What's the deal with plumbing

Apr 28, 2006 20 Replies

So this morning, as someone decided that it would be a good idea to run the dishwasher at the same time I wanted to take a shower, the following thought hit me:



What's the deal with plumbing? It's like a circuit board with a power supply that has no line or load regulation, no filter capacitors, traces too small to handle the necessary current, and no bypass capacitors.



It's not quite as bad as you're saying... back at the pumping station, there's certainly regulation, and there is a tiny amount of filtering (those water hammer prevention tubes). I'd say it'd more like a board that has long leads (inductance) going back to a reasonably good, regulated power supply... but no point-of-load regulation (other than by you turning valves!). As for traces too small to handle the current... this is often a historical problem, where systems designed for small communities end up being overloaded when the population explodes, or when the pipes become gummed up throughout your house or start springing leaks. (There are cities where for every gallon put into the system, a shocking small fraction comes out -- like 1/2! -- the rest being lost to leakage.)

I believe there are plenty of fancy devices for plumbing to keep everything kopesetic under varying conditions, but of course these devices cost money, and in some cases are difficult to implement without control electronics as well (and historically it seems that plumbers and electricians don't always talk to each other than much!). It does seem that developed countries outside the U.S. have slightly more sophisticated plumbing... some have incoming "high pressure" lines that are used for things like washing machines, dishwashers, sprinklers, etc., but then split off a regulated lower pressure line for faucets; you have to be careful to buy the right faucet in stores, as many can't be used directly off the high pressure line. Someone from overseas can clue me in more here...

You can buy regulators (proportional control valves).

Keith

Hello Joel,

It's more on a local level in most cases. Lines into houses are puny in the US, 1/2" or 3/4". So what Carl is seeing is that the advent of modern appliances such as dishwashers did not come with a subsequent upsizing of the pipes ("traces"). In the old days you poured water into a kettle, heated it up and dumped it into a bathtub. Dishes were washed in the sink, often the same location where that kettle was being filled.

Other countries do have better plumbing. I have lived in Europe and was used to nary any pressure drops because the main line was 1" or more. We could use toilets without tanks, something that is next to impossible in the average US residence. This also meant no spills. We had a tank quietly break a couple years ago while nobody was in the house. What a mess.

After moving to the US I was pretty amazed about the yard sprinkler systems. Until the day when I took a shower and the first backyard circuit came on. Then I looked at the tiny main line coming in and was surprised. Bought a pressure gauge and voila: A drop from 50psi+ to under 20psi when the sprinklers came on. Bought some more plumbing, a bigger timer and split the circuit so it's better now.

Regards, Joerg

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And wires that self-oscillate.

John

Yes, I was thinking more of the plumbing in my house than the city water distribution system.

What do you do if the pressure is already too low?

Richard Henry wrote: > > You can buy regulators (proportional control valves). >

When I called the city for that problem, they came out and measure the pressure at the street at 100 psi. They measured it in the backyard and found 85 psi and they wondered why. HEY GUYS, the house is up a hill... The pressure was even lower on the second floor. duh. Later the street regulator went bad and started oscillating. Pipes rattling is not a happy sound. They were reluctant to fix that as well though they finally sorted it out.

GG

You fork out for a booster pump. Turn your shower into a pressure washer.

Best regards, Spehro Pefhany

"it\'s the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com

Hello Carl,

Upgrading that would be expensive. Also, I have heard that the base charge from the water works is higher if you want a larger size main into the house. Never understood why though.

Regards, Joerg

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Part of it is the meter size.

...Jim Thompson

| James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC\'s and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | | http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.

Maybe they figure the cost of the water mains is determined by the potential peak usage.

Best regards, Spehro Pefhany

"it\'s the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com

Or to the watering of lawns. ;-)

Cheers! Rich

It requires a bigger, more expensive meter.

Where I live, you can get a big pipe and meter at the 3/4" cost if the house has a fire sprinkler system.

Proportional control vlave pressure regulator. A proportional control valve tries to keep the _temperature_ constant by keeping the ratio (pressure) of hot and cold water constant. If someone flushes the toilet when you're in the shower it'll compensate for the loss of cold water by also cutting back the hot.

Keith

Hello Richard,

Why would that meter be more expensive? IMHO it can only be because of production quantities. In that case they could be brought in from Europe where meters usually have very large pipe connections. They would just need to be re-geared away from liters and be equipped with face plates in English. Or soon probably English and Spanish...

Regards, Joerg

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" (There are cities where for every gallon put into the system, a shocking small fraction comes out -- like 1/2! -- the rest being lost to leakage.) "

Oh, so you've been to Montreal? Don't forget to admire our potholes, and try to take a picture of a blue collar "worker" actually working, you can get money for those.

Hi

I work for a pump producer

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and we have lots of control features. Right now I'm working on a high-efficiency domestic

50W pump with low as low as 6W consumption at most times including self learning routines to reduce noise effects from termostats
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Just mine 2 cents worth

Regards

Klaus

Why not have a valve that put the yard sprinkler on hold anytime a shower is sensed ..? Could be as simple as a ir-detector in the shower -> 555 -> valve magnet.

I would like an pump that manages 90 C°, is dead silent, pumps something like .5 liters/min, pipe attachments for both in & out flows, and use 12V DC.

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