Breaking News
Comments
Michael Dunn
User Rank
Manager
Toilet
Michael Dunn   5/29/2014 1:21:24 PM
NO RATINGS
Now if I could just figure out why one (and only one) of my toilets "sucks out" after flushing until there's an air gap in the bowl...

 

Crusty1
User Rank
CEO
Re: Toilet
Crusty1   5/29/2014 1:36:16 PM
NO RATINGS
Your problem is there should be an air bleed, if one toilet outflow is above another. Is there a breather pipe above the sewer pipe, it helps to stop the ball of water sucking.

Michael Dunn
User Rank
Manager
Re: Toilet
Michael Dunn   5/29/2014 1:54:45 PM
NO RATINGS
I've thought it might be related to venting, but could never figure out exactly what the problem was (or as Glen might say, the equivalent circuit). There are two vents on the roof...

Can you explain exactly where the breather needs to be, and what is causing the suction?

This toilet is on the main floor – there's one above and one below, which don't have this problem. Also, nothing affects the slow, steady suckout of the afflicted bowl (takes a couple minutes). I can flush other toilets and run other water – no impact on the current sink..., uh, current bowl.

 

zeeglen
User Rank
Blogger
Re: Toilet
zeeglen   5/29/2014 7:08:22 PM
NO RATINGS
@Michael There are two vents on the roof...

Maybe there should be a third vent that never got installed.  Or maybe one is clogged by a bird nest or dead squirrel.

Still remember seeing a schematic for a (Tek?) scope that showed a little cartoon image in the margin beside a BNC connector.  The image was a wash basin on the outside of a small shack.  The draftsperson had a sense of humour, the connector was labelled "external sync".

Crusty1
User Rank
CEO
Re: Toilet
Crusty1   5/30/2014 3:08:09 AM
NO RATINGS
It's an interesting problem especially if the upstream and down stream bowls do not cause the problem bowl to suck or rise and fall.

I do not sure there is the equivalent of a syphon, in an electronic circuit? I am sure there is someone out there that can say there is.

I had this problem once on a house I refurbished, turned out that the bowl was the problem the geometry of the the P or S outflow from the bowl was that the outfall side was slightly lower than the standing water height in the bowl should be, and thus it sucked.

If you have a cheap e-bay USB waterproof camera "enderscope" you might be able to see what the inside of the pipe is like on the affected bowl and outflow.

 

David Ashton
User Rank
Blogger
Re: Toilet
David Ashton   5/30/2014 4:36:03 AM
NO RATINGS
Hi Crusty.....  "I do not sure there is the equivalent of a syphon, in an electronic circuit? I am sure there is someone out there that can say there is."

Nice challenge!!  How about a diac or a thyristor in a Capacitor-Discharge Ignirion or photoflash circuit?  The cap represents the bucket of water, which will not be drained unitl the diac reaches its breakdown voltage (ie the level of the water is high enough, like an automatic toilet flush) or the thyristor is triggered (ie the syphon is primed) ??

Crusty1
User Rank
CEO
Re: Toilet
Crusty1   5/30/2014 5:21:53 AM
NO RATINGS
Hi David: Near but not quite I think.

The syphon automatically stops when both input and output are the same level in height, if we consider an S bend syphon, so to say.

I think we have to add the electrical equavilant of barometric pressure on both sides of the syphon in our wish to show this plumbing as a circuit.

Do you think Max might take up the challange and write an electronics stater manual for plubmbers?

Did you see Jacks new FPGA board on Kickstarter, I like it a lot.

zeeglen
User Rank
Blogger
Syphon
zeeglen   5/30/2014 3:07:30 PM
NO RATINGS
@David or the thyristor is triggered (ie the syphon is primed) ??

Good analogy, and if you include a resistor and discharged capacitor as the thyristor load, the charged capacitor will discharge into the other capacitor. When the levels (voltage) equalizes the current will stop flowing, just like a real syphon.

Michael Dunn
User Rank
Manager
Solderless breadboard
Michael Dunn   5/29/2014 1:24:18 PM
NO RATINGS
I have no issues soldering pipe (though yeah, it's gotta be dry)! But I now use other methods whenever feasible. Compression fittings are great. And there's a newish system called Sharkbite (I think) where fittings just press on. Sweet!

 

tmiller11147
User Rank
Rookie
Plumbing problem
tmiller11147   5/30/2014 2:40:05 PM
NO RATINGS
Sure hate to tell you this but that pin hole may be due to acidic water. You might get it tested to see if the pH is below 7.2 or so. The acid etches away the inside of copper pipe. If that is so, I would expect you will have more leaks in the future.

 

zeeglen
User Rank
Blogger
Re: Plumbing problem
zeeglen   5/30/2014 3:11:06 PM
NO RATINGS
@tmiller that pin hole may be due to acidic water

Thanks for the tip, but seeing as we are on the city water supply not much can be done unless I install a rain barrel :^}.

The home improvement center plumber said it was probably due to the original installer not cleaning the flux off properly.

jimfordbroadcom
User Rank
CEO
Plumbing inductor...
jimfordbroadcom   5/30/2014 3:19:39 PM
NO RATINGS
To say nothing of the mechanical/plumbing equivalent of an inductor, the mass of the water in the pipe.  I used to run into that when turning off my lawn sprinklers; the sudden drop in current (water flow) in the pipes caused a thunk analogous to ringing in an inductor when a switch is opened.  Since having put in automatic valves I don't pay much attention to how much of a thunk happens anymore.

A few years ago we started getting pinhole leaks more and more often at our house, so we had the guys come in and replace the old copper pipes with PEX, crosslinked polyethylene.  It was supposed to be quieter than copper but was anything but.  The plumbers installed a ~1 gallon tank by the water heater, and I assume it is supposed to act like a capacitor to resonate out the inductance (mass) of the water in the pipes.

Well, it didn't help, and after several weeks of back and forth, the manufacturer of the shower valves, Moen, replaced them and the noise went away.  Moen claimed that the installation of the valves was faulty.  We never did find out what caused all the noise, but it's gone, and that was the main outcome we were looking for.

Glen, I've passed the link to your story on to one of the techs here.  Hopefully he can learn some good electronics from it.  Thanks!

przem
User Rank
Manager
draining the pipes
przem   5/30/2014 5:29:46 PM
NO RATINGS
You are right that the water above your work site is draining slowly. A simple solution to that is to open the faucets at the top of the pipe stack feeding the place you are at. Since you normally don't know how the pipes are run, just open up all the faucets in the house, after of course closing the main feed.

zeeglen
User Rank
Blogger
Re: draining the pipes
zeeglen   5/30/2014 6:51:02 PM
NO RATINGS
@przem  open up all the faucets in the house,

That works if there is a faucet at a lower elevation than the leak.  In my case the leak was at a lower elevation than all the faucets.

przem
User Rank
Manager
Re: draining the pipes
przem   5/30/2014 9:45:41 PM
NO RATINGS
The idea here is to let the air in at the TOP of the pipe stack, because otherwise the low pressure prevents the water from flowing out at the low end. It's the same idea as the nipple on the other end of  your gas can---http://www.pslc.ws/macrog/images/gascan.jpg ; you open it at the top of the can to help the flow out of the bottom.

salbayeng
User Rank
Rookie
Soldering pinholes
salbayeng   5/31/2014 2:16:22 AM
NO RATINGS
I've had two of these pinholes , the first was when I did some bathroom renovations and put a nail through the copper pipe, it didn't leak for a couple of months until the nail rusted away.

But I wasn't going to pull off the tiles from the bathroom having spent months gettiing it right !, so I went it through the outside wall by pulling off the cladding, fortunately it was a 1/2" pipe and 2' above the lowest tap, so no "capacitor" problems, but extremely awkward access for the soldering.

The second time , we could hear the hissing noise in the pipes, and the meter was slowly turning but nothing was wet, took ages to find the leak, it was where the main copper feed pipe (1" diameter) went under the concrete slab the house was built on.  A tree root had wedged itself in there, and stretched a 4" length of pipe to 5" , and a pinhole had formed due to the stretching.  Access was a nightmare, I needed to cut a section of footpath to get anywhere close, then cut up the tree root (about 3" in diameter) using successive attempts with a 1" drill bit. Finally I could get to the leak, but it was close to being the lowest point, So I had all the aforementioned problems with water pooling / syphoning / steam. I used a MAPP blowtorch, and I could get enough heat in to get solder to stick everywhere but the hole (due to steam exiting hole) took me a while to figure out a solution: make myself a brass or copper tapered plug, and wedge it into the hole, then solder over the whole lot. Once the plug seals the leak, it stops all the syphoning and glugging and the steam now pushes the water away, and the soldering operation is straightforward, and it's a lot stronger as it's a capillary situation rather than a gap spanning situation.

So here's my tips
  • Use a MAPP gas cylinder (twice as much heat as propane)
  • Make a wedge shaped plug of copper/brass

To suck water out of inaccessible places, you can use an ejector (also an easy way to prime a pump!)  You can buy them at aquarium shops or just use a vacuum source from a pick n place machine (from Ebay) they work with water just as well as compressed air.

salbayeng
User Rank
Rookie
TIP: re working on irrigation plumbing
salbayeng   5/31/2014 2:48:35 AM
NO RATINGS
Here's another useful tip for repairing irrigation plumbing, this is typically in PVC and can get brittle after a decade, and tends to get broken while you are replacing buried valves etc.  In this case the same tree root as in my earlier problem had also cracked a PVC pipe about 3ft away! And while trying to dig it up, I accidentally cut through the PVC pipe.  The problem is basically the grass roots and tree roots make a tough mat to dig through and the pipes are only 8-18" below the surface. And my soil is sandy, so it keeps falling into the hole, and water leaking from the pipe files the hole up, and the valve wiring is the same color and size as the grass roots!. 

OK here's the tip, you make up all the plumbing using standard 1/2" click-lock garden hose bits, and attach to the end of a garden hose
  • obtain a jet nozzle (or a 1/8" hole in a blanking piece works)
  • obtain an ejector (the aquarium/pond type works well)
  • get some 1" or bigger hose to attach to the outlet of the ejector (it won't push more than about 3' unless it's down hill
  • get a Y joiner with a valve on each leg
  • And plug it all together

So you basically use the nozzle to "saw" through the soil while the ejector sucks out the mud (make a sump in one corner of your hole, put the ejector in there, and just wash the dirt into the sump)  and moves it about 4' away.

So you basically wash all the dirt off the grass / tree roots in-situ , then cut the roots with scissors or pruning shears (or just tear off by hand). You can make quite a large hole very quickly without damaging buried pipes or wiring , and you can make access cavities underneath valves or plumbing that would be impossible with a spade. You do need to scoop out  gravel by hand , (and if the ejector sucks up a rock, just block the outlet with your hand to backflush) 

zeeglen
User Rank
Blogger
Re: TIP: re working on irrigation plumbing
zeeglen   5/31/2014 10:42:46 AM
NO RATINGS
@salbayeng So you basically use the nozzle to "saw" through the soil while the ejector sucks out the mud

Great idea.  Had to look up 'ejector' on Wikipedia.  Will remember this tip when I get around to repairing the broken lawn sprinkler popup and pipe, last winter some vehicle cut the corner of my lawn and drove over it.

kfield
User Rank
Blogger
DIY Plumbing?
kfield   5/31/2014 2:11:22 PM
NO RATINGS
So how many of you out there do your own plumbing work, and how much do you think I get taken by hiring a plumber rather than doing it myself? I suppose I do save the frustration, but wondering just how much I should be thinking about plunging in (no pun intended)!

przem
User Rank
Manager
Re: DIY Plumbing?
przem   5/31/2014 10:03:23 PM
NO RATINGS
I have a simple $30/hour rule about DIY: I will spend money to  replace or fix something if it would have to pay myself less than $30/hour to do it myself. For instance, I don't change the oil in my car anymore, because after buying the oil/filter and having to schlep the used oil to the city dump, I don't save time or money.

Plumbing tends to be the other way: the plumber charges one hour minimum ($60-80) just for showing up, and you have to be there for the appointment, anyway, plus they tend to leave the cleanup to the customer, so I figure I might as well do the whole thing myself.

Another example is reading the car engine codes. A Chinese Bluetooth OBD-II reader costs less than $20, works with an app on my Android phone, and saves not only the $70 that the shop charges for readout but allows me to independently check the meaning of the trouble code ("No, I don't need to spend $2000 replacing all catalytic converters just because my check engine light came on").

The most important thing is once you learn a skill you are set for life and don't depend on anyone.

salbayeng
User Rank
Rookie
Re: DIY Plumbing?
salbayeng   6/1/2014 2:39:56 AM
NO RATINGS
@PRZEM  ,

I think the same way , and about $30/hr  seems a sensible threshold. 

I mow my own lawn with a ride-on mower ,because it takes me 30 min to get it in and out of shed (even if the gardener drives it) , but I leave all the edge trimming , pruning and weeding to him.

With plumbing sometimes its  half and half, its silly to pay someone $100/ hr to dig holes , so at least you can dig holes/ lift pavers etc so when the plumber arrives his billable time is short. Sometimes after doing all the prep, you find you can fix it yourself. Irrigation systems are a good example of this.

(BTW I'm in Australia) Recently I needed an ultrasound ,  the nearest diagnostic imaging company, about 10kms away, wanted ~$400 and couldn't do it for a month. But a private hospital some 50km's away could do it for free the same day. 

Given that I already had to drive somewhere, the 80km extra round trip distance amounted to 90 mins of my time in order to save $400,  So that's $266/hr , way more than $30/hr

 

salbayeng
User Rank
Rookie
Ejector
salbayeng   6/1/2014 2:56:56 AM
NO RATINGS
The ejector has a variety of names , e.g. venturi, aspirator.

if you search on ebay for " pond suction -cup "  you will find some pictures of e.g. a "mud sucker"  and a "pond mini-vac" 

You can make one yourself by starting with say a 1" plastic tee, and screwing in a reducing bush with a hose adapter and a hose tail (for a nozzle) . I used to make them myself, (then discovered I could buy better ones for less than the $30/hr to make them! )

 

Continuing the electronic analogy theme of the original blog... 

An ejector is very much like a transistor ,  you push a current of fluid into the "base" , this causes it to suck up stuff through the "collector" and eject the sum of both flows out the "emitter"  (a PNP might be easier to visualise) . Homebuilt ones might have a HFe  of 1 to 5 ,  store bought units maybe 10 to 50 

Sheepdoll
User Rank
Blogger
Re: Ejector
Sheepdoll   6/1/2014 3:37:51 AM
NO RATINGS
I am having trouble visualizing how all this connects together.  We have a pond which could probably use a vacuum.

I also use something like a hydraulic monitor for cutting under the sidewalk. (a plastic nozzle with a taper on it.)

I need to fix some sprinklers, but with the drought here in Northern CA, the adobe soil is like brick.   The monitor would cut it, exept all the water pools in the adobe, and has to be pumped out.

I know about venturis from the rocket group I am president of.  These things work on air or other fluid. (I have a 19th century textbook on the subject.)

What I can not visualize is how the venturi connects to the monitor and can move the silty mud that backs up in the hole.  Where does the Y valve fit in.  Does this connect to the water supply with one leg to the venturi and the other to the monitor?   If the venturi port is sucking in air, what keeps it from being clogged?

 

salbayeng
User Rank
Rookie
Re: Ejector
salbayeng   6/1/2014 5:24:39 AM
NO RATINGS
Hi SheepDoll,

Yep you pretty much have it in your last paragraph. The nozzles I use are orange, and bought from a $1 shop in Buffalo (on one of my visits to the US).

(I've not heard of "hydraulic monitor" before but now we have google! I do recall seeing them used on a History channel show, some sort of gold? mining operation) 

You also need two lengths of 1/2" hose , about 3' long, with the click-lock fittings at each end. (I use PVC tubing instead as it's more flexible) 

So you basically split the water supply into two using the Y piece with the valves, sometimes you need to turn off one or both of nozzle and suction; and have a 3' length of hose for each of the nozzle and ejector.

Ok "adobe" just seems to be dried dirt? domestic water pressure should cut that OK (without resorting to a pressure cleaner) (we have "silcrete" in the western parts of Australia , it's like asphalt!) 

You need to make a deep corner in your excavation, this is the sump, the suction unit shoud be contrived to be 1/2" above the bottom, so it doesnt suck onto the bottom of the sump,  a small piece of wire netting (1/2" holes or smaller) (like used in aviaries) can be used to form a basket around the bottom , this also catches big chunks that might cause blockages. You would normally leave the suction unit in the one place.

If it's a flat pond or has many low  spots you might need to move the suction unit around a bit. I've usually emptied ponds down to ~ 1-2" with the pond pump first. The wire mesh basket prevents damage to any fish you might accidentally try to suck up.

Avoid hydrostatic issues by discharging the water a long way from the pond and waiting several days after heavy rain. 

The venturi is fine sucking air, it generally works best sucking half air and half muddy water . You will spend half your time cutting and the other half chasing the mud into the sump. 

A secondary issue is what to do with the pile of mud and muddy water at the exit hose , if diverted to a shallow tub , you can then recover about half of the volume of dirt. Or maybe a large piece of shade cloth? or weed mat? 

 

kfield
User Rank
Blogger
Re: DIY Plumbing?
kfield   6/3/2014 6:58:10 PM
NO RATINGS
@PRZEM Do you run the risk of becoming the family "go-to" guy/girl (or help desk) when you learn a special skill? Or is that potentially a good thing? I had a brother-in-law who would come with my sister to visit and take care of all of the handyman type things while he was supposedly "on vacation." Tightening loose latches, repairing our screen door, and other kinds of marvelous things. 

kfield
User Rank
Blogger
DIY Plumbing?
kfield   5/31/2014 2:11:30 PM
NO RATINGS
So how many of you out there do your own plumbing work, and how much do you think I get taken by hiring a plumber rather than doing it myself? I suppose I do save the frustration, but wondering just how much I should be thinking about plunging in (no pun intended)!

zeeglen
User Rank
Blogger
Re: DIY Plumbing?
zeeglen   5/31/2014 6:11:43 PM
NO RATINGS
I think most eng types would carefully analyze the situation before paying for outside help.  This applies anytime something is broken (cars, air conditioning), not just plumbing.  But one also has to consider one's experience and capabilities in unfamiliar endeavours, aka 'learning experiences'.

One good learning experience for me was replacing a burnt-out relay in the outdoor air conditioner unit.  The relay was a no-brainer, but I learned something useful about botany - all the weeds growing around the A/C were poison oak.  I spent my honeymoon vacation with a huge rash on arms and legs.  I now know what poison oak looks like...

It's always good practice to ask for advice from those experts who have no pecuniary interest in your problem.  Like the time a puddle developed on the floor around my indoor A/C system - the A/C guy (who kept the A/C working for my wife's restaurant) advised that maybe the drip pan drain was clogged.  He was right - cutting open the wall and shoving a wire down the drain tube (which led to the bathtub drain across the wall) solved the problem.  Would have cost a few hundred to bring in the experts.

kfield
User Rank
Blogger
Re: DIY Plumbing?
kfield   6/3/2014 6:55:19 PM
NO RATINGS
@zeeglen thanks for your advice - the poison ivy story was a great cautionary tale!

Bert22306
User Rank
CEO
Re: DIY Plumbing?
Bert22306   5/31/2014 6:45:53 PM
NO RATINGS
Just reading the various posts gave me a migraine. Yes, certainly, I can usually determine what the problem is, but I also know not to tackle jobs that would take me days of agony to do. And then obsess over, and wonder if I shouldn't have done it better. For that sort of job, call the plumber! He is likely to have seen the same problem multiple times, to have figured out all the dead end approaches to fixing it, and he is likely to be in and out in a matter of hours at worst.

Certainly, attempting to solder a pipe when water is still in there is something any competent plumber has long since learned not to do. For those situations in which the water is at a low point, the plumber will most likely cut the pipe, siphon the remaining water out, or at least siphon enough of the water out (or suck it up with a turkey baster), and then solder in a new section of pipe. With the right tools and experience, the plumber can do this in no time, where I'd be sweating it out for endless hours.

I suppose it all depends on your personality. Some people don't mind punishing themselves, some mind it a lot!

zeeglen
User Rank
Blogger
Re: DIY Plumbing?
zeeglen   6/18/2014 9:37:21 PM
NO RATINGS
@Bert (or suck it up with a turkey baster)

Sorry I didn't see this sooner.  Brilliant idea!  Will remember this for the next time.

Stargzer
User Rank
CEO
Sounds like a job for Marine-Tex
Stargzer   6/2/2014 1:38:06 PM
NO RATINGS
Marine-Tex is an epoxy putty that has myriad uses around boats.  A guy I used to work for that owned a 30' Egg Harbor said he'd know someone that used it to fix a crack in an intake manifold.  The engine heat helped it to set quicker!

If forced into the hole I'd expect it to set up and remain in place. 

 

salbayeng
User Rank
Rookie
Re: Sounds like a job for Marine-Tex
salbayeng   6/3/2014 2:11:44 AM
NO RATINGS
That jogged my memory,  while working on refrigeration systems , we had this epoxy stick http://www.laco.com/repair-sealants/heat-seal-stik/  , it looked like a big green crayon, you cleaned up around the leak, then heated the pipe (150C??), and just rubbed the "crayon" on the leak, I used it once when there was no access for soldering and it's pretty strong as the refrig system could get to > 200Psi.

Another product I found in my old refrig kit is "RedEpoxy" , this is a two part epoxy you mix up seperately, then apply it to a warmed section of pipe, then apply heat till it goes gold, takes a minute, and it's good for 300psi. http://www.highsidechem.com/redepoxy.html 

Both of the above can be obtained from a HVAC shop and are specifically designed for high pressure leak fixes. You also have a range of kneadable epoxies similar to marine-tex  like this one http://www.laco.com/repair-sealants/epoxy-stik-/  personally I've had mixed results with kneaded epoxies, they tend to be porous.

 

Bert22306
User Rank
CEO
"Ejector" didn't sound familiar
Bert22306   6/2/2014 4:32:50 PM
NO RATINGS
The term "ejector" didn't sound familiar, however back in remote storage, I dredged up the term I am familar with: eductor.

http://en.wikipedia.org/wiki/Water_eductor

Also, to make an analogy between the eductor and a transistor, you'd have to go to the (relatively uncommon) common base configuration. In this configuration, the "bias" voltage would be the water pressure being fed by the water supply to one of the legs of the Y connection (aka transistor's collector). The other leg of the Y connection would be the base. The bottom of the Y, which spits our the supply water plus whatever the pump sucks up, is the emitter.

So what happens is that as water pressure is applied to the "collector" of this pump, some "base" current will flow (into the transistor, current from ground through the base), and the sum of collector and base current flows out the emitter. But notice, no voltage gain here, just as there isn't any pressure gain in an eductor.

A regular water faucet is probably a more typical analogy to a transistor, say in emitter follower (common collector) configuration. Water pressure is applied at the "collector," and then a relatively small effort at the faucet's tap (base) will cause a large change in "emitter" water flow. The pressure of the water out of the faucet won't exceed the pressure of the water feeding the faucet, just as in an emitter follower amp, but you'll get large gains between effort applied at the tap and the amount of water flow and pressure out of the faucet.

Eductors can be super efficient pumps, e.g. for de-flooding, if you feed them, say, with typical firemain pressures.



Flash Poll
Top Comments of the Week
Like Us on Facebook
EE Times on Twitter
EE Times Twitter Feed

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
EE Life
Frankenstein's Fix, Teardowns, Sideshows, Design Contests, Reader Content & More
Max Maxfield

The Best of the Best Videos on YouTube
Max Maxfield
2 comments
A couple of days ago, my chum Paul was visiting me in my office. He'd wandered over from his cubicle in the next bay to take a brief coffee break. This week, Paul had been admiring the ...

Jolt Judges and Andrew Binstock

Jolt Awards: The Best Books
Jolt Judges and Andrew Binstock
1 Comment
As we do every year, Dr. Dobb's recognizes the best books of the last 12 months via the Jolt Awards -- our cycle of product awards given out every two months in each of six categories. No ...

Engineering Investigations

Air Conditioner Falls From Window, Still Works
Engineering Investigations
2 comments
It's autumn in New England. The leaves are turning to red, orange, and gold, my roses are in their second bloom, and it's time to remove the air conditioner from the window. On September ...

David Blaza

The Other Tesla
David Blaza
5 comments
I find myself going to Kickstarter and Indiegogo on a regular basis these days because they have become real innovation marketplaces. As far as I'm concerned, this is where a lot of cool ...