All About Diamond Drilling Equipments

Diamond is the hardest naturally formed mineral found on earth. It is used not only for making expensive and beautiful jewelry but also for making drilling equipments. Since diamonds are very hard, they are ideal for making cutting and grinding equipments. Diamonds can be used to cut, drill, grind and polish. Thus it is greatly used in various industrial applications. Some of the common equipments used are the diamond tipped drill bit and the saw blades. Diamond powder is used as an abrasive in industries. The diamonds used for these purposes are of lesser quality and are called ‘bort’. Thus, there are two grades of diamonds - the gem grade diamond and the industrial grade diamond. The industrial grade diamonds should be hard and have heat conductivity.

The demand for diamonds is greater than the supply, so the diamond drill is very expensive. Although, there are a number of types of drills, the diamond drill is a very essential piece of equipment in an industry that needs to do a lot of drilling. The diamond drill is actually a drill with the diamond drill bit attached to the end of hollow drill rods. The diamonds used are fine to micro fine diamonds. To keep the sharpness and hardness of the diamond drill, it is necessary to give it sufficient lubrication and cooling. The holes made are very clean and giving the best results. The drilling has to be done slowly so that the life of the drill bits can be extended for a longer period of time. Drilling is a laborious process. It is also a tiring and demanding task and uses up a lot of physical energy. But, it needs to be done.

The diamonds drills can make holes in any type of substance, right from a soft one to a hard one. It includes bricks, metals, concrete and any other material without giving out much noise. The holes can be made quickly without any vibrations and much effort, since the drill is made of hard diamond. The diamond drilling equipments are long lasting and penetrate fast to drill a hole.

The diamond drilling equipments are used in all kinds of industrial applications. We are generally not aware of it many uses. They are used by the construction industry for making holes in bricks, concrete and iron. It is used in the mining industry to drill holes at places where there are mines. Wherever holes have to be made for placing cables, where anchoring bolts have to be placed and also where load carrying machines have to be installed, the diamond drilling equipments are used.

There are two types of drilling techniques. The dry drilling technique is used when concrete, hard surfaces, pavements, bricks or any hard surface has to be drilled. The wet drilling technique is used when the place that has to be drilled is fully under water.

The diamond drilling equipments are of different types. Synthetic diamonds are used in the impregnated bit’s matrix series. The matrix layer has the diamonds in a powdered metal bond. They have a long life and also penetrate fast. They are used in many forms of drilling. Surface set diamond bits have a single natural diamond layer. They have a hard matrix compound on the face of the bit. They are used while drilling soft to medium hard surfaces.

Diamond reaming shell has natural or synthetic diamonds. It is used to attach the drill bit to the core barrel. The main work of the reaming shell to make a hole that is exact in diameter for the core barrel to go through, having enough space for a new drill bit, when the old one has to be changed. Long diamond reaming shells are also available for drilling purposes.

Diamond core bits are thing walled core bits that are used in a large number of applications. They are used to drill holes in are concrete, glass, ceramics and also in all kinds of pipes used in electricity, drainage etc. Wet cut drill core bits and dry cut drill core bits are available for various purposes.

Synthetic diamond polycrystalline is also used in making drilling equipments. They are used in making drill bits, reaming shells, saw blades etc. Polycrystalline diamond pads or cutters (PDC) are placed in rows of polycrystalline diamonds kept on tungsten carbide substrate on the bit face, to drill holes in areas that are too sticky or soft. You have PDC core bits and PDC drill bits which are cost effective and very useful in drilling and cutting activities.

The diamond drilling equipments are no doubt expensive, but they are very effective in making clean holes that are necessary for all construction, mining and power, drainage, gas lines purposes. We should check out the various companies that manufacture these equipments, obtain details about the equipments and the price and then order the equipment that we need. The internet would be the best place to gather all the information.

Hammer Drills and Impact Drills and Their Differences

There are many differences in a lot of different power tools. Two tools that everybody loves are Hammer Drills and Impact Drills. These drills are used for different reasons. Both have there pros and cons in there usages. Hammer drills have more power to it as an impact drill will provide you with more torque.

People use these drills for all different reasons. Depending on the manufacture that your drill is from you are able to get a drill in all different sizes and speeds and torque. A lot of drills are no capable to be battery powered as opposed to plugging them into the outlets. There are a few different voltages. They range from 12 volt up to 120 volts. There are many brand names that you can choose form. The list starts with DeWalt, Hilti, Hitachi, Milwaukee, and Makiti. They all have there differences between each manufacture and the differences between hammer drills and impact drills are not so common to always see.



When using a Hammer Drill it is important that you use the one that will get your job done correctly. There are so many different reasons to use a hammer drill. Whether you are just drilling in to the wall or if you are drilling into the ground there is always a hammer drill that will fit your needs. Its important that when looking for a drill you take a look at your job requirements and see what type of job it will be.

A lot of drills are capable to provide you to use any size drill bits that will get you hole to the adequate size. There are safety precautions that you will need to know before you manually use these power tools. Authorized personal only.

Now as far as Impact Drills are concerned they have a lot of different qualities that will help you attack any type of job you are looking to pursue. From small to large you are able to use a variety of different brand name impact drills and drivers. People now use impact drills as there new screw driver. It's more convenient to use an impact drill/driver as opposed the the old school hand screw driver.

The reasoning there is that you are not straining your hand or wrist when tightening a screw. The impact drill provides an easier way for you to do what you need to do whether the job is on a construction job site or just simply tightening the loose screw to your toilet paper rack. It is very easy to use and that is why people are turning to power tools now a days because they are more equipped for the ordinary user and installer. Impact drills also are able to insert different drill bits and spade bits so that you can attack any drilling need that you need to have done.

Fibreglass Moulds

Fibreglass moulds are required for the production of fibreglass mouldings, but suppose you wanted to design and manufacture a boat hull, you would need to make a pattern also known as a plug or buck first, this is an exact model/replica of the end product, the pattern will have the exact dimensions and surface appearance of the finished product.

Fibreglass moulds are required for the production of fibreglass mouldings, but suppose you wanted to design and manufacture a boat hull, you would need to make a pattern also known as a plug or buck first, this is an exact model/replica of the end product, the pattern will have the exact dimensions and surface appearance of the finished product.

Once the pattern is made, it is prepared with several coats of mould release wax followed by a coat of PVA release agent, the pattern is now ready for the gel-coat to be applied, this will be painted or sprayed on depending upon the size of the mould to be made, but the gel-coat should be a tooling grade material and as such provide a long life for the production mould and good gloss retention, once the gel-coat has cured a second coat is applied and allowed to cure as well, the gel-coat will remain tacky, that is ok, the tacky surface of gel-coat will enable a good bond to the laminate to be achieved in the next process.

Now the gel-coat has cured but still a little tacky, the first layer of glass fibre is laid onto the back of the gel-coat and impregnated with resin, the saturated glass fibre is then rolled with a special roller to remove trapped air and consolidate the glass fibres, this initial layer is allowed to harden and cure, we call this process the first layer or skinning the mould, now the first layer has cured you can apply more layer of glass fibre impregnated with resin until the required thickness is achieved, these consecutive layers are also allowed to harden and cure, once these new laminates have cured the mould can be stabilised with either a timber or metal frame-work which is bonded to the back of the mould to keep it rigid and stable, but remember a mould can also be more than one piece, depending upon the design of the product (complexity of design , undercuts, flash line, ect) but if the mould is flanged into multiple pieces, you must ensure that locators are employed on all flanges to ensure all mould pieces align.

Now the mould is complete the pattern can be released, compressed air or wedges may be required to break the seal, once the pattern is released from the mould we start again by applying several coats of mould release wax to the new mould, remember its good practice to apply PVA release agent to the mould face of the new mould for the first pull, this will ensure that the first fibreglass product will come out with out sticking.

Also fibreglass moulds are manufactured for moulding products in pre-cast concrete, these moulds are called pre-cast concrete moulds, and are used to produce paving slabs, sea-defence sections and components that are to intricate for the mould to be formed in timber, in short fibreglass moulds come in all shapes and sizes and are used to manufacture products for a wide range of applications in industry, some of these products range from,

Boat hulls and associated components, water slides and theme park rides, architectural columns and arch's, Lorry wind deflectors and body kits, airport furniture, pre-cast concrete moulds, wind turbine blades, planters, enclosures, shower trays and baths, modular buildings, machine guards and covers, and so much more...

Congratulations, you now have a brief understanding of fibreglass moulds, and the process's employed to manufacture a basic mould, but you must also be mindful of material choice and mould design, as discussed before, some moulds will need to be more then one piece and hence need to be flanged into multiple pieces, so design criteria at the product stage is key, but don't be put off by this, fibreglass is a great composite material that allows designers the scope to achieve products that are stunning and cost effective. 

ALLOWABLE LOAD-BEARING VALUES OF SOILS(IBC 09)

There are maximum allowances that you must adhere to for foundation pressure, lateral pressure, or lateral sliding-resistance values. These must not exceed the values allowed by code unless you have data to verify the use of a higher value. Any higher values must be submitted and approved for use.

Do not assume that mud, organic silt, organic clays, peat, or unprepared fill have an acceptable load-bearing capacity unless you have the data to back that up. I believe we all know what happens when we assume something to be true. And it would be a great deal of time, money, and energy wasted if you assume that the use of a material is acceptable without the data to back it up. That being said, there is however, an exception to this. An acceptable load-bearing capacity is permitted to be used if the building official considers the load-bearing capacity of mud, organic silt, or unprepared fill to be adequate for the support of lightweight and temporary structures.

Presumptive load-bearing values of foundation materials :

Class of materials	Load-bearing pressure (Pounds per square foot)
Crystalline bedrock	12,000
Sedimentary and foliated rock	4,000
Sandy gravel and/or gravel (GW and GP)	3,000
Sand, silty sand, clayey sand, silty gravel and clayey gravel (SW, SP, SM, SC, GM and GC)	2,000
Clay, sandy clay, silty clay, clayey silt, silt and sandy silt (CI, ML, MH and CH)	1,500

***Where the building official determines that in-place soils with an allowable bearing capacity of less than 1,500psf are likely to be present at the site, the allowable bearing capacity shall be determined by a soils investigation.

To determine the resistance of structural walls to lateral sliding, calculate by combining the values from the lateral bearing and sliding resistance. Remember you have to submit the reasons or data for this and obtain approval. In the case of clays, such as sandy, silty, or clayey silt, under no circumstance can the lateral sliding resistance be more than one-half of the dead load. It is possible for increases to be allowed for lateral sliding resistance. For each additional foot of depth to a maximum of 15 times the tabular value.

Earthquake Resistant Buildings in Seismic Zones of India

Earthquakes occur due to movements along faults that have evolved through geological and tectonic processes. Often they occur without any prior warning and are, therefore, unpredictable. The large area of India is prone to earthquake. The construction of earthquake resistant building is the only solution for safeguarding our urban centres from the menace of earthquakes.

The natural disasters like earthquake can not be prevented, but measures are required to be taken to reduce the extent of damage, especially in a vast country like India which is the 2nd largest populated country of the world supported by low level infrastructure and inadequate resources. High levels of risk combined with low levels of coping mechanisms result in major disruptions or loss of lives and livelihood.

High-rise building in Mumbai

The developed countries of the world are adopting new technique of construction of seismic proof buildings whereas under developed countries do not give much attention for the construction of seismic proof buildings due to shortage of resources. With the result world’s worst disasters always take place in underdeveloped and poor countries. Disasters cause enormous destruction and human sufferings. The losses due to occurrence of earthquakes reduce the pace of economic development and often lead to depletion of available resources.

Recommendations :

The earthquake disasters can be averted with the construction of seismic proof buildings. Each building can be designed in such a way that it may withstand during severest quakes depending on the seismic zone it falls in. “The National Disaster Management Authority” (NDMA) has made it compulsory for all new constructions to be earthquake-resistant, especially in cities located in seismic zones. The guidelines have also recommended selective seismic strengthening and retrofitting of existing priority structures located in high-risk areas.

It has also been proven that well maintained buildings have faired better than those in poor condition during and after an earthquake. Thus, maintenance and seismic retrofit are two critical components for the protection of historic buildings in areas of seismic activity. It makes no sense to retrofit a building without improvements. The subcontinent is sitting on the highly seismic Indian plate, with some major faults lines. In fact there is no seismically safe zone in India. Disasters have left the 800-year-old Qutub Minar with a slight tilt but it has survived several quakes in its lifetime.

 • Implementation of Disaster Management Plan

Earthquake-Proof Skyscrapers in San Francisco

The Disaster Management Bill, likely to be presented in the winter session of Parliament, will make it necessary for all states to have a disaster management authority and implement the national disaster plan. "Eventually disaster management is a state’s concern and the action plan has ultimately depend upon the state’s own concerns and ability to set up institutional and financial.

• Creation of Special Force At National Level
At the national level, other measures are being planned. Eight battalions of 10,000 soldiers are being trained for being posted to eight different locations and money has also been sanctioned for buying aircraft for their use in cases of emergency.

• Creation of Emergency Operation Centre
It is being equipped with state-of-the-art communication links and micro-zonation of 38 cities above 10-lakh population is being attempted in different phases. The micro-zonation of Delhi has just been completed.

Earthquake Destruction

In words of Science and Technology Minister Kapil Sibal, the micro-zonation process is the government’s effort to take effective measures with proper research to minimize risk to existing buildings in the event of an earthquake. Micro-zonation, he says, will help bring area-wise changes in building bylaws to ensure quake resistant measures in the structural designs of high rises to minimize the risk of heavy damage and loss of life in event of an earthquake.

While the government is attempting a paradigm shift in the disaster management from relief and rehabilitation to mitigation and prevention, to make it successful will eventually depend upon the civil society.

Mud Density and Its Importances for The Drilling Operation

Mud weight or mud density is one of the important drilling fluid properties because it balances and controls formation pressure. Moreover, it also helps wellbore stability. Weight of drilling mud is measured and reported in pounds per gallon (PPG), pound per cubic feet (lb/cu.ft), or grams per milliliter (b/ml).

Mud density is normally measured by a conventional mud balance; however, if you have some air inside a fluid phase, reading from the conventional mud balance will give you an inaccurate number. Therefore, the most accurate method to measure the mud weight is with a pressurized mud balance.

The pressurized mud balance looks like the convention one, but it has a pressurized sample cup. When you press mud sample in the cup, any gas in fluid phase is compressed to very small volume so the mud weight measurement is more accurate.

What will be happened if there is insufficient drilling fluid density?
1. Well control - The well will be in an under balance condition so any formation fluids - gas, oil, and water- will enter into the wellbore.

2. Wellbore collapse (wellbore instability) - the wellbore will possibly become unstable, if the hydrostatic pressure provided by a mud column is below formation pressure.

What will be happened if the mud weight is too high?

1. Lost circulation - If the hydrostatic pressure from mud column exceeds formation strength, it will cause formation to break. Once the formation is broken, the drilling fluids will lose into the induced formation fractures.

2. Decrease in rate of penetration - The more density you have while drilling, the less ROP will be. Practically, while drilling, low mud weight is used at the beginning and weight will be increased as the well is drilled deeper in order to optimize ROP.

3. Stuck pipe - Since there are differences between the formation pressure and the hydrostatic pressure, there will be a lot of chances that a drill string will get differentially stuck across permeable rocks.

4. Formation damage - The more mud weight is in the well, the more mud filtration invades into porous formations. The invaded mud will cause damage to formation rocks. 

Ductile iron pipe

Dimensions   Ductile iron pipe is sized according to a dimensionless term known as the Pipe Size or Nominal Diameter (known by its French abbreviation, DN). This is roughly equivalent to the pipe's internal diameter in inches or millimeters. However, it is the external diameter of the pipe that is kept constant between changes in wall thickness, in order to maintain compatibility in joints and fittings, and consequently the internal diameter does vary, sometimes significantly, from its nominal size. Nominal pipe sizes vary from 3 inches up to 64 inches, in increments of at least 1 inch, in the USA. Pipe dimensions are standardised to the mutually incompatible AWWA C151 (U.S. Customary Units) in the USA, ISO 2531 / EN 545/598 (metric) in Europe, and AS/NZS 2280 (metric) in Australia and New Zealand. Although both metric, European and Australian are not compatible and pipes of identical nominal diameters have quite different dimensions.

North America
 Pipe dimensions according to the American AWWA C-151

Pipe Size	Outside Diameter (in)
3	3.96
4	4.8
6	6.9
8	9.05
10	11.1
12	13.2
14	15.3
16	17.4
18	19.5
20	21.6
24	25.8
30	32

Europe

European pipe is standardized to ISO 2531 and its descendent specifications EN 545 (potable water) and EN 598 (sewage). European pipes are sized to approximately match the internal diameter of the pipe, following internal lining, to the nominal diameter. ISO 2531 maintains dimensional compatibility with older German cast iron pipes. Older British pipes, however, which used the incompatible imperial standard, BS 78, require adapter pieces when connecting to newly installed pipe. Coincidentally, the British harmonization with European pipe standards occurred at approximately the same time as its transition to ductile iron, so almost all cast iron pipe is imperial and all ductile pipe is metric.

DN	Outside Diameter [mm (in)]	Wall thickness [mm (in)]
		Class 40	K9	K10
40	56 (2.205)	4.8 (0.189)	6 (0.236)	6 (0.236)
50	66 (2.598)	4.8 (0.189)	6 (0.236)	6 (0.236)
60	77 (3.031)	4.8 (0.189)	6 (0.236)	6 (0.236)
65	82 (3.228)	4.8 (0.189)	6 (0.236)	6 (0.236)
80	98 (3.858)	4.8 (0.189)	6 (0.236)	6 (0.236)
100	118 (4.646)	4.8 (0.189)	6 (0.236)	6 (0.236)
125	144 (5.669)	4.8 (0.189)	6 (0.236)	6 (0.236)
150	170 (6.693)	5 (0.197)	6 (0.236)	6.5 (0.256)
200	222 (8.740)	8.4 (0.331)	6.3 (0.248)	7 (0.276)
250	274 (10.787)	5.8 (0.228)	6.8 (0.268)	7.5 (0.295)
300	326 (12.835)	6.2 (0.244)	7.2 (0.283)	8 (0.315)
350	378 (14.882)	7 (0.276)	7.7 (0.303)	8.5 (0.335)
400	429 (16.890)	7.8 (0.307)	8.1 (0.319)	9 (0.354)
450	480 (18.898)	-	8.6 (0.339)	9.5 (0.374)
500	532 (20.945)	-	9 (0.354)	10 (0.394)
600	635 (25.000)	-	9.9 (0.390)	11.1 (0.437)
700	738 (29.055)	-	10.9 (0.429)	12 (0.472)
800	842 (33.150)	-	11.7 (0.461)	13 (0.512)
900	945 (37.205)	-	12.9 (0.508)	14.1 (0.555)
1000	1,048 (41.260)	-	13.5 (0.531)	15 (0.591)
1100	1,152 (45.354)	-	14.4 (0.567)	16 (0.630)
1200	1,255 (49.409)	-	15.3 (0.602)	17 (0.669)
1400	1,462 (57.559)	-	17.1 (0.673)	19 (0.748)
1500	1,565 (61.614)	-	18 (0.709)	20 (0.787)
1600	1,668 (65.669)	-	18.9 (0.744)	51 (2.008)
1800	1,875 (73.819)	-	20.7 (0.815)	23 (0.906)
2000	2,082 (81.969)	-	22.5 (0.886)	25 (0.984)

Australia

Australian and New Zealand pipes are sized to an independent specification, AS/NZS 2280, that is not compatible with European pipes even though the same nomenclature is used. Australia adopted at an early point the imperial British cast iron pipe standard BS 78, and when this was retired on British adoption of ISO 2531, rather than similarly harmonizing with Europe, Australia opted for a 'soft' conversion from imperial units to metric, published as AS/NSZ 2280, with the physical outer diameters remaining unchanged, allowing continuity of manufacture and backwards compatibility. Therefore the inner diameters of lined pipe differ widely from the nominal diameter, and hydraulic calculations require some knowledge of the pipe standard.

Nominal Size (DN)	Outside Diameter [mm (in)]	Nominal Wall Thickness [mm (in)]		Flange Class
		PN 20	PN 35
100	122 (4.803)	-	5 (0.197)	7.0
150	177 (6.969)	-	5 (0.197)	8.0
200	232 (9.134)	-	5 (0.197)	8.0
225	259 (10.197)	5 (0.197)	5.2 (0.205)	9.0
250	286 (11.260)	5 (0.197)	5.6 (0.220)	9.0
300	345 (13.583)	5 (0.197)	6.3 (0.248)	10.0
375	426 (16.772)	5.1 (0.201)	7.3 (0.287)	10.0
450	507 (19.961)	5.6 (0.220)	8.3 (0.327)	11.0
500	560 (22.047)	6 (0.236)	9 (0.354)	12.0
600	667 (26.260)	6.8 (0.268)	310.3 (0.406)	13.0
750	826 (32.520)	7.9 (0.311)	12.2 (0.480)	15.0

Joints

Individual lengths of ductile iron pipe are joined either by flanges, couplings, or some form of spigot and socket arrangement. 

 
Flanges 

 
Flanges are flat rings around the end of pipes, which mate with an equivalent flange from another pipe, the two being held together by bolts usually passed through holes drilled through the flanges. A deformable gasket, usually elastomeric, placed between raised faces on the mating flanges provides the seal. Flanges are designed to a large number of specifications that differ due to dimensional variations in pipes sizes, and pressure requirements, but also due to independent standards development. In the U.S. flanges are 'threaded' and can be 'welded' onto the pipe. In the European market flanges are often welded on to the pipe. Flanges are available in a standard 125 lb. bolt pattern as well as a 250 lb. bolt pattern (steel bolt pattern). Both are usually rated at 250 PSI. A flanged joint is rigid and can bear both tension and compression as well as a limited degree of shear and bending. It is also dismantlable once constructed. Flanged joints cannot, however, be reliably used for buried pipe due to the possibility of soil movement placing very large bending loads on the joint. 

 
Current flange standards used in the water industry are ANSI B16.1 in the USA, EN 1092 in Europe, and AS/NZS 4087 in Australia and New Zealand. 

 
Spigot and Socket 

Spigot and sockets involve a normal pipe end, the spigot, being inserted into the socket or 'bell' of another pipe or fitting with a seal being made between the two within the socket. Normal spigot and socket joints do not allow direct metal to metal contact with all forces being transmitted through the elastomeric seal. They can consequently flex and allow some degree of rotation, allowing pipes to shift and relieve stresses imposed by soil movement. The corollary is that unrestrained spigot and socket joints transmit essentially no compression or tension along the axis of the pipe and little shear. Any bends, tees or valves therefore require either a restrained joint or, more commonly, thrust blocks, which transmit the forces as compression into the surrounding soil. 

 
A large number of different socket and seals exist. The most modern is the 'push-joint' or 'slip-joint', whereby the socket and rubber seal is designed to allow the pipe spigot to be, after lubrication, simply pushed into the socket. Push joints remain proprietary designs. The most common are the Tyton joint, developed by U.S. Pipe, the Fastite, by the American Cast Iron Pipe Co., and the Rapid, by Saint-Gobain PAM, which is marketed outside the U.S. Restrained joint systems are available too. Each of the four U.S. manufacturers has their own proprietary restrained joint system that generally involves a "boltless system". Clow Water Systems has the Super-Lock joint, Pacific States Cast Iron Pipe Co. has the Thrust-Lock system, Griffin Pipe Products has the Snap-Lock joint, U.S. Pipe has the TR-Flex joint, and American Cast Iron Pipe has the Flex-Ring joint. Also available are locking gasket systems. Available for the standard 'push-joint' systems are the Sure Stop gasket by McWane, Field Lok by U.S. Pipe, and Fast Grip by American Cast Iron Pipe Co. These locking gasket systems work on the "Chinese Box" principle where you can push the pipe together, but will be unable to pull it apart (without using a special tool or blow torch on the gasket). 

 
Manufacture

Ductile iron pipe is produced by a technique known as centrifugal casting, originally developed by Dimitr Sensaud deLavaud for cast iron pipe in 1918. The molten ductile iron is poured into a rapidly spinning water-cooled mold. Centrifugal force results in an even spread of iron around the circumference. 

 
Internal Coatings
Ductile iron pipe is somewhat resistant to internal corrosion in potable water and less aggressive forms of sewage. However, even where pipe material loss and consequently pipe wall reduction is slow, the deposition of corrosion products on the internal pipe wall can dramatically reduce the effective internal diameter and effectively choke flow, increasing pumping costs and lowering system pressure, long before the pipe itself is at risk of failure. A variety of linings are available to reduce or eliminate corrosion, including cement mortar, polyurethane and polyethylene. Of these, cement mortar lining is by far the most common. 

 
Cement Mortar Linings
The predominant form of lining for water applications is cement mortar centrifugallly applied during manufacturing. The cement mortar comprises a mixture of cement and sand to a ratio of between 1:2 and 1:3.5. For potable water, portland cement is used, for sewage it is common to use sulfate resisting or high alumina cement.
Cement mortar linings have been found to dramatically reduce internal corrosion. A DIPRA survey has demonstrated that the Hazen-Williams factor of cement lining remains between 130 and 151 with only slight reduction with age. 

 
External Coatings
Unprotected ductile iron, similarly to cast iron, is intrinsically resistant to corrosion in most, although not all, soils. Nonetheless, due to frequent lack of information on soil aggressiveness, and to extend the installed life of buried pipe, ductile iron pipe is commonly protected by one or more external coatings. In the U.S. and Australia, loose polyethylene sleeving is preferred. In Europe, standards recommend a more sophisticated system of directly bonded zinc coatings overlaid by a finishing layer be used in conjunction with polyethylene sleeving. 

 
Polyethylene Sleevings
Polyethylene sleeving was first developed by CIPRA (since 1979, DIPRA) in the U.S. in 1951 for use in highly corrosive soil in Birmingham, Alabama. It was employed more widely in the U.S. in the late 1950s and first employed in the U.K. in 1965 and Australia in the mid 1960's. 

 
Polyethylene sleeving comprises a loose sleeve of polyethylene sheet that completely wraps the pipe, including the bells of any joints. Sleeving inhibits corrosion by a number of mechanisms. It physically separates the pipe from soil particles, preventing direct galvanic corrosion. By providing an impermeable barrier to ground water, the sleeve also inhibits the diffusion of oxygen to the ductile iron surface and limits the availability of electrolytes that would accelerate corrosion. It provides a homogeneous environment along the pipe surface so that corrosion occurs evenly over the pipe. Finally, the sleeve restricts the availability of nutrients which could support sulfate-reducing bacteria, inhibiting microbially-induced corrosion. Sleeving is not designed to be completely water-tight but rather to greatly restrict the movement of water to and from the pipe surface. Water present beneath the sleeve and in contact with the pipe surface is rapidly deoxygenated and depleted of nutrients and forms a stable environment in which limited further corrosion occurs. An improperly installed sleeve that continues to allow the free flow of ground water is not effective in inhibiting corrosion. 

 
Polyethylene sleeves are available in a number of materials. The most common contemporary compositions are linear low-density polyethylene film which requires an 8 mil or 200 m thickness and high-density cross-laminated polyethylene film which requires only a 4 mil or 100 m thickness. The latter may or may not be reinforced with a scrim layer. 

 
Polyethylene sleeving does have limitations. In European practice, its use in the absence of additional zinc and epoxy protective coatings is discouraged where natural soil resistivity is below 750 ohm/cm, where resistivity is below 1500 ohm/cm and the soil is frequently water logged, where there are additional artificial soil contaminants or where there are stray currents. Due to the vulnerability of polyethylene to UV degradation, sleeving, or sleeved pipe should also not be stored in sunlight, although carbon pigments included in the sleeving can provide some limited protection. 

 
Polyethylene sleeving is standardised according to ISO 8180 internationally, AWWA C105 in the U.S., BS 6076 in the U.K. and AS 3680 and AS 3681 in Australia.
 

Zinc Coatings
In Europe, ductile iron pipe is typically manufactured with a zinc coating overlaid by an either bituminous or polymer, normally epoxy, finishing layer. EN 545/598 mandates a minimum zinc content of 135 g/m2 (with local minima of 110 g/m2 at 99.99% purity), and a minimum average finishing layer thickness of 70 m (with local minima of 50 m) although some manufacturers, notably Saint-Gobain PAM considerably exceed these thicknesses. 

 
No current AWWA standards are available for bonded coatings (zinc, coal tar epoxy, tape-wrap systems as seen on steel pipe) for ductile iron pipe, DIPRA does not endorse bonded coatings and AWWA M41 generally views them unfavourably, recommending they be used only in conjunction with cathodic protection .
 

Bituminous Coatings
As noted, zinc coatings are generally not employed in the U.S. and Australia. In order to protect ductile iron pipe prior to installation, pipe is instead supplied with a temporary 1 mil or 25 m thick bituminous coating. This coating is not intended to provide protection once the pipe is installed. 

 
Producers 

 
U.S. 

 
In the United States ductile iron pipe is manufactured by McWane Inc.(consisting of four foundries - McWane Cast Iron Pipe Co., Clow Water Systems Company,Atlantic States Cast Iron Pipe Co. & Pacific States Cast Iron Pipe Co.), Griffin Pipe Products, U.S. Pipe & Foundry, and American Cast Iron Pipe Co. The primary headquarters for three of these four companies are based in Birmingham, AL. 

 
Europe 

 
Saint-Gobain PAM, a subsidiary of Saint-Gobain and the world's largest ductile iron pipe manufacturer, is predominant in Europe. Saint-Gobain PAM formed in 1970 following the merger of Saint-Gobain and the company Pont--Mousson (PAM). Saint-Gobain PAM's ductile iron pipe factory in the town of Pont--Mousson remains the world's largest. 

 
Australia 

 
In Australia, Tyco Flow Control Pacific, a subsidiary of Tyco International, is by a wide margin the largest Australian manufacturer of DICL, after having purchased Tubemakers Water and its single Yennora Manufacturing Facility in Sydney's west, from BHP in 1999. 

 
Industry Associations 

 
In the United States ductile iron pipe is often promoted to municipalities and consulting engineers by DIPRA, which is the Ductile Iron Pipe Research Association. Their focus is to promote the benefits of using ductile iron pipe on utility projects (water & sewer) over alternate products like PVC, PCCP, and HDPE. 

 
Environmental 

 
Ductile iron pipe in the developed world is normally manufactured exclusively from scrap steel. Ductile iron pipe itself can be recycled. In the U.S. with the growing 'Green' movement ductile iron pipe is in a natural position to regain market share lost to its largest competitor, the PVC industry, over the past 40 years. PVC pipe has negative environmental issues ranging from carcinogens produced at resin plants to the burning of it releasing dioxins into the atmosphere to its carbon footprint. 

 
Colloquialisms
As a commonly used construction material ductile iron pipe has assumed various colloquial shortened names. In America it is commonly referred to as 'ductile', in the UK, by the initials, 'DI', and in Australia as the acronym, DICL (Ductile Iron - Cement Lined), pronounced 'dickle'.