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April 5, 2012

Tennis Balls, Softballs, Trucks and Power Plants
Filed under: Plumbing — Tags: — nedpelger

I love a good analogy that lets me better understand the physical world. I’ve worked around reverse osmosis water filtering systems for years, making mineral free water to rinse cars cleanly in car washes or to brew better tasting coffee in church. Yet I’ve never had a good understanding of the RO process.

From high school chemistry I remember that osmosis happens when a filter (think window screen) separates two different types of water. If the one side has a high concentration of a mineral (say very salty) and the other side doesn’t, then osmosis occurs. The osmosis pressure helps the two types of water tend to equalize. So the very salty water and the pure water both become somewhat salty water.

The reverse osmosis process uses an external pressure to force water through the selective membrane to filter out some larger molecules. What never made sense to me, though, was the relative size of the molecules.

The Economist article,  Salty and Getting Fresh, provides a great analogy. Think water molecules blown up to the size of tennis balls. Than salt molecules are the size of softballs (about 50% bigger diameter). Viruses then become the size of trucks and bacteria the size of power plants.

Now visualizing the RO filter becomes so much simpler. I understand why filtering bacteria out of water is simple and viruses a bit more challenging but still fairly easy. Building a filter that lets tennis balls and softballs go through but not trucks or power plant sized objects wouldn’t be too challenging. And it wouldn’t clog.

I also better understand why desalinization has been such a challenge over the past 50 years. A filter that lets through tennis balls but blocks all softballs would have a tendency to get clogged with a great flow of balls passing through. So now we understand why RO for waste water treatment works well and why desalinization on a large scale has been such a challenge. Just remember tennis balls, softballs, trucks and power plants.


October 21, 2011

No Plumbers Like That on My Jobs
Filed under: Plumbing — Tags: — nedpelger

Here’s a 30 second smile, just what you need on a Friday.


And some more Kohler fun that may be more appreciated by all my female readers.



February 11, 2011

Old Pipes and Big Problems
Filed under: Plumbing — Tags: — nedpelger

Yesterday at a job meeting, the facility director showed a 2″ water valve with considerable corrosion. Being able to see the valve, inside and out, made it easy to see the corroded threads and the imminent failure of the valve (see the V groove in the left threads). What amazed me, though, was that our plumber was able to determine that the valve may soon leak, just by looking closely at the threads.

The plumber recommended he change the valve while he was working nearby. The facility director agreed and prevented a major water damage problem from that valve snapping at some time in the near future. The water system was only installed 20 years ago.

This morning I read that Allentown, PA had a 93 year old 12″ cast iron gas main explode, killing 5 people and damaging 47 homes. The AP noted that Dorothy Yanett, 65, was in her living room with her husband awaiting the evening news when she heard a series of booms.

“Everything falling and crashing, glass, just a nightmare,” she said. She found glass in the shoes she was going to put on to leave the house. “There was no odor, there was no smell. Then it was like all hell broke loose.”

The fascinating part of the tragedy is that UGI (the gas utility) had just leak tested that section of piping four days ago. There were no leaks.  But when the fire department tried to extinguish the blaze, they struggled with the 12″ gas main feeding the flames like a huge Bunsen Burner. Due to a lack of valves in the old line, the fire fighters were unable to put out the blaze until workers dug to the pipe and foamed it closed. The aftermath is shown below:

Think about America’s 2.5 million miles of gas and liquid piping, much of it installed many decades ago. Along with the rest of our aging infrastructure, the underground piping will soon need lots of repair work. While a huge cost for our society, it will also be an opportunity for those in construction, especially for those who figure better ways to solve the problems.


November 6, 2010

Faucet to Fountain in a Pinch
Filed under: Plumbing — Tags: — nedpelger

I love creative designs and I love being hydrated. I find the more water I can make myself drink, the healthier I am. The fun product shown below turns an ordinary water faucet into a drinking fountain with just a pinch of the fingers.

The Tapi by Dreamfarm (an Australian company) provides a colorful plastic devise to slide over the faucet and shoot water up in the air. The Dreamfarm website has direct shipping or stores stocking the Tapis located all over the world. I just bought one, from Australian, for $7.95 including shipping. We live in an amazingly cool world. Don’t forget to appreciate that today.


October 23, 2010

Champion 4 Toilet Saves a Life
Filed under: Plumbing — Tags: — nedpelger

While reading Professor Toilet’s blog (don’t even ask), I came across a hilarious Home Depot review from a very satisfied toilet customer. I especially loved his comment about his mother-in-law’s “steady diet of broccoli, cabbage and gravel.” I’ve copied the review of the Champion 4 toilet below.

“I love my wife. And she loves her mother. And so when my mother-in-law is in town, we treat her as we would any guest and let her use the bathroom. Over a 7 year period, she has clogged the toilet no fewer than 30 times (often twice in a day) No, this is not a letter to WebMD but rather a note of acknowledgement that the Champion 4 has not only saved my marriage but possibly a woman’s life.

It was after her last visit to my house to offload what I can only assume is a steady diet of broccoli, cabbage and gravel that I decided to take matter in my own hands. Vowing to solve the problem once and for all, I strode in to the local Home Depot and after pausing to price the cost of a tarp, a shovel, a large bag of lye and 7-10 years in federal prison I spoke with a nice man in plumbing. After letting me vent and shed a few tears, he directed me to the Champion 4 toilet.

You know those moments in your life when the world slows down and all the ambient noise gives way and you are filled with a calm feeling of fulfillment? The birth of my children, hitting the game winning double in the state quarterfinals, college graduation and now this. The Champion 4. Read the other reviews that talk about ease of installation, water flow and seat height–they are all true. It is a great toilet and has operated flawlessly for sometime now but to me it is much more. It is so much more.”


December 24, 2008

The Mystery of Frozen Water Pipes
Filed under: Plumbing — nedpelger

Dereck was right and I was wrong. There, I’ve said it and settled my bet with Construction Supervisor Dereck Hench about a recent fiasco. We had several sprinkler pipes freeze, break and leak on an apartment project with this recent cold weather. As Dereck and I and several others evaluated the installation and tried to understand what we need to change, I mentioned that pipes don’t break when they freeze, but when they thaw and expand.

Dereck told me that pipes burst when they freeze. I patiently explained that everything contracts with cold and expands with heat. Dereck asked why a gallon jug in the freezer expands and blows out the sides of the container? I knew that phenomena was true, but couldn’t think of an explanation for how it fit into my theory.

Abner, an Amish carpenter who works for Dereck agreed with me, so we both took turns abusing Dereck for being so confident and so wrong. When Dereck told Abner he’d buy him lunch for a week if Dereck was wrong, I started to lose my sureness.

And sure enough, a quick internet search teaches me that water uniquely expands when it freezes.  The water molecules line up differently as the water freezes and have more open space between, creating a volume increase of about 9%. Dereck was right and I was wrong.

So what was our sprinkler pipe problem? We needed to have a dry pendent sprinkler head poking out onto the balcony which creates a challenging situation (breaking the basic rule of keeping water lines away from exterior walls).  We determined that the insulation needs to be done extremely carefully in this area and not be allowed to be moved prior to drywall. Our exact fix will involve spaying expanded foam insulation on the sprinkler pipe in the exterior wall to guarantee that the insulation remains exactly where we need it.