white cement and its characteristics....

White cement has become the part and parcel of each house.It has become an essence and necessity for an outstanding look.White concrete in all three aspects of economic, social, and environmental has shown an outstanding sustainable development resulting in greatest popularity with an increasing graph.It increases the durability,reduces the permeability and enhances the overall durability of the concrete. This, in turn, enhances the lifespan. White cement has its unique properties and uses. White cement is produced from raw materials low in coloring elements such as iron, manganese and chromium, normally utilizing high grade limestone, white clay and pure silica as raw materials .Now in this modern world it has a wide spread of uses.Mostly it is used in terrazzo,glass fibre reinforced concrete,as a concrete countertops,roof tiles,cold weather construction,sound walls swimming pools and spas ,etc.It has created wonders in aesthetic purposes. Greater reflectivity will increase visibility,hence it reduces the level of artificial lightning ,enhancing road safety,increase popularity of monumental beauty,dams and bridges. larger surface area and fineness adds to its superiority by making its use in repair works and tile formation and floors It reflects the heat and prevents the seepage ,used to produce Highly adhesive dry-mixes with low shrinkage and no efflorescence.contribute to a better environment by reducing the "Heat Island" effect* economic characteristic makes it unique by Reducing long-term maintenance costs.It doesnt easily fade,eliminates the need for vibration for settling, reduces air pollution,used to make prefabricated pavers and tiles ,adhesive,paints and dry mixes.the unique properties and wide variety uses has created a greater demand of it and price.though its price is very high but overall comparatively it is economic and sufficient in cost saving in future.Its classic features and capability not only has surprised the people but has resulted in greater productionRecent data reveals that India is lagging in the rapid supply and profit market.

ADITYA BIRLA group is one of the major manufacturers having base in rajasthan.through Correct initiatives production as well as demand can be increased to 15 to 25%.Demand for white cement is linked to the economic activity in any country. Broadly, it can be categorized into demand for housing construction and infrastructure creation and government projects. The real driver of cement demand is creation of infrastructure, hence cement demand in emerging economies is much higher.

The production of White Cement requires exact standards and  temperatures around 1500+ degrees.Hence,the manufacture costs much.India is lagging behind the consumption due to several reasons,less buying because of cost, labours/mason/contractors  are to command on the material of supply and hence mostly they prefer to use grey cement because of lack of awareness or mentality of gaining money,white cement is very expensive compared to foreign countries and  competition factor.Effective methods like use of bulk bags,increase production to decrease the overall price,spreading awareness,encouraging more export through the ship , encouraging usage in infrastructures and government projects and etc ,will help to reach the milestone, maintaining contacts with tile,aesthetic related companies for more diversification and etc.

Discover The Essential Role Of Tubular Piling In Construction

Tubular piling might well sound like a particularly painful and unique medical condition to the layperson however it is actually an extremely important part of large-scale construction. Piling is traditionally made of wood and it refers to long structural beams in various shapes that are driven deep into the ground using piling rigs in order to support the structure of the building project.

Now piling comes in various forms such as concrete and steel with different shapes dependent on the technical specifications of the building project. Many factors affect the use of piling such as the load of the structure, the depth of the foundation, the ground density and the soil type. The piling can be driven into the ground or drilled in, however the advantageous benefits of driving piling is that the soil around the piling becomes compact.

Piling is used in deep foundations and the shape of piling depends on the structure being built, for large scale construction tubular metal piling is driven into the ground then filled with pre-stressed concrete. The number of tubular piles depends on the individual structure of the project and the weight that the deep foundations need to incur. H-beams or square concrete piles are used for certain projects such as domestic residences or small scale apartments.

A case study in 1960 was performed in Vietnam when building a major road from the city of Saigon North. The soil below the surface consisted of layers of muck on top of clay and sand which meant that there was no solid foundation to build on, risking subsidence under the massive weight of traffic. Massive metal tubular pilings were driven into the ground then filled with concrete. Test were carried out on them to evaluate their load capacity.

It is recommended that when dealing with piles over a certain size that tests are carried out on their load capacity and how they perform under certain weights. The production of tubular piles must be done to various standards regulated by industrial watchdogs. The process is called rolling and welding tubing where exactly circular tubes are formed by rolling sheets of metal and then welding them together.

Other forms of piling are drilled piles, underreamed piles and auger cast piles. They serve different purposes such as high load bearing or specialist systems for unstable subsurface sediment. They are essential to large-scale construction and there are a few specialist manufacturers who can provide rolled and welded tubing to exact specifications.

Under reamed pile foundation for Black cotton soil

Black cotton soil contains fine clay particles. This property  induces a great affinity to water of such type of soil. Alternate swelling and shrinkage in extensive limit during wet and dry process respectively results cracks in soil without any warning. These cracks may sometimes extent to severe limit like ½” wide and 12” deep. So building to be founded on this soil may suffer severe damage with the change of  atmospheric conditions.

Under reamed piles are the most safe and economical foundation in Black cotton soil. Under reamed piles are bored cast in situ  concrete piles having bulb shaped enlargement near base. A Pile having one bulb is called single under reamed pile.

The bearing capacity of the pile is increased by increasing the number of bulbs at the base. Such type of foundations is ideally suitable in the areas where the black cotton soil or expansive soil is beyond 2.50 meter. The basic principle of under reamed pile is to anchor the structure at a depth where ground movement are negligible due to moisture variation or other reasons.

Simple tools are required for construction of under-reamed  piles like spiral auger, under reaming tool, and boring guide. This is a well proven and  established technology for construction of foundation in expansive soils. For speeding up the construction bore and under ream for large diameter and deeper pile a  mechanical rig can be used. The construction and design of such foundation can be done in accordance with Indian Standard Code of Practice IS 2911-Part III.

Types Of Drill Bits

Drill bits are tools used in making cylindrical holes. Various types of drill bits are designed for different uses.

Drill bits are equipments or tools that are used in making cylindrical holes. Drill bits can also be referred to as a drilling machine. Drill bits are available in various drill types such as metal drills, gun drills, screw machine drills, core drills, step drills, spade drills, forstner drills, masonry drills, dental or surgical drills, wood bits, twist drills, drill blank taper drills and much more.

They are designed to cut while doing a clockwise rotating motion. Several drill bits are coolant fed. They contain a channel or hole for directing the coolant fed near to the cutting edges. The split point drill heads of drill bits are used for chip clearance and for excellent centering. Drill bits can also be used in cutting aluminum, general-purpose metals, brass, copper, bronze, ceramic, and plastic, stainless steel, steel, wood, titanium and hardened materials. Various types of drill bits are designed for different uses.

Listed below are some types of Drill Bits.

Twist Drill: It drills holes in plastic, metal and wood. This drill is currently produced with a width covering a range from 0.05 millimeters to 100 millimeters while its length is around 1000 millimeters. The most usual twist drill has a tip angle of 118 degrees. This is a proper angle for an extensive array of job. It also has a long series drill for extended length twist drills. It is not advisable to drill deep holes using this twist drill.

Diamond Drill Bit: This particular drill is used in the bathroom for updating or remodeling. It is also used in redesigning your kitchen decoration. Furthermore, it is used on ceramic, glass, tile, limestone, stained glass, marble, fiberglass, porcelain, stone, slate and porcelain tile. When using this drill, the main concern is to obtain water at the edge of the drill bit. Drilling fiberglass may be done with or without water but make sure that the fiberglass has ample amount of water just to get the drill wet.

Indexable Drill Bit: This provides an excellent performance in making short-hole drillings. Stainless steel is drilled 3x in diameter and only a short-hole must be done.

Listed below are some other types of drill bits

• Adjustable Bit: This is built with a changeable cutter blade to bore holes of various sizes. It is also used for drilling gaps for wiring or piping.

• Around-the-corner bit: It is used to cut arched holes that are stretched in corners with a diagonal cutting surface.

• Auger Bits: This drill creates drill holes in wooden materials. The drill ends have a screw head so that the bits may be self fed.

• Brad-point drill: This drill looks almost the same as the usual bits but it has sharpened point to make wood drilling a lot easier. This drill has cleaner holes other than spade bits.

• Counterbore: The drill allows a screw to be driven under the wood outside. The holes that are drilled may be filled with a plug or wire.

• Drill Saw Bit: It is used to cut holes such as wood and metal and can enlarge current holes.

• Countersink: A drill that has an angled tip design that forms a "slump" in the screw head.

• Fly cutter: This one is often used to cut circles in wood and other soft metals. The diameter of circles may be adjusted by changing the cutter blade setting.

• Hole saw: It cut holes from one to six centimeters in diameter and has a center bit for directing the cutting blade edge of the saw.

• Reamer bit: The tapered bit of reamer may be used on existing holes rather than to enlarge holes.

• Screw pilot bit: This beautiful bit is used for drilling body holes. A pilot hole is used along with the countersink.

• Wire Brushes: It use to remove rust and to clean up metal and is available either as a wheel or a cup with wire brush.

• Plastic bit: This is designed with a tip so as to prevent splintering when drilling plastic. It is important to reduce the speed and slowly drill the other side of the plastic.

• Plug cutter: Use this to remove cylindrical shapes from the wood. It covers the screw using a small cylindrical plug.

Liquefaction Mitigation by Deep Soil Mixing Method (DSM)

Deep soil mixing (DSM) is an effective and versatile method of preventing damage caused by soil liquefaction. Liquefaction is the weakening and subsequent instability of soils caused by applications of force such as seismic activity, erosion, construction, or excessive load bearing. Significant movement shifts the underlying soils, allowing groundwater to rise and fill the spaces created by the movement. This release of water weakens the composition of otherwise stable soil. Soil can also become saturated and unstable through industrial dumping or by leakage from faulty retaining structures.

Too Much Moisture Creates Big Problems

When the soil contains too much water, it can fail to provide support for building foundations, causing them to shift, crack or even collapse. It can also render some geographical areas unsuitable for building by creating soil that is too wet and soft to allow safe construction. Not only is the soil too unstable to support the significant weight of new building construction, it can render existing buildings unsafe. Failure to contain liquid soils can result in seepage of toxic or noxious substances (chemicals, sewage or other waste products).

Deep Soil Mixing Can Solve Liquefaction Issues

An effective way to conduct Soil liquefaction mitigation is through seep soil mixing (DSM). The DSM method involves boring through the soil with a specialized, large-diameter auger (between three and 12 feet) equipped with mixing paddles. Once the auger reaches the appropriate depth, it is filled with cement that is released through holes on the core of the auger. As the cement fills the hole, the mixing paddles combine it with the surrounding soil to create a solidified, underground column.

In addition to its uses in building construction, DSM is also utilized in projects that require sludge stabilization such as Brownfield redevelopment and industrial cleanup. In these cases, DSM technicians can use soil reagents such as fly ash or harder, less porous soil types to reduce the moisture level of the sludge.

DSM can also be used for chemical remediation. By solidifying contaminated soil with either cement or other binders, the contaminants in the soil are isolated and solidified, preventing them from seeping into nearby water supplies. New developments include the use of zero-valent iron, carbon and special clays to create solid soils and reduce the impact of liquefaction. Traditional cement columns and solidifying agents are both effective methods of barrier construction to protect environmentally sensitive areas from infiltration, or to stabilize areas prone to soil erosion

Foundation Repair - Your Underpinning Options

When it comes to foundation repairs and your home, there are several choices that need to be made. These choices range from using helical piers or steel push piers, waterproofing or underpinning, concrete segmented piles or steel push piers or even eccentric vs. concentric piers. You will hear proponents for each different type of foundation repair underpinning system, you will also hear many different reasons why some steel push piers are better than other steel push piers. Wading through all of this information is the key to finding the right method and means of repairing your home. Here we will focus on the differences in piering systems, specifically eccentric piers verses concentric piers. First we must define the terms eccentric and concentric. An eccentric piering systems is one who’s pile axis is not in line with its applied load. A concentric pier is a pier bracket and pile who’s axis is in line with the applied load. 

Next, you must categorize these piering systems.

                      Eccentric Piers                             Concentric Piers        

                      Steel Push Piers                             Steel Push Piers       

                      Helical Piers                            Segmented Concrete Piers       

                      Micro Piers                                      Hybrid Piers

For foundation repair applications, helical piers are always eccentric in nature. The helical sections are installed through the bracketing system from the side of the pier. Micropiers are also installed through the bracketing systems from the side of the pier. The major reason for this is the relatively large equipment used to install these types of systems cannot fit below the wall or footing. 

Segmented Concrete Piles are installed directly below the footing and then a bracket or platform is installed on top of the pile to transfer the applied load to the pier. Hybrid piers are the latest concept in underpinning products. These pier systems generally use concrete filled steel pier sections installed directly below the footing and then either a steel bracket or concrete block is placed on top to transfer the load to the pier. These hybrid piers are marketed as the best of both worlds, in reality they are compromise of both worlds. They do not provide the full benefits of steel piers and they have the same negatives as the segmented concrete piles. 

As noted above, steel push piers can be eccentric or concentric in nature. Each manufacturer generally determines which design best fits their manufacturing and design capabilities and sticks with that style. Only Earth Contact Products has successfully designed and engineered both types of systems for residential use. 

What is better, eccentric or concentric? Well that is the $64,000 question. There is no real answer, because both, if designed properly and applied properly, will work well. While an eccentric designed pier requires more engineering and tighter quality control, not only can they work well but some have worked well for over 30 years. This is not to say all eccentric piers have good engineering behind them. Many are manufactured around cost constraints opposed to good engineering. Concentric steel piers are a lower tech solution that has many application advantages over its rival, the eccentric pier. They can be installed with less footing modification, they can be installed in lower headroom areas and they require less installation equipment to use. 

Concentric piers are great for crawl spaces due to the fact that a tall drive stand is not needed to drive the pier sections. For eccentric piers to be used in a crawl space you will need either a fairly deep crawl space or you will have to cut through the flooring to make room for the drive stand. Concentric piers are also not affected by deep brick ledges or other obstacles like their competition. 

The down side to most concentric piers is in their lifting or stabilization of structures. Most concentric piers do not allow room for anything more than a bottle jack (car jack) for lifting. They are pressured up with the bottle jack and then simple shims are placed between the bracketing system and the footing, the footing is then lowered onto the pier system. Bottle jacks are very undesirable for a couple of reasons. First, the structure is over lifted to allow for the steel shims (similar to segmented concrete piles). Next, with bottle jacks, the installer has no way to measure or control the hydraulic pressure applied to the structure. Most engineers frown on the use of bottle jacks for structural repairs. 

There is only one concentric pier available, that uses a hydraulic manifold lifting system and is continuously adjustable, on the market today. The Earth Contact Products Model 200 uses a hydraulic manifold system, the same system used on their eccentric push piers. This system was designed by engineers for engineers to allow for critical infinite adjustability and control in lifting structures. The Model 200 also uses a patented adjusting platform that does not require over lifting or shims. This unique combination has created large demand and acceptance of this particular concentric piering system. 

As you can see there are many variables and styles of underpinning pier systems available. So how do you choose the one that is right for your home? This is the easy part. First, hire an engineer and let him help determine your foundation repair needs. Then take your new found knowledge out into the market and wade through the variety of foundation repair contractors and find one that installs a quality piering system that has been designed and engineered to perform on your home. No bottle jacks, no shims, no shallow installation methods, just good engineering and manufacturing by a quality foundation repair company. Now, whether you are in Dallas, Texas, Kansas City, Kansas or Columbus, Ohio get out there and get your home fixed correctly and permanently. 

Slurry Walls and Soil Mixing give Construction Solid Ground

Slurry Wall Construction and Deep Soil Mixing are Important Parts of Construction

Many don’t realize it, but construction is a complicated process. People think construction projects take too long because people are not working hard. This couldn’t be further from the truth. One of the reasons certain construction projects take so long is because of the ground improvement which needs to take place. It isn’t a good idea to try to build something on ground which isn’t properly prepared to bear the weight of a structure. One key process is making sure that groundwater is kept out of the area to keep the ground from becoming saturated and shifting.

Bentonite Slurry Walls Help Establish a Barrier against Groundwater

One way to do this is with slurry wall construction. Slurry walls are usually a combination of bentonite and water inside a trough. Bentonite is an absorbent clay which increases the viscosity of the solution, so the slurry is thicker than water. The slurry exerts an outward force which counteracts the force on the outside of the trench. The slurry wall can hold as a temporary barrier until it isn’t needed anymore, or it can be replaced with concrete. Regardless of the use, the slurry is collected and recycled when it isn’t needed. This means that there is very little waste involved in this process.

Dropping Anchors with Deep Soil Mixing

Another procedure used to establish solid foundations during construction is soil mixing. There are several varieties of soil mixing, including deep soil mixing, shallow soil mixing, and backhoe stabilization. All procedures use similar processes though. A large auger (one to four yards across) is drilled into the ground while fluid grout is pumped through the center of the auger. After reaching the proper depth the auger is removed and the solution dries. This creates a solid, stable anchor pillar in the ground. These anchors are used as elements to the building contraction, or a solid point to position heavy machinery on top of.

The Critical first step of Construction

These two processes are extremely important and common in construction projects. They both require state of the art machinery and qualified technicians to be completed properly. So the next time there is a construction site which seems to be stuck in the preliminary stages, consider all the preparation work which has to be done before the plans can get “off the ground”.

Water Jet Cutter

 In the 1950s, forestry engineer Norman Franz experimented with an early form of water jet cutter to cut lumber. However, the technology did not advance notably until the 1970s when Mohamed Hashish created a technique to add abrasives to the water jet cutter. Today the water jet is unparalleled in many aspects of cutting and has changed the way many products are manufactured. Many types of water jets exist today, including plain water jets, abrasive water jets, percussive water jets, cavitation jets and hybrid jets.

Operation

The cutter is commonly connected to a high-pressure water pump where the water is then ejected from the nozzle, cutting through the material by spraying it with the jet of high-speed water. Additives in the form of suspended grit or other abrasives, such as garnet and aluminum oxide, can assist in this process.

Benefits

An important benefit of the water jet cutter is the ability to cut material without interfering with the material's inherent structure as there is no "heat-affected zone" or HAZ. Minimizing the effects of heat allows metals to be cut without harming or changing intrinsic properties.

Water jet cutters are also capable of producing rather intricate cuts in material. The kerf, or width, of the cut can be changed by changing parts in the nozzle, as well as the type and size of abrasive. Typical abrasive cuts are made with a kerf in the range of 0.04" to 0.05" (1.016 to 1.27 mm), but can be as narrow as 0.02" (0.508 mm). Non-abrasive cuts are normally 0.007" to 0.013" (0.178 to 0.33 mm), but can be as small as 0.003" (0.076 mm), which is approximately the size of a human hair. These small cutters can make very small detail possible in a wide range of applications.

Water jet is considered a "green" technology. Water jets produce no hazardous waste, reducing waste disposal costs. They can cut off large pieces of reusable scrap material that might have been lost using traditional cutting methods. Parts can be closely nested to maximize material use, and the water jet saves material by creating very little kerf. Water jets use very little water (a half gallon to approximately one gallon per minute depending on cutting head orifice size), and the water that is used can be recycled using a closed-looped system. Waste water usually is clean enough to filter and dispose of down a drain. The garnet abrasive is a non-toxic natural substance that can be recycled for repeated use. Garnet usually can be disposed of in a landfill. Water jets also eliminate airborne dust particles, smoke, fumes, and contaminates from cutting materials such as asbestos and fiberglass. This greatly improves the work environment and reduces problems arising from operator exposure.

Versatility

A water jet cutter creating a specialist tool

Because the nature of the cutting stream can be easily modified the water jet can be used in nearly every industry; there are many different materials that the water jet can cut. Some of them have unique characteristics that require special attention when cutting. Each material cut will have some unique characteristics that have to be taken into account.

Materials commonly cut with a water jet include rubber, foam, plastics, composites, stone, tile, metals, food, paper and much more. Materials that cannot be cut with a water jet are tempered glass, diamonds and certain ceramics.

Water jet cuts are not typically limited by the thickness of the material, and are capable of cutting materials over eighteen inches (45 cm) thick. The penetrating power of these tools has led to the exploration of their use as anti-tank weapons but, due to their short range and the advent of composite armour, research was discontinued.

Availability

Commercial water jet cutting systems are available from manufacturers all over the world, in a range of sizes, and with water pumps capable of a range of pressures. Typical water jet cutting machines have a working envelope as small as a few square feet, or up to hundreds of square feet. Ultra-high pressure water pumps are available from as low as 40,000 psi (276 MPa) up to 90,000 psi (621 MPa).

Process

There are six main process characteristics to water jet cutting:

Uses a high velocity stream of abrasive particles suspended in a stream of Ultra High Pressure Water (30,000 - 90,000 psi) which is produced by a water jet intensifier pump.

Is used for machining a large array of materials, including heat-sensitive, delicate or very hard materials.

Produces no heat damage to workpiece surface or edges.

Nozzles are typically made of sintered boride.

Produces a taper of less than 1 degree on most cuts, which can be reduced or eliminated entirely by slowing down the cut process.

Distance of nozzle from workpiece affects the size of the kerf and the removal rate of material. Typical distance is .125".

Temperature is not as much of a factor.

Edge quality

Edge quality for water jet cut parts is defined with the numbers 1 through 5. Lower numbers indicate rougher edge finish; higher numbers are smoother. For thin materials, the difference in cutting speed for Quality 1 could be as much as 3 times faster than the speed for Quality 5. For thicker materials, Quality 1 could be 6 times faster than Quality 5. For example, 4 thick Aluminum Q5 would be 0.72 ipm (18 mm/min) and Q1 would be 4.2 ipm (107 mm/min), 5.8 times faster.

Multi-axis cutting

Main article: Multiaxis machining

A 5-Axis Waterjet Cutting Head

A 5-Axis Waterjet Part

With recent advances in control and motion technology, 5-axis water jet cutting (abrasive and pure) has become a reality. Where the normal axes on a water jet are named X (back/forth), Y(left/right) and Z (up/down), a 5-axis system will typically add an A axis (angle from perpendicular) and C axes (rotation around the Z-axis). Depending on the cutting head, the maximum cutting angle for the A axis can be anywhere from 55, 60, or in some cases even 90 degrees from vertical. As such, 5-axis cutting opens up a wide range of applications that can be machined on a water jet cutting machine.

A 5-axis cutting head can be used to cut 4-axis parts, where the bottom surface geometries are shifted a certain amount to produce the appropriate angle and the Z-axis remains at one height. This can be useful for applications like weld preparation where a bevel angle needs to be cut on all sides of a part that will later be welded, or for taper compensation purposes where the kerf angle is transferred to the waste material - thus eliminating the taper commonly found on water jet-cut parts. A 5-axis head can cut parts where the Z-axis is also moving along with all the other axis. This full 5-axis cutting could be used for cutting contours on various surfaces of formed parts.

Because of the angles that can be cut, part programs may need to have additional cuts to free the part from the sheet. Attempting to slide a complex part at a severe angle from a plate can be difficult without appropriate relief cuts.

Removal of Asbestos Garages or Corrugated Asbestos Roofing Sheets

There is a common misconception that only a licensed removal agency or local authority can remove your tired asbestos garage.  

If you are contemplating replacement of your present prefabricated garage then it is very likely that this building contains asbestos cement or Chrysotile (‘white asbestos’). Asbestos cement normally contains from about 5% of white asbestos by weight.

Asbestos is a naturally occurring mineral which was used within the concrete garage sector up until the late 1980s. Modern concrete garages no longer contain asbestos within their roof structure preferring to use reinforced cement fibre. Neither material can be identified by any markings and only chemical analysis will prove that asbestos is present.

The mere presence of asbestos does not necessarily create a health risk and the removal of asbestos cement sheets is not governed by any regulatory body although it is strongly recommended that you/your appointed contractors adheres to safe working methods.

• Thoroughly douse the material before starting work. You are advised to introduce a suitable wetting agent such as washing-up liquid, into the water before saturation. 
• Operatives are recommended to wear RPE/PPE (Respiratory/Personal Protective Equipment) to protect from inhalation of dust particles.
• Avoid breaking asbestos panels unnecessarily but if this is necessary continue to wet down the area that you are working.

Borehole drilling

The true definition of borehole drilling is, a deep hole drilled into the ground to extract natural water resources. The majority of UK homes do not have their own water supply, meaning it is mandatory to pay water companies for the privilege of using the water that they supply to us. However it is possible to have your own water supply meaning a minimisation of costs for water use.

With the cost of water use rising and set to rise further, many businesses worldwide are beginning to think of new ways of accessing water. The worldwide water supply is dwindling and as a result of this, water companies will have to raise the cost of using water due to the fact that water will be seen as a precious commodity. Both business and domestic water users believe it or not can have their own water supply.

Borehole drilling companies offer a way of accessing fresh water direct from the earth's core for business or domestic use.  Many countries such as Ghana in West Africa are using this method and as a result are saving significant amounts when it comes to water costs. Borehole drilling makes it possible to create water pumps and water wells for the supply of fresh clean water, eliminating the need to purchase spring or mineral water as well as taking away the need to boil or filter water. This alone is an instant money saver.

Agricultural businesses such as farms vegetable and fruit producers can benefit from having their own water supply. Many people especially domestic home owners might be sceptical or hesitant to create their own water supply because of the initial outlay. However the initial outlay could be considered an investment in future savings. Some may not see the benefits of borehole drilling, however it is worth noting that some borehole drilling companies have reported that customers have recovered the initial monetary spend within a matter of months. The more water used, the more money saved, seems to be the mantra. Businesses will be more likely to make massive savings. Having said this though domestic users can still make significant savings when it comes to water bills.

Borehole drilling is not as widespread as it could be, although many borehole drilling companies have been running for decades catering mainly for the business market. Domestic users are slowly beginning to see the money saving potential of having their own water supply. Especially with the facts in hand, that within the next few years many domestic users are going to see a 30 percent rise in their overall water bills.

HORIZONTAL ASSEMBLIES FOR FIRE-RESISTANCE

A horizontal assembly refers to roofs and floors. Floor and roof assemblies that are required to have a fire-resistance rating must comply with this section. All floor and roof assemblies must be made of materials allowed by the type of building construction and the fire-resistance rating of floor and roof assemblies cannot be less than that required by the building type of construction. But what if you have floor assemblies that separate mixed occupancies?In cases such as this, the assembly must have a fire-resistance rating of no less than the minimum required by code, based on the occupancies that are being separated.

If a floor assembly separates a single occupancy into different fire areas, the assembly must have a fire-resistance rating of no less than what was discussed earlier in this chapter. All floor assemblies that separate living spaces in the same building or sleeping units in occupancies in Group R-1, hotel occupancies, R-2, and I-1 must be a minimum of one-hour fire-resistance- rated construction. The only exception to this is dwelling and sleeping units that are used as separation in buildings of Type IIB, IIIB, and VB construction which must have a fire-resistance rating of no less than ½ hour in buildings that are equipped throughout with an automatic sprinkler system.

Pressure relief valve

A pressure relief valve is a safety device that relieves in case of overpressure in a vessel or piping. The generic terms are pressure relief valve (PRV) or pressure safety valve (PSV).

Main types of pressure relief valves include:


Relief valve (RV) automatic system that relief by static pressure on a liquid. It specifically open proportionally with pressure increasing.

Safety valve (SV) automatic system that relieve static pressure on a gas. It specifically opens almost straight to full lift after a pop sound.

Safety relief valve (SRV) automatic system that relief by static pressure on both gas and liquid.

Pilot operated safety relief valve (POSRV) automatic system that relief by remote command from a pilot on which the static pressure (from equipment to protect) is connected.

Low pressure safety valve (LPSV) automatic system that relief by static pressure on a gas. The pressure is small and near the atmospheric pressure.

Vacuum pressure safety valve (VPSV) automatic system that relief by static pressure on a gas. The pressure is small, negative and near the atmospheric pressure.

Low and vacuum pressure safety valve (LVPSV) automatic system that relief by static pressure on a gas. The pressure is small, negative or positive and near the atmospheric pressure.

RV, SV and SRV are spring operated (even said spring loaded). LPSV and VPSV are spring operated or weight loaded.

Legal and code requirements in industry

In most countries, industries are legally required to protect pressure vessels and other equipment by using relief valves. Also in most countries, equipment design codes such as those provided by the ASME, API and other organizations like ISO (ISO 4126) must be compliant with and those codes include design standards for relief valves.

The main standards, laws or directives are:


ASME (American Society of Mechanical Engineers) Boiler & Pressure Vessel Code, Section VIII, Division 1

API (American Petroleum Institute) Recommended Practice 520 - Sizing, Selection, and Installation of Pressure-Relieving Devices in Refineries: Part I - Sizing and Selection

API Standard 521 - Pressure-relieving and Depressuring Systems

API Standard 526

API Standard 527

ISO 4126

ISO 23251 - Petroleum, petrochemical and natural gas industries - Pressure-relieving and depressuring systems

AD Merckblatt


PED 97/23/EC (Pressure Equipment Directive)

How Zinc Protects Metals And How It Is Applied

Zinc plating prevents decay of the metal by forming a physical barrier on metal and by acting as a barrier if this barrier is damaged. Zinc coatings provide the most effective way of protecting steel against corrosion. Zinc reacts with oxygen to form zinc oxide that further reacts with water molecules in the air to form zinc hydroxide. Finally zinc hydroxide reacts with carbon dioxide in the atmosphere to yield a thin, impermeable, firm and quite insoluble dull grey layer of zinc carbonate which protects it from further corrosion.

How Zinc Protects

When left unprotected, steel will decay in almost any environment. Zinc coatings stop corrosion by providing two protections,namely a physical barrier and cathodic action.

Barrier Protection

Zinc coatings provide a continuous, impervious metallic barrier that does not allow moisture to contact steel. Without direct moisture contact, there is no corrosion.

Cathodic Protection

Another outstanding protection is zinc’s remarkable ability to galvanic ally protect steel. When bare steel is exposed to moisture, such as at a cut edge or surface scratch, steel is protected by the sacrificial loss of zinc in the surroundings of the exposed steel. In the immediate presence of zinc, steel will not corrode until all the zinc has been sacrificed. This is particularly important for coated steel sheet since corrosion will continually undercut both aluminum or paint barrier coatings. The presence of zinc is the key to cathodic protection.

The bond between the zinc and steel is metallurgical so that a coil of zinc coated steel can be cut, punched and formed without damaging the zinc coating.

Zinc Plated Metals

Zinc Plated metal is often used in the construction of warships, such as carriers and submarines. The water and salt repellent qualities of the steel with its solid zinc coating make it the ideal material to use for hulls. It is also used for building structures that will remain strong for many decades. Zinc Plated steel is an ideal material for a multitude of building applications. In the residential construction market, Zinc plated steel has particular and cost-effective applications in framing, roofing, and rain ware, heating or cooling and venting and household appliances.

How Zinc are Applied

There are two processes namely hot dip and electro galvanized to apply Zinc. Hot dip plating put a thick robust layer that is necessary for the protection of the underlying metal. This is the case in automobile bodies, where additional rust proofing paint will be applied. The protection of steel from corrosion by the hot dip zinc galvanizing has been practiced for almost 200 years, and the technique is still unequaled for the long term protection.

A thinner form of plating is applied by electroplating, called "electro galvanization". However, the protection this process provides is insufficient for products that will be constantly exposed to acidic materials such as salt water. Most nails made today are electro-galvanized.

Galvanized metal has made it possible for humanity to enjoy long lasting shelters, as well as explore the ocean and the ocean floor in perfect safety. For over a century, zinc has enhanced the longevity and performance of steel. There is no doubt that humankind will continue to find ways to utilize this valuable construction tool in new and exciting ways in the years to come.