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The Ins and Outs of Metal Fabrication

We have so much amazing material surrounding us that we take its greatness for granted. Have you ever closely examined the steel buildings that are now our churches, schools, and fire departments? Because these gigantic steel girders blend into their surroundings, they are often overlooked.

We are surrounded by objects made out of metal every day. Automobiles, buildings, sculptures – all contain metal in some form. Metal fabrication is an essential part of each person’s life. Steel and iron are reliable and a lot more secure than wood.

This article is for those of you who may not be very familiar with metal. In this article we will show you how metal is formed as well as show you the steps it takes for fabrication.

To start with, what does metal fabrication involve?

In simple terms, converting metal shapes into a finished product is known as metal fabrication. Small metal mixing bowls and giant metal cement mixing machines must all be fabricated. Metal fabrication is a category that includes metal forming, cutting, bending, welding, and finishing.

What are the different types of metal fabrication?

The three basic categories of metal fabricating are structural, industrial, and commercial. The process of manufacturing bridging and building components is known as structural fabrication. The manufacturing of processing equipment and support equipment for industrial use falls under the definition of industrial fabrication. The major chunk of metal items bought by consumers is produced by commercial metal fabrication.

What are the steps that are followed when the metal is cut?

Metal may be cut in two ways. One way is when sharp blades are rubbed up on the metal. Sometimes, though, the metal is just completely cut out. The process of applying a large amount of pressure on a small area until the metal breaks or fractures is known as shearing. It is much like a giant pair of scissors, and the process is always the same. Removal of metal, however, can be done using varying methods including abrasives, electric arc, laser beams, or torches. These are all widely used processes for cutting metal. In the field of fabrication, abrasive wheels and cutting torches predominate because they are relatively easy to use and portable. Stationary equipment (e.g. water jet beds, plasma tables, and laser cutters) aren’t used as much, yet they give amazing results with precise tolerances.

In order to get the skills required for metal fabrication, where would you go?

Certified learning centers and on the job training are the two types of metal fabrication instruction that are most common. Either way, a person must possess sufficient knowledge of the necessary skills before they can obtain work in the fabrication industry. The skills of the metal working industry are maintained and promoted by several agencies including the American Welding Society, the American Institute of Steel Construction, and the American Petroleum Institute.

Like any other field, the initial stage of metal fabrication is design, the conception of an idea that will eventually lead to the finished product. When required, engineers will check that the materials used are of the strength that is needed. The fabrication facility orders materials after receiving the plans. Depending on your design plan, materials will be cut, shaped, and welded together to make the product. Workers inspect each product before it leaves the plant to make certain it has been properly made for its purpose.

Now you know all you need to know about metal working.

Model Trains – Companies Involved

The collectors of brass HO trains are always on the look out for the trains and where to buy them. The companies that involve themselves in supplying these collectibles can be classified as manufacturers, importers and distributors.

Most of the companies that manufacture HO model trains sell them online or in their own retail showrooms. Some of them import from China and Korea and sell them directly or are the distributors of the HO brass model trains. Many companies not only sell the trains, but also tracks, bridges, HO scale passenger equipment kits and locomotive HO. They also have model trains of other scales like O, HOn3, On3, G, N, etc.

Some of the manufacturers have come out with fine detail models in white metal and etched brass. Handcrafted brass model HO trains, Brass O scale steam locomotives, freight cars and girder bridges, etc are manufactured by some companies. Some manufacturers cater to the British railway modelers in 4mm or 7 mm gauges which have prototypes of early 19th century carriages. Manufacturing is also done in some European countries like France, Germany and United Kingdom. Some manufacturers attend to the special needs of the collectors and create custom-made versions of trains exclusively for them.

2-rail and 3-rail models are the models that are the classification system used according to the tracks and most of them are 2-rail models. The prototypes that can be found in the market are Sweden, Italian locomotives, North American or European railways. HO scale passenger equipments available in the market are made of brass, wood, plastic or nickel silver.

Importers take pains to find the right kind of manufacturing companies overseas and get them make available in their own countries. Most of them also import accessories like detail parts, scratchbuilding supplies, rolling stock, scenery flats, buildings, etc in the various scales apart from the model trains. These would be suitable for both collectors or operators.

The distribution system is usually a network across several states and countries, bringing up several kinds of model trains. The retailers obtain all kinds of models from these distributors and are the mediators to get them to the collector. The Lionel HO trains, Bachmann HO trains, Atheran HO trains, Marklin HO trains, etc are all well-known versions of the various model HO trains.

Online suppliers add up their stock with newer versions of trains and also new models of steam, passenger and freight trains. Most of them also buy the model trains if the collector or others wish to trade or dispose them for some reason. Internet is an ocean of information for the collectors for the latest items and display methods and models. Various kinds of electrical, electronic and digital layout planning and equipments are available for displaying running models of the precious Brass HO trains.

Pinch Valve Sleeves

Many industries use specific valves, called pinch valves, to control fluids, wastewater, slurries, abrasives and corrosive chemicals. Pinch valves are constructed of a heavy-duty, rugged pinch mechanism that positions a sleeve. The valve offers maximum durability and ensures precise flow control in many industrial processes.

Inside every pinch valve is a sleeve that is crucial to the performance success of the valve. This sleeve enables a pinch valve to have a bi-directional, drop tight shut off with which to control flow. Most pinch valve sleeves are made of flexible elastomer compounds, many of which resemble rubber in composition and feel. Because a sleeve’s composition is crucial to the success of the valve’s application, valve manufacturers offer different elastomer options from which the sleeve can be constructed.

The many uses of the pinch valve

Because pinch valves are useful in a wide range of industries, the ability of a purchaser to choose the desired sleeve composition is paramount. Commonly used in the mining industry, a pinch valve’s tough construction makes it ideal for use on harsh and abrasive mining slurries. Pinch valves can also be useful in demanding wastewater treatment applications. For example, a pinch valve’s accurate, repeatable linear flow control and drop tight, bi-directional shut off make this valve type a good choice for sludge and raw sewage control.

In the power industry, pinch valves are an important component used in lime and ash handling – two tough services commonly found within a power plant. The abrasion-resistant, self-cleaning, and flexible elastomer sleeve of a pinch valve won’t scale, bridge, plug or freeze on slurries. Pinch valves can also work in the treatment and handling of corrosive chemicals. Because there is no packing to maintain and no cavities, seats, or cam action to bind valve operation, pinch valves are often used in corrosive chemical applications.

Pinch valves can also be used in pulp and paper mills. Pulp stock, coating and recycled paper lines are some of the most difficult applications for a valve. The flexible elastomer sleeve of a pinch valve are able to withstand these abrasive services. Pinch valves can also be a great asset in food and beverage plants, cement/sand/silica factories, refineries, pneumatic conveying, and scrubbing.

A sleeve elastomer for every application

The multitude of uses for pinch valves require that purchasers be able to choose specific sleeve compositions and styles for various applications. A pure gum rubber sleeve, for example, is not suitable for the handling of strong acids, but might be appropriate for food manufacture or alcohol distillation. The application of a particular pinch valve, including the temperature range to which it will be exposed, dictates which sleeve elastomer a valve customer should choose.

Pure gum rubber sleeves are resilient and abrasion-resistant. They can handle an incredibly wide temperature range, from -50 F to 180 F, and they are extremely flexible, as well as non-marking. They are composed of natural rubber, and are most suitable for organic (or, carbon-based) acids, and mild chemical compounds, including alcohols. Strong acid and basic solutions, oils, and solvents are some of the chemicals that this type of pinch valve sleeve is ill-equipped to handle.

Neoprene pinch valve sleeves are synthetic rubber sleeves composed of chloroprene polymers. They handle a slightly wider temperature range than pure gum rubber sleeves do, working well with temperatures up to 220 F. Neoprene is chemically inert, and works best in the handling of moderate acids and other chemicals. Unlike pure gum rubber, it is strong and resilient enough to handle products containing ozone, as well as some oils and fats. Neoprene is more resistant to abrasion than is gum rubber; however, it can be eroded or weakened by oxidizing acids, ketone, ester, and chlorinated hydrocarbons.

Sleeves composed of chlorobutyl elastomers, or chlorinated butyl rubber compounds, handle major temperature ranges, from -60 F to 300 F. These sleeves are known for their good abrasion resistance and their ability to handle animal and vegetable fats. However, other types of oils are too heavy for chlorobutyl elastomers to handle — as are solvents, which can break down the rubber.

The trademarked name of nitrile (a triple-bonded carbon-nitrogen compound), Buna-N can be used to make sleeves suitable for -40F to 240 F temperature ranges. These types of sleeves can be useful in chemical manufacture and chemical engineering because they can handle chemicals and solvents. They are not suitable, however, for ozone, ester, ketone, or nitro/chlorinated hydrocarbons. Meanwhile, Hypalon, a trademarked name for a chlorosulfonated polyethylene compound, is used to construct sleeves suitable for temperature ranges between -60 F and 275 F. This durable compound can handle quite strong acids and bases, as well as freon, ozone, alcohol compounds, and alkalines. This type of pinch valve sleeve should not be used with ketone, ester, or various aromatic and chlorinated hydrocarbons. Hypalon resists weathering quite well, however.

EPDM (or ethylene propylene diene monomer) valve sleeves are excellent for use with fats and oils. These valves — made of the material used to seal vehicle doors, windows, and the like — can withstand temperature ranges between -60F and 300F. They should not be used, however, to work with mineral oils or solvents. They also weather well. Viton, a type of synthetic rubber used commonly in O-rings, can also be used with animal and vegetable oils, as well as with acids. Though this type of sleeve performs poorly at temperatures lower than -10 F, it performs quite well at temperatures up to 400 F. Viton sleeves also display excellent tensile strength.

Each of the many uses of pinch valves requires careful consideration of the valve sleeve that is most appropriate to the process for which the valve will be used. With the variety of sleeve elastomer options available, it is no wonder that pinch valves are applicable in so many situations and for so many processes.