Plastic Pipes: Pipe Innovation

Plastic piping has been an innovation in the piping industry used for many years now. Although not all plastic pipes are suitable replacement for more traditional piping materials such as concrete or metal, plastic piping has many unique properties making it a better option over other piping materials considering other factors such as the weight of the load transported and the corrosiveness of the fluid.  

There are many instances where a plastic pipe can be a better option over a metal pipe. In the economic aspect, plastic piping is cheaper because installation is easier and it is expected to last longer since it can withstand corrosion with its smooth surface area.  Costs for purchasing thermal insulators are also avoided because plastic piping greatly reduce heat transfer due to its much lower thermal conductivity. Because it is lightweight and flexible, small plastic pipes can easily be maneuvered around making it more popular among consumers who use it in residential plumbing.

Speaking of health security, all plastic pipes sold for plumbing purposes are nontoxic and have been approved for carrying potable water. CPVC and PVC pipes don’t rust like galvanized pipes so it eliminates any rusty or metallic taste in drinking water that other pipes can leave. Since they don’t corrode and are not subjected to scaling, material build up in the inner surface is avoided. This build up, common to piping with metal materials, blocks water flow, decreases water pressure, and may cause back up in drainage. Plastic pipes allow water to flow unhindered for a long period of time.

In terms of environmental friendliness, plastic piping is better because it is odorless, non-toxic, fully recyclable, and based on scientifically conducted Life Cycle Assessments (LCAs),has “greenness” the other piping materials do not have.

Here is a video of JM Eagle, the leading manufacturer of plastic and PVC pipes highlighting their innovations.

Here is another innovation showcase in thermal pipes by Acrolab

Pumps: Ancient and Modern Times

Pipes are fundamental equipment commonly used in industrial plants. They are the ones transporting fluids or mixture of substances which are either being in the treatment process or being moved for storage or disposal. But aside from pipes, there are a lot of necessary things still needed in order to actually transport fluids.  Fluids don’t usually flow by themselves unless they are flowing down from an elevated position. Elevated source of fluids is not common in a usual industrial plant so the fluid needs something to induce its flow.

That is why pumps are also needed. Pumps force the fluid to flow into a pipe usually from a lower to a higher position. There are various kinds of pumps available nowadays. One kind is preferred according to the design requirement of a certain process where it is required. Each has its own advantages and disadvantages.  But there is a continuous innovation in those that are used in the industries today aiming to improve efficiency and save as much power as possible.

Even though chemical engineering is a relatively young discipline, some unit operations and processes have been in existence way before chemical engineering was first established. For example, transporting water has been a problem that needed addressing even before industries started. And water pumps in fact have moved water from a place to another place for centuries. They remain today as invaluable tools to provide water for irrigation, drinking and cleaning. Ancient pumps took advantage of natural forces like wind or water to provide a pumping mechanism, while today's pumps tend to use electricity. However, the mechanisms behind ancient pumps are still in used today- a reason why they are considered one of the greatest inventions of the ancient world. I listed here some of the interesting pumps with their current uses.

• Shaduf (Swipe Pump) -This was the first pump which was invented in 3000 B.C. in ancient Mesopotamia. The swipe, or shaduf, pump is usually positioned right next to a riverbank. It is made with a lever pivoted on two posts placed in the ground upright. On one end of the lever a pole is placed with a bucket attached. A stone or anything that is heavy enough is attached to the other end to act as a counterweight. Water is retrieved by pushing the pole down until the bucket is filled with water, then the counterweight would help raise the bucket back up. 

• Screw Pump- The screw pump was used widely by the Egyptians in the ancient world but the great mathematician Archimedes was credited with inventing what is known in history as the Archimedean screw around 250 B.C. This was perhaps Archimedes' best known invention and often listed among the great ancient inventions because it is still in use today. This pump was made using a metal corkscrew shaped pump that drew water upward as it was rotated.

• Bucket Chain  - The bucket chain pump was invented as early as 600 B.C. It is made up of a series of buckets that passed over a pulley wheel. Historians believe the bucket chain pump irrigated the Hanging Gardens of Babylon. Historians state that the gardens were built for King Nebakanezer 's wife, Amytis, who missed her hometown when she moved to Babylon. Babylon was very flat and dry, with very little rain and therefore had very little greenery. Her hometown was very mountainous so Nebakanezer had the gardens built for her so it would resemble the place where she came from. The gardens were huge and contained many types of flowers, fruit, animals, and waterfalls, which were said to have been from places all over the world. The bucket chain has been used for centuries and perhaps the earliest known hand cranked device invented. 

An artist sketch of the Hanging Gardens of Babylon

Miscellaneous Rules of Thumb in Piping

Engineers are the ones who design and built working structures in various industries based from applications of the physical sciences. As part of the engineering sense, estimation and using rules of thumb are important especially in the design and in the field itself. As they say, engineering is more practical art than science. As such, its most successful practitioners obey simple rules like these.

This was initially a surprising discovery for me. Sure, I've heard a lot of senior schoolmates who said that most of the things learned in academics are not used in actual work.

Well, it has to be because I thought that the work would be specialized. That was my thinking until I've come across an article entitled "Jack's Rule of Thumb".

All that we learned from the classroom were just to give us insight. The academia's detailed analysis of fundamental engineering concept are not really the ones used by engineers to built actual things. 

An example from the article says that civil engineers rarely analyze loads in small structures like what comes out in the ES exams. What they do is to refer to their handbooks, for instance, to look up what standard beam to select to support a floor of a particular size. Sure the engineers could painstakingly re-derive such data, but in practice they do not.

Rules of thumb are the basis for the design of most real-world products. They are subject to exceptions and revisions but they are very useful in giving near accurate estimations.

Here are some miscellaneous rules of thumb used in the field of chemical engineering especially in constructing pipelines.   

• Substituting a globe valve for a gate valve in a piping system is similar to adding another 100 feet (31 meters) of piping to the system. 
• Suction piping should be at least one size larger than the suction flange at the pump.
• Use eccentric reducers rather than concentric reducers at the pump suction. Concentric reducers will trap air. 
• In a mixer, the liquid level must be at least one and one half diameters of the blade, above the blade.
•  Vortexing (spinning, turbulent flow of fluid) can occur if any of the following conditions are present:

Water Vortex

1.  Low liquid levels.
2. Liquid level falling greater than 3 Ft./sec. (1 Meter/ sec.)
3. There is a large concentration of dissolved gases in the liquid.
4. High outlet velocities in pipes leaving vessels. Generally greater than 10 feet/sec. (3 meters/sec.)
5. Liquids near their vapor point.
6. High circulation caused by asymmetrical inlet or outlet conditions.
7. Inlet piping too close to the wall or bottom of the tank. Consult the Hydraulic Institute Manual or a similar publication for recommended clearances.

• Pipeline pigging ( the use of pipeline inspection gauges or 'pigs' to perform various maintenance operations on a pipeline) 

An example of a pipeline "pig".

1.  In sizing plates, an aluminum disc with a diameter of 95% of the nominal inside diameter of the pipe is  typically attached to the front of a pig and is inspected for marks at the end of the run.
2. A gauging pig can be placed inside the pipe and pulled along the pipe. If the lay barge moves forward and the pig encounters a buckle or dent, the pull line will become taut. This indicates that it will be necessary to pick up and replace the dented section of pipe.
3. To measure pipe internal geometry  caliper pigs are used. Typically they have an array of levers mounted in one of the cups.  As the pig travels through the pipeline, the deflections of the levers are recorded.  The body is normally compact, about 60% of the internal diameter, which, combined with flexible cups, allows the pig to pass constrictions up to 15% of bore.  The results can show up details such as girth-weld penetration, pipe ovality, and dents.

Read more at http://www.mcnallyinstitute.com/02-html/2-7.html
http://store.elsevier.com/Pipeline-Rules-of-Thumb-Handbook/E_W_-McAllister/isbn-9781856175005/

PIPES and the PLUMBER

"Actually, in ChE 134 we would all become plumbers  (tubero in Filipino) because what we would be discussing is all about pipes." This was one of the earliest statements I remember coming from my instructor. Of course it was supposed to be a joke and so my seatmate that day decided to expound the joke in his way.

Seatmate: "Hey Hanna, my mom told me to shift out from chem eng'g."

Me:(raising a brow) "Eh. Why?"

Seatmate: "Because she doesn't want me to become a plumber."

The end.

The Plumber's Job

A chemical engineering course being compared to plumbing just proves that chemical engineering is indeed a very versatile discipline which is applicable to a lot of industries. Actual installation of plumbing is may not be included in the course but the science and engineering plans behind it is basic part of chemical engineering. So here is a list showing the similarity of a chemical engineer and a plumber's knowledge.

What the plumber knows that I (should) know:

1. Specifications to determine layout of water supply, waste, and venting systems.

2. Plumbing or pipping plans for hot and cold domestic water supplies.

3. Familiarity with ice-machine work, thermostatic work connected with plumbing, pipework connected with pneumatic vacuum-cleaning systems, gas piping, with making connections for gas fire-logs, furnaces, driers, boilers, and heaters. 

 4. Ensuring safety standards and build regulations.

5.  And the fact that"There is nothing in the work of the plumber which embodies physical or nervous strain, and as the work is extremely varied in character, it should stimulate the intelligence of the worker. The successful plumber must have strength, endurance, initiative, and special adaptability for his work."

Read more: http://chestofbooks.com/crafts/metal/Applied-Science-Metal-Workers/554-Work-Of-The-Plumber.html#ixzz20wZjxVG4 

Examining the scope of  a plumber's job also gives an  insight of how pipping systems are of great significance and of great use to a lot of industries.

You call a plumber when

 

  1. there's water dripping from the water pipes

2. your toilet doesn’t flush

3. your boiler or furnace needs repair

  

 

4. you need your home cooling or heating system repaired

  

5. you want to remodel your fixtures

 6. you want a another  bathroom

7. you want machines installed

 These are the common works of a plumber and these illustrates as well the of pipping systems commonly seen and used in our houses. Pipping systems are all around wherever you are. But pipping systems in large scales are seen in big commercial establishments involved in industrial processes.