Safety Info on Four Inch PVC Pipe

I went down to the plumbing supply house today and rounded up some info on 4 inch PVC pipe that I believe folks ought to know.





What I learned is:

1. There are more types of PVC pipe than you may suspect.

2. I know of three schedules: Sched 20, Sched 40, and Sched 80.

3. Sched 20 has 1/8" sidewall on 4 inch pipe. Sched 40 has 1/4" sidewall. Sched 80 has to be ordered(at least at the business I went to) so the sidewall thickness couldn't be checked.

4. There are at least two types of core: foam core and solid core. The foam core is NOT able to withstand pressure. If you buy pipe and see bubbles inside the cut end it is not worth a hill of beans as a container.

5. Pipe that does not have a pressure rating is not suitable to withstand pressure. The pressure rating is found just after the SCHED rating.

6. The plumbing supply house "might" cut the length you want, but SCHED 40 solid core pressure rated PVC pipe only arrives in 20 foot lengths. That means you are looking at 45-50 Dollars in outlay for a container that is about 8-10 inches long. Yikes!

UPDATED: More Info on PVC pipe

7. Great link on PVC pipe pressure ratings: Engineeringtoolbox.com. I note that the pressure rating on this site is noticably lower than the pressure rating of the pipe I bought. This is due to the figures being the industry standard. Individual pipe manufacturers are likely to exceed these numbers and will state so on thir product if they do. If not then go with the industry standard.

8. PVC pipe derates to 20 percent at 140F and long term failure occurs above that. Check the link at Engineeringtoolbox.com.


I think this means PVC pipe should be abandoned and move to one of the other plastic pipe materials unless a non-heat environment can be achieved. According to the charts, PB and PEX perform the best in heat conditions, but have about 40 percent of the strength of PVC. CPVC performs marginally better with heat, but has the same strength properties as PVC.

Thanks to commenters for the additional data and links!

Plate Conditioning Brown Scum Observations

I perform a 34 minute test to further condition the simpleton plate assembly and provide observations as I go.




What I learned.

1. The "scum" forms within 2-4 minutes.

2. The "brown" begins forming shortly afterward and slowly builds concentration throughout the test.

3. The "scum" doesn't seem to progress in volume along with the test.

4. The "scum" leaves a film on a spoon that is inserted into it while the "brown" does not seem to stay on the spoon with the "scum".

5. The "scum" isn't impermeable as larger bubbles trapped in the scum will pop. Tiny bubbles do not seem to pop as readily leading me to think the scum surface tension is higher than just the electrolyte.

6. The scum with trapped bubbles behaves like thick wet soap bubbles. To watch it during electrolysis, it behaves nearly like oil on water when it's disturbed by the fluid motion caused by electrolysis. So it has its own composition which is unlike the water/NaOH mixture.

7. After stoppng electrolysis, the "scum" dissapates rapidly, almost as fast as the trapped bubbles do.

8. The "brown" goes into a kind of suspension and hovers near the surface but not necessarily on the surface.

9. Disturbing the "brown" causes it to slowly sink.

My Theories

1. The "scum" and the "brown" are seperate compounds.

2. The scum seems to be a byproduct of the electrolysis, but to a limited extent.

3. The brown evidently is rust, but requires chemical analysis.

4. The scum may or may not be a distinct compound resulting from the electrolysis. It does seem to dissipate shortly after electrolysis stops.

Results of Running Plate Conditioning at the 75 Amp Setting

I discover what happens when I attempt to condition plates at the 75 Amp Setting of the battery charger. Yet another disaster diverted.

Technical Change to the Smack's Booster Test Cap Assembly

I discovered a leak in the electrode assembly of the Smack's Booster Test Cap and discuss how I fixed it.

Smack's Booster Test Plate Conditioning

I do the blah blah blah while watching my Smack's Booster test plates undergo conditioning. Nice brown scummy water!

Warning about Drain Cleaners in Hydroxy Gas Production

I had a reader warn me about the problems associated with using drain cleaners as an electrolyte in Hydroxy Gas production. Namely, most cleaners have other chemicals in them and can result in the release of Chlorine gas in addition to Hydroxy.

This concerned me greatly so I proceeded to investigate the product I bought for this purpose, Roebic Heavy Duty Crystal Drain Opener.

Here's the film clip for those that are interested.




And here is an email response to my inquiry by Mr David Lawler, Senior Microbiologist and Vice President Product Development.


--------------------------------
Charlie,

Our Heavy Duty Crystal Drain Opener is 100% sodium hydroxide. It is technical grade, not USP grade, meaning there could be trace amounts of impurities, but nothing in high enough levels to be of concern in most applications.

Thank you for choosing ROEBIC products.

David Lawler

ROEBIC LABORATORIES
--------------------------------

I believe this means I can use this particular Drain Cleaner with some assurance that harmful byproducts are minimized. If anyone can show that USP grade Sodium Hydroxide is vital to safety, then please let me know as soon as possible.

Roebic Heavy Duty Crystal Drain Cleaner - Material Safety Data Sheet

Blooper of the Day!

Cut! Cut! Cut! This one's not in the can.

Smack's Booster Initial Test with Unexpected Results

I performed the first test of the Smack's Booster with a Simpleton plate assembly and had a horrific result.



Needless to say, over-amping the electrolyzer has quite a risk to it.

I neglected to mention that the booster was drawing just about 30 Amps when it blew. Additionally, I was looking right at the booster when it popped and the flame was orange. No mistake there.

I plan to test this some more, but not without an enclosure, which I plan on building forthwith.

Lastly, I wonder if the brown scum has something to do with it. Only testing will bear this out. I have an inkling that the scum is ferrous oxide which was liberated from the stainless steel parts. It sure looks like rust water to me at any rate.

Resistance Testing a Smack's Booster with Simpleton Plate Arrangement

I put together several clips as one regarding resistance testing the Simpleton plate arrangement and this is the result.



I determined that the resistance climbs rapidly before leveling off. I should test with a different multimeter to see if it is the result of using a digital one versus an analog one.

Second, it appears that very little NaOH is required, around a half a teaspoon should do it. More doesn't seem to affect the resistance.

Third, the resistance appears to drop 300-400 Ohms when using Sodium Hydroxide versus tap water. To give some indication, my water was tested about a year ago and it had 22 grains of hardness. Yes, I know, like a brick. I was told at the same time that during the summer, the hardness drops way off due to pumping in water from a nearby reservoir, but I have no way of testing that at this time.

Smack's Booster Simpleton Plate Assembly

I put together a short video clip of me assembling a Smack's Booster with what I call a Simpleton Plate Assembly. I intend to test this setup to get some baseline figures and learn more about the design in the process.

Blow Off Testing a Smack's Booster Electrolyzer Container Lid

I wanted to check the safety of the Smack's Booster Electrolyzer Container when it is assembled with plumbers silicone grease as a gas seal inside the top of the container. I'm a bit worried that it may cause the top to seize instead of pop off.

So what I did was devise a test to inject compressed air into the container to see what it does.


Here are the test parts.

• 4" PVC Cleanout Cap Square Head
  
• Metal Tubeless Tire Valve
  

And here is the completed assembly. It also required a 7/16" drill bit in order to get the correct diameter hole for the valve.

After several tests with compressed air, I determined that it takes very little pressure for the top to pop loose, which relieved my concern that it may cause an explosion.



Of course I just had to record the event for posterity.

UPDATE: 30 July 2008

I had a person ask about this setup and it made me realize that the article could be taken out of context. The test was to determine if I could perform experiments using plumber's silicone grease to seal the top without leaking while allowing for a blow off should a backflash occur. The answer is; the plumber's silicone grease can provide a seal, but it seems to be very vulnerable to leakage which will affect productivity and test results. As for the possibility of a backflash, I've had that happen once already and it put a nice dent in the ceiling of my garage.

Constructing a Test Control Panel

After looking at the pile of test gadgets, I decided I had to do something to organize it into something useful. I hit on the idea of a test control panel, but what to make the darn thing out of? How about wood?! Easy enough to work, doesn't have to be pretty, and easy enough to modify as well(provided I have the tools I need to do so).

So off to the store to get yet more parts. I swear this experimenting thing just eats money like it's fillet Mignon.


I started with a simple plan to build an open front/back box with an angled top for better ergonomics. This layout shows the dimensions I used to cut the wood.


Here's the basic frame parts after I cut them from a piece of 1x12x6 and a piece of 2x6 for extra support.


I started building the box from the bottom. I used deck screws 2" long in which case I had to drill pilot holes for each screw to avoid splitting the wood. You could use box nails instead, but it would be a little less sturdy when finished.


Here I'm screwing down the computer power supply which will provide the juice for the control panel. I had to drill 2 holes through the inside corners of the power supply case before screwing it down. There was a screw tab on the opposite side already which saved some hassle. The screws had to be less than 3/4" long to prevent coming out the bottom of the control panel.


That's done. Power Supply is in place.


OOPS! There's a lesson here. DO NOT DRILL HOLES OVER SOMETHING YOU DON"T WANT HOLES IN! The computer power supply experiment nearly came to an abrupt end.


Another view of my little gaff. Not much to see actually.


A stand back and experimental look at the work in progress.


Closeup of the Ammeter, Vacuum/Boost gauge, and Time/Temperature gauge.


Closeup of the meat thermometer.


Closeup of the two multimeters.


Closeup of the power switch.


Closeup of the Ammeter and Reostat jumpers.


Closeup of the dimmer switch as pressed into service as a reostat.


Closeup of the Igniter which was adapted from a gas grill replacement igniter kit.


Closeup of the first set of power jumpers from the ATX power supply.


Closeup of the second set of power jumpers from the ATX power supply.


Closeup view of the front of the control panel. I installed the rail to convert the space into a rat hole to store small items.


View of the left side. I added shed door handles to make it easier to move, not that it's heavy, just a little awkward without the handles.


A view of the back peeking into the rat hole.


And finaly a view of the right side with the port for the power supply.

The Finished Product

Lab Projects Articles

Related: Light Dimmer Switch as a 12 Volt Rheostat: Failure
Next: Converting a Computer ATX Power Supply to a Lab Power Supply, Part 3
Previous: Converting an ATX Power Supply to a Lab Power Supply, Part 2

Converting an ATX Power Supply to a Lab Power Supply, Part 2

Now for the fun part; ripping the power supply apart to begin the process of converting it to a Lab Power Supply.


First I chopped off the connectors to the peripherals using a pair of side cutters.


Then I inspected the motherboard connector and, there is indeed a green wire peeking out of the back.


I lopped off the connector with the side cutters as well.


I organized the wires by color.


I then soldered the green wire to the switch I bought along with a black wire.


I soldered the orange wires together and set that aside.


The "Load circuit" involves soldering a red wire to the 10 Ohm, 10 Watt resister and clamping it to the case as a heat sink. Note I put a rubber grommet around the wire bundle where it goes through the case. This is to prevent cutting through the wire insulation and causing a short.

At this point I had to stop because I couldn't mount the terminals to the power supply. Instead I'll begin construction of the Test Control Panel so I can finish the power supply assembly.

Lab Projects Articles

Related: Converting a Computer ATX Power Supply to a Lab Power Supply, Part 3
Next: Constructing a Test Control Panel
Previous: Making a Lab Power Supply from an ATX Computer Power Supply, Part 1

Making a Lab Power Supply from a Computer ATX Power Supply, Part 1

I found a video on YouTube.com that explains how to alter an ATX power supply for use as a Lab Power Supply. Sounded like an opportunity to use that old computer for something other than a dust magnet!

Search YouTube.com

Conversion Video

Anyway, I found the one that talks about how to perform the "surgery" using a How to convert an ATX Power Supply manual from WikiHow.com.

Part 1 - Removing the power supply

Here's the dust magnet! a Compaq that I used while I was working in Turkey. It has a 250 Watt power supply and it's about to have a heart deplant.


There's the power supply. No switch. Big deal. Yer mine anyway.
I'd hoped for a pic of the specs, but it washed out too bad. Oh well.


There's where the power supply connects to the motherboard, and look! Ferrite cores. Must make a note to remove them as well.


All these red/black/black/yellow connectors have to be disconnected as well.


Another angle of the connectors.


A closeup of the motherboard connector and the peripheral connectors all wadded up in my grubby mitt.


Now to loosen it up using a No. 1 Phillips screw driver and rip it out.


And there's the plunder, one 250 watt power supply, a fan, and a micro switch with two diodes still in the plastic mounting bracket. The ferrite donuts will come out later when I think of them.

Lab Projects Articles

Next: Converting an ATX Power Supply to a Lab Power Supply, Part 2
Previous: Setting Up the WorkBench

Test Electrolyzer Cap Construction

The first Electrolyzer cap is a test unit and I intend for it to have no bells or whistles to start out with, nor any fancy connections.


The obligatory group photo of the parts and some of the tools.

• 3/8" ID clear vinyl tubing
  
• (2) 1/4"-20x1-1/4" 3/16" Allen Stainless Steel Cap Screws
  
• (2) 1/4" ID Neoprene Washers
  
• (4) 1/4" SAE Stainless Steel Washers
  
• (2) 1/4"-20 Jamb Knobs
  
• (6) 1/4"-20 11mm Stainless Steel Nuts
  
• (1) 4" PVC Cleanout Cap, Square Head
  

The first operation is to drill the holes for the electrode mounting bolts. The size was 1/4" to go with the 1/4"-20X1-1/4" 3/16" Allen cap screws.


The next operation is to drill the hole for the vinyl tubing. This should work fine with a 7/16" bit. The bit in the picture was 3/8". Careless of me not to measure the tubing to get the right bit size to begin with.


After assembly this is the finished product. The jamb nuts had to be ground a bit so they would turn in the tight space next to the square of the cap. Also, when assembling, make sure there are two threads of turn space between the first and second nut to allow for the insertion of the electrode bracket.


The underside view of the cap.


And finally the schematic of the bolt assembly.

Test Bubbler and Volume Measuring Bottles

I grabbed the water bottles I was saving to make into the test bubbler and volume measuring bottles and started wailing away on them.


The bottle and tools rounded up. Turned out I needed a 3/8" drill bit which wasn't in the fancy Hitachi drill bit set. No problemo, as I have a tool box full of just drill bits.


Now I drilled 2 holes in each cap from the bottom using the wood block as a backing. I drilled into the wood a bit to ensure a clean hole. A punch of some sort would work as well, but I didn't have one on hand.


Measuring the tube for the volume displacement bottle involved pressing the tube through the cap until the tub touched the bottom of the bottle. Then measure about 2 inches above the cap and this is the cutoff for the longer volume displacement tube.


There are four short tubes required for this setup and I cut them about 3-4 inches long, leaving the final length for the test bubbler. The input tube only needs to protrude into the water of the test bubbler a few inches so the length was more than adequate at 1/2 to 2/3 of the way into the bottle.


I then cut two lengths of 3/8" clear vinyl tubing, glued the tubes into the bottle caps and connected everything together.






And here's a schematic of the test bubbler and volume displacement bottles.