabolic effects. See this presentation by Robert Lustig, MD at UCSD for a theory of the impact of high fructose intake. An April 13 NY Times article discusses Lustig’s take on fructose metabolism being a major cause of the increase in diabetes and weight gain. We’re certainly eating a lot more sugar, and a lot more of it is high fructose corn syrup—an average of 42.8 pounds more sugar per year compared to the 1950s, and 42% of it is now HFCS (mostly 55% fructose/45% glucose).

All this sugar is just one component of the greater amount we’re eating, which leads to there being a greater amount of us—and a greater number of us with diabetes type 2.

What it means

All of this adds up to a public health disaster—a loss of longevity, a reversal of the hard-won gains in life expectancy.

The mean life expectancy of current generations (Baby Boom, Gen-X, Gen-Y, Millenials) may actually decrease, relative to predicted increases, as a result of the prevalence of obesity and attendant health effects. The graphic above shows the predicted longevity of a 65-year-old woman. In 2010, she would have a predicted 19.3 more years, in 2050, 21.7 years—but with the effects of increased prevalence of diabetes, and heart disease related to obesity, she could lose 1/3 to 1 year of that predicted gain. This is a terribly disturbing conclusion: gains in life expectancy may slow or potentially reverse, as a result of lifestyle disease—fuelled by a food system designed around profit and special-interest benefits, not the public good.

What to do?

There are plenty of good ideas about what to do. Taking a systems approach, we need to restructure the agriculture subsidies. It’s poor policy to promote growing mountains of corn so vast that new ‘sinks’ have to be developed to use it, it’s unethical to spend taxpayer money to market full-fat cheese at the same time a different department of the same agency is fighting the increase in calorie density of foods and the size of restaurant portions. Restructuring the Department of Agriculture would be a good idea. Changing our diet is a top-down and bottom-up proposition. Access to reasonably priced, healthy foods (fruits, vegetables, legumes, whole grains) is necessary, and many areas this access is not adequate—and in many cases people who can eat well, don’t as a result of preferences. These preferences can be changed as a result of greater exposure and conscious and non-conscious behavior change.