Most people know that wood is not really a recyclable building material except for grinding it up and using it for other uses not necessarily related to the building industry. Its ground up products can be used for mulches, surfacing materials for pathways and bedding products. It can be pressed into boards but it will never be used for structural purposes after being recycled. Unlike wood, metal can and is recycled into structural building materials and can be done again and again.

It is part of a category of division five construction materials in the greening of the construction industry. This division includes structural steel, metal deck, cold-formed metal framing (steel studs), railings, sheet metal fabrications, castings and ornamental metals. These categories can be made from a variety of different metals including steel, galvanized steel, stainless steel, aluminum, copper, bronze and brass. For those who are looking for recycled products, and who isn't these days, steel, aluminum and copper have the ability to easily be recycled. Actually all of the metals presented here and including some not presented here have the ability to be recycled. When it comes to building materials, metals are unique since they can be re-manufactured or recycled indefinitely without losing their structural properties. With the help of the roll forming process metals are now taking on a new role in the construction industry. It is much easier to prefabricate materials like roofing, structural supports, and beams that can be used in both residential and commercial buildings.

A lot of people are not familiar with roll formed products, at least when that is the name used. Most people have seen a sheet metal roof with its scalloped appearance but didn't refer to it as roll formed. As the use of metal becomes more prevalent in the industry, descriptors like roll form channels will be used more and more in the vocabulary of construction workers and the general public.

In order for metals to become part of the greening of the construction industry, people need to have a mindset change in the way they look at metals. Metals are not typically looked at as environmentally friendly materials. The cost of mining, manufacturing and transportation of metals are some of the highest in the construction material world and it's going up as speculators raise the prices. This, however, doesn't take away the positives like recycling, strength, durability and very little out-gassing, putting them into environmentally friendly materials.

Ready to choose again among PTFE Teflon low friction coatings? That's fine. But hold off for just a moment. Has your current coating really failed you?

The answer you will find is in understanding friction and wear.

PTFE, also known as polytetrafluoroethylene, exceeds many of the properties of other thermoplastics. Let us look at its surface characterizations for adhesion and deformation when sliding wear is considered against metal.

Based on its comparatively low modulus value, any surface asperities of DuPont PTFE will measurably deform under load. This means higher loads can produce lower friction.

Of course, coefficients of friction will rise with increasing temperature. Mostly the result of binder choice within the coating, so be sure you can identify your temperature requirements. Once you reach upper limits of continuous use, melting point, or glass transition temperature, drag can increase significantly.

Sliding wear is normally measured by material loss over time. So consider these two primary mechanisms for wear: adhesive wear and abrasive wear. Between the two, adhesive wear will always be preferable.

How do you distinguish between the two forms of wear? Well, if it is adhesive wear, you should see developing fine powders at the interface between the fluoropolymer coating and metal counter face. This is a good indication that surfaces are wearing the way they should. However, phenomena like deep corrugations, grooves, or gouges within the coating will quickly indicate pressure velocity limits of the material have been violated. Usually, too, assuming the environment remains unchanged, abrasive wear occurs quickly. Sometimes, failure is immediate and catastrophic.

Article Source: http://EzineArticles.com/?expert=William_Gunnar

Pumping of liquids is almost universal in chemical and petrochemical processes. The many different materials being processed require close attention to selection of materials of construction of the various pump parts, shaft sealing, and the hydraulics of the individual problems. A wide variety of pumps types have been developed to satisfy the many special conditions found in chemical plant systems; however, since all of these cannot be discussed here, the omission of some does not mean that they may not be suitable for a service. In general, the final pump selection and performance details are recommended by the manufacturers to meet the conditions specified by the process design engineer. It is important that the designer of the process system be completely familiar with the action of each pump offered for a service in order that such items as control instruments and valves may be properly evaluated in the full knowledge of the system.

A pump is a physical contrivance that is used to deliver fluids from one location to another through conduits. Over the years, numerous pump designs have evolved to meet differing requirements.

The basic requirements to define the application are suction and delivery pressures, pressure loss in transmission, and the flow rate. Special requirements may exist in food, pharmaceutical, nuclear, and other industries that impose material selection requirements of the pump. The primary means of transfer of energy to the fluid that causes flow are gravity, displacement, centrifugal force, electromagnetic force, transfer of momentum, mechanical impulse, and a combination of these energy-transfer mechanisms. Gravity and centrifugal force are the most common energy-transfer mechanisms in use.

Pump designs have largely been standardized. based on application experience, numerous standards have come into existence. As special projects and new application situations for pumps develop, these standards will be updated and revised. Common pump standards are:

1. American Petroleum Institute (API) Standard 610, Centrifugal Pumps for Refinery Service.
2. American Waterworks Association (AWWA) E101, Deep Well Vertical Turbine Pumps.
3. Underwriters Laboratories (UL) UL 51, UL343, UL1081, UL448, UL1247.
4. National Fire Protection Agency (NFPA) NFPA-20 Centrifugal Fire Pumps.
5. American Society of Mechanical Engineers (ASME).
6. American National Standards Institute.
7. Hydraulic Institute Standards (Application).

These standards specify design, construction, and testing details such as material selection, shop inspection and tests, drawings and other uses required, clearances, construction procedures, and so on.

The most common types of pumps used in a chemical plant are centrifugal and positive displacement. Occasionally regenerative turbine pumps, axial-flow pumps, and ejectors are used.
Modern practice is to use centrifugal rather than positive displacement pumps where possible because they are usually less costly, require less maintenance, and less space. Conventional centrifugal pumps operate at speeds between 1200 and 8000 rpm. Very high speed centrifugal pumps, which can operate up to 23,000 rpm and higher, are used for low-capacity, highhead applications. Most centrifugal pumps will operate with an approximately constant head over a wide range of capacity.

Positive displacement pumps are either reciprocating or rotary. Reciprocating pumps include piston, plunger, and diaphragm types. Rotary pumps are: single lobe, multiple lobe, rotary vane, progressing cavity, and gear types. Positive displacement pumps operate with approximately constant capacities over wide variations in head, hence they usually are installed for services which require high heads at moderate capacities. A special application of small reciprocating pumps in gas processing plants is for injection of fluids (e.g. methanol and corrosion inhibitors) into process streams, where their constant-capacity characteristics are desirable.

Axial-flow pumps are used for services requiring very high capacities at low heads.

Regenerative-turbine pumps are used for services requiring small capacities at high heads. Ejectors are used to avoid the capital cost of installing a pump, when a suitable motive fluid (frequently steam) is available, and are usually low-efficiency devices. These kinds of pumps are used infrequently in the gas processing industry.

To properly accomplish a good and thorough ratinghizing of a centrifugal pump, the plant system designer should at a minimum do the following.

1. Understand the fundamentals of performance of the pump itself.
2. Understand the mechanical details required for a pump to function properly in a system.
3. Calculate the friction and any other pressure losses for each "side" of the pump, suction, and discharge.
4. Determine the suction side and discharge side heads for the mechanical system connecting to the pump.
5. Determine the important available net positive suction head (NPSH,) for the pump suction side mechanical system, and compare this to the manufacturer's required net positive suction head (NPSH,) by the pump itself. This requires that the designer makes a tentative actual pump selection of one or more manufacturers in order to use actual numbers.
6. Make allowable corrections to the pump's required NPSH (using charts where applicable) and compare with the available NPSH. The available must always be several feet (mm) greater than the corrected required.
7. Make fluid viscosity corrections to the required performance if the fluid is more viscous than water.
8. Examine specific speed index, particularly if it can be anticipated that future changes in the system may be required.
9. If fluid being pumped is at elevated temperature (usually above 90o F (32.2o C )), check temperature rise in the pump and the minimum flow required through the pump.
10. Make pump brake horsepower corrections for fluids with a specific gravity different from water. Select actual driver (electric motor, usually) horsepower in order that horsepower losses between the driver and the pump shaft will still provide sufficient power to meet the pump's input shaft requirements.
11. If the pump has some unique specialty service or requirements, recognize these in the final sizing and selection. Consult a reliable manufacturer that produces pumps for the type of service and applications and have them verify the analysis of your system's application.

Article Source: http://EzineArticles.com/?expert=Bustanul_Arifin

CNC Machines, Water jet Cutting machines and Granite Bridge Saw are getting very popular machineries in today’s industrial world. These are most effective, cost effective and fastest growing method to cut materials.

CNC Machines technology is one of the new emerging technologies used in metal industry. The introduction of CNC (Computer Numerical Control) machines has made a great impact on the manufacturing industry. These are very useful as can help to cut curves as a straight line; Complex 3-D structure can be produce and thus reduced the human actions. This is one of the reasons so that CNC Shop are getting so popular and helpful. It gives more flexibility in holding the parts in manufacturing and to change the machine to produce different components.

CNC machine has the functions of milling, grinding, polishing and sculpting.
It is especially suitable for producing high grade basin board and other abnormal products
Made of stone, ceramic, glass and micro-crystal stone. The machine will automatically
finish the processing of any required profile by simple setting. The products are of high precision and good glossiness rate.

One more example of same type of tool is Water jet cutting Machines, which are capable of slicing into metal or materials with high velocity and pressure. It is often used for both fabrication and manufacture of parts for machinery and some other devices.
Water jets can be used to cut materials as diverse as fish sticks, 'gas station' sandwiches, and titanium. But still there are some materials that cannot be effectively cut with a water jet cutter like, tempered glass, which shatters when cut, regardless of the cutting technology used.

Water jet cutting technology is the most efficient, cost effective and fastest growing method to cut materials. Due to its versatility and ease of operation, fabricators are quickly realizing the vast potential of these machines. Water jets (or abrasivejets) can cut virtually any material in any shape with no heat distortion or mechanical stress usually caused by other methods.

Granite Bridge Saw are also getting very useful for industrial uses. Bridge Saws also include different varieties for the different purposes in Small laboratories or industries as Marble and granite bridge cutter, diamond saw machine into rails, electronic bridge shape sawing machine, Compactness and sturdiness etc.

Marble Services Co. has contracted with many corporations, businesses and residents to perform hundreds of restoration and refinishing projects, both large and small. Following the Northridge Earthquake we restored many damaged marble statues and stonework, in many cases masking any evidence of damage.

Article Directory: http://www.articledashboard.com

While this type of system provided weight information for many years, it was very far from ideal. The pivots and bearings moved against each other, and would experience wear over time. This would cause inaccuracy, and required the scale o be serviced regularly. Because the platform rested on its bearings, there was a certain amount of free motion on the platform. The pivots and bearings, and the supporting lever arms forced the overall height of the scale to be six inches or more. This could make it difficult to place loads onto the scale platform. The scale was also expensive to manufacture, as there were a significant number of parts. There were no practical ways to use the scale to control other devices. Some elementary types of micro switches could be rigged onto the scale, but they were neither accurate nor convenient.

Some early types of digital platform scales simply replaced the counterbalance arm with a single load sensor. This type of sensor converts a mechanical force into an electronic signal. The signal is amplified, and then converted from its original analog form into a digital number which is displayed on the electronic indicator. This had the major advantage of being much easier to read than the older mechanical types. It could also interface with other devices, such as printer and computers. But it still suffered the rest of the disadvantages of the older mechanical type.

The next step was to place a single large capacity load cell in the center of the scale platform. This directly accepted all of the weight on the platform and eliminated all of the pivots, bearing and levers. The primary disadvantages of this method is that the load cell had to be quite large in order to provide support for loads that could be off center on the platform. Therefore the platform height remains too large for easy use. Also, the size of the scale platform were kept fairly small, with 1000 lb capacity scales at approximately 15” x 20”, in order to avoid the off center difficulty. Even with the smaller platform, there is still some movement of the platform when the load is not well centered.

A more ideal solution is to provide a load cell under each corner of the scale platform. This method is used by Arlyn Scales to provide the electronic platform scale with the best feature set. The scale platform can now be quite large, ranging in size from 20” x 27” all the way to 48” x 48”. But the scale profile can be exceedingly low, at 1 7/8”. Furthermore, with no pivots or bearings, the scale will remain quite accurate over time. To provide even better performance, the Arlyn digital scales use stainless steel for the load sensors, which provide excellent resistance to shock loading and overload abuse. A very wide range of electronic features include a USB interface which can send data to a computer, or to a USB memory stick for purposes of logging the data. Ethernet connections are also available, so the scale can be monitored from remote locations. The optional setpoint controller allows the scale to control valves, pumps and solenoids for automatic filling.

Article Directory: http://www.articledashboard.com

Certified Industrial Maintenance Mechanics (CIMMs) are responsible for preventive, predictive, and corrective maintenance. They are multiskilled individuals whose expertise is primarily mechanical in nature as opposed to instrumentation or electrical.

CIMMs have a minimum of five years of relevant work experience in the maintenance mechanic field or three years experience and a two-year associate degree in maintenance or a related field.

This question is from Performance Domain III: Troubleshooting and Analysis.

CIMM question

What are two resources available to a maintenance mechanic to help verify a problem?

A. The capital plan and the installation manuals

B. The operator of the system and the equipment historical data

C. The plant engineers and the supervisor

D. The operations supervisor and his crew

CIMM answer

The best answer is B, the operator of the system and equipment historical data.

The maintenance mechanic should always have a conference with the operator to discuss temperature, noise, pressure, flow, and other working parameters. After conferring with the process operator, check past history for a similar failure and repair.

At the beginning of the investigation phase for the industrial workstation project, a team from R&D and marketing set out to answer the question "what makes an industrial workstation different from a standard workstation?"(dagger) Dozens of customers in the measurement and industrial automation markets were visited to help us understand their needs that go beyond the features provided in HP's line of standard workstations. This article addresses the mechanical design aspects of the differences between standard and industrial workstations, and the design strategy we used to meet the needs of customers in the industrial marketplace who use or could use engineering workstations.

Serviceability

Unlike standard workstations, industrial workstations are intended to be incorporated in large, very complex manufacturing processes that produce products worth extremely large amounts of money per hour. The cost of downtime demands the highest level of serviceability. Trade-offs for cost that compromise serviceability cannot be made. Our goal was to provide access to all service-level components in less than three or four minutes.

All service-level components in the Model 745i and 747i industrial workstations including the backplane can be removed and replaced from the cable end of the computer while the computer chassis remains mounted in the rack. This feature sets a new standard for serviceability in this industry. To make the serviceable modules, or bricks,(double dagger) easy to remove, an extractor handle was developed which holds a captive spring-loaded retracting screw (see Fig. 2). The handle provides a trigger grip for the index finger and a fulcrum surface for the thumb when removing adjacent bricks. The handle also provides a surface to push on while seating the bricks. Regulatory compliance dictated the use of a tool to remove all bricks. The captive screw, which is housed in the handle, visually pops forward to indicate to the operator that the brick is unfastened. Once the bricks are removed an internal wall (see Fig. 3) swings up to unlatch so that it can be taken out of the cabinet to allow the customer to remove the backplane by undoing a single captive fastener located on the backplane.

Connectivity

In addition to the robust core I/O capabilities offered by HP's standard workstations, the Models 745i and 747i provide an HP4B interface as part of the core I/O. To provide I/O functionality that goes beyond that offered as core I/O, expansion slots are provided. The number of slots requested for industrial workstations is not only greater than for standard workstations, but the types of I/O slots are mixed. Besides the core I/O, the current HP standard workstations only provide EISA slots, which support several I/O protocols.(2) In addition to supporting EISA slots, the Model 747i also supports VMEbus. The package for these machines was designed to be large enough to be able to house the larger cards such as VXIbus cards. (dagger)

Support Life

Support life is a very important consideration to the industrial automation customer. Once an industrial workstation has been designed and installed into a factory process it is rarely replaced or upgraded for reasons other than loss of support. Support life is not something that is designed in, but rather a promise or commitment made to customers by HP. The current standard workstations are supported for five years while the Models 745i and 747i carry a 10-year commitment. To reflect a long support life, the industrial design of the Models 745i and 747i has a much plainer and timeless look (see Fig. 4) than the new line of standard workstations.

Reliability

In many standard workstation applications the hardware becomes obsolete long before physically wearing out because of reasons such as the availability of lower-cost machines or machines with faster graphics engines. With industrial workstations this may not be the case because certain items like the fan may not have the same 10-year or even 20-year life that a factory installation may have. For example, extensive testing was done on fan bearing systems to select the best fan for the Models 745i and 747i, but the life expectancy of the fan is still not greater than the service life of the workstation. Thus, the power supply carries a fan-tachometer signal and an overtemperature signal, and is serviceable. More details relating to fan and airflow reliability are discussed later in this article.

Mechanical system industry manufacturers, labor unions, contractor organizations, educators, students, consultants, individual contractors, and others have joined together to form the Green Mechanical Council (GreenMech). GreenMech, an international not-for-profit organization, was formed in part, "to bring bold, decisive, and innovative action to the critical question of global warming. GreenMech members believe that no less than the planet's future is at stake," according to Dan Chiles, GreenMech chairman of the board of directors.

Tom Meyer, executive director, describes GreenMech as a "Clearing house of information and education for designers, installers, and service techs who deal with mechanical systems every day. They are the people who can have the most immediate effect on reducing energy consumption and greenhouse gas emissions. We give them the information to take green components, to make them into a green system and to commission and service the systems to keep them green.

"One of the benefits to manufacturer involvement is there is a feedback communication from the field to the manufacturers making practical changes and improvements to products based on field experience and ingenuity. It's a win-win deal," Meyer added. "There is no doubt the world we know will change. GreenMech was formed to ensure the change is one the world can live with."

The organization's founding members include Watts-Radiant, HVAC Excellence, Legend Valve, Mechanical Contractors Association of America (MCAA), Mechanical Service Contractors of America (MSCA), Mechanical Contractors Education and Research Foundation (MCERF), the FloorHeat Company, the United Association of Plumbers and Pipefitters (UA), and Ferris State University.

Chiles said the organization joins the U.S. Conference of Mayors, the American Institute of Architects (AIA), the USGBC, and others in rising to the "2030 Challenge." "We accept the challenge to meet building performance targets of a reduction in fossil fuel consumption by 60% before 2010 stepping by decade to a goal of totally carbon neutral buildings by 2030."