Piping Systems Throughout history, the need for freshwater has played a critical role in the development of human civilization. The Romans built massive gravity-fed aqueducts to direct water for farmland, mining, drinking, and even bathing pools and fountains. Innovations like the water wheel and mechanical pump further pushed water to new heights and applications. Eventually, the perfection of pipe has let us branch out across the world bringing our water supply along in tow. Legacy Piping Systems The origins of pipe date back to the Roman empire. Lead pipe was originally conceived for its ability to be easily formed and cost-effective maintenance. Despite our modern understanding of the health hazards associated with lead poising many of the adverse consequences of lead pipe were never fully understood. Lead water pipes have been installed in homes as late as the early 20 th century and some lines remain in service today. Wooden water mains have been known to be used as early as the 13 th century to transmit water to villages. These systems were often made from Elm and originally relied on elevated streams to feed water with gravity. Boston was the first city in the United States to install wooden water mains in 1652 and was considered a pioneer in water infrastructure. There are many problems with timber piping including rotting, warping, and insects however some wooden water mains are still found in use today. Steel pipe was then introduced to replace wood and lead in the early 17 th century as our steel manufacturing processes improved. Steel pipe is very corrosive, so it was found not to be a good choice of material for long term service. In the early 19 th century, cast iron pipe was introduced in many cities. Made from grey iron, was found to be very long lasting and durable. The initial design called for a flange type (flat face) end, mated with another flange using an elastomer gasket to seal the pipe sections. Cast iron pipe was first made by horizontally casting, then vertical and eventually centrifugally casting method which is the most common manufacture used today. Ductile Iron Pipe Ductile Iron pipe was introduced in the 1970’s as an alternative to cast iron. With the application of magnesium and improved casting techniques, it was found to have better strength and ductility. Today, it is used as the primary piping material used to transport raw and potable water, sewage, slurries, and process chemicals. Lighter, stronger, and more durable than cast iron, ductile iron pipe uses a bell and spigot type mating system. Using a gasket to join the bell end to the spigot end, pipe sections can quickly and easily be mated for installation. Other configurations like mechanical joints use a following gland to bolt the spigot end of the pipe to the mechanical side. Ductile iron pipe is centrifugally cast with the integral bell manufactured conforming to standard ANSI C150.A21.0 Ductile iron pipe is made with a cement mortar lining interior to resist the corrosion process and can be made with different thicknesses (or grades), depending on what is specified by the engineer. Pipe classes on small diameters range from class 350 to class 56, higher classes having a thicker interior lining. Larger diameter pipe ranges from class 150 to class 56. The outside of the pipe is generally applied with an asphalt coat to deter corrosion from the soil. Other available outside coatings include zinc, asphalt, or even water-based paints. If extra protection is required, Ploy sleeving (poly wrap) can be used to encase the pipe to protect from adverse soil conditions. Ductile iron pipe is usually manufactured in 18’ or 20’ lengths and is available in 3”- 64” outside diameters. The spigot end of the pipe can be used with a mechanical joint or slip-on type fittings if the pipeline must curve or branch off for other transmission lines. Pipe can be manufactured as unrestrained or restrained using special gaskets and end configurations. Flange piping is also available (usually CL53 and above) cut to specific lengths for field cuts or inside work. Ductile iron pipe is rated to have a 100 year plus life with the benefit of low maintenance. This makes ductile iron pipe more superior to other products on the market today. The manufacturing process for casting ductile pipe supports a controlled outside diameter. This allows for the pipe to mate with standardized fittings, couplings, and other ancillary piping products. Ductile Iron Pipe Manufacturing Standard Ductile Iron Pipe is a centrifugally cast product. A controlled amount of molten iron is introduced into the rotating mold, which generates a centrifugal force that holds the iron in place against the mold until it solidifies. The pipe is then removed and furnace-annealed to obtain the prescribed physical properties. The following acceptance test requirements set forth by ANSI/AWWA C151/A21.51 must be met before the pipe is declared ready for shipment 1. Tensile test: Ultimate strength: 60,000 psi minimum Yield strength: 42,000 psi minimum Elongation: 10% minimum 2. Impact test: 7 ft.-lb. minimum at 70°F 3 ft.-lb. minimum at -40°F 3. Hydrostatic test: Every piece of Ductile Iron pipe is subjected to a hydrostatic test of at least 500 psi before it leaves the foundry. In addition to these acceptance tests, Ductile Iron manufacturers conduct additional quality control. Tests throughout the manufacturing process ensure the highest-quality castings Ductile Iron Pipe Standards • ANSI/AWWA C104/A21.4 American National Standard for Cement-Mortar Lining for Ductile Iron Pipe and Fittings for Water • ANSI/AWWA C151/A21.51 American National Standard for Ductile Pipe Centrifugally Cast, for Water • ANSI/AWWA C115/A21.15 American National Standard for Flanged Ductile Iron Pipe with Ductile or Grey Iron Threaded Flanges • ANSI/AWWA C105/A21.5 American National Standard for Polyethylene Encasement for Ductile Iron Pipe Systems • ANSI/AWWA C153/A21.53 American National Standard for Ductile Iron Compact Fittings for Water Service • ANSI/AWWA C150/A21.50 American National Standard for the Thickness Design of Ductile Iron Pipe • ANSI/AWWA C110/A21.10 American National Standard for Ductile Iron and Grey Iron Fittings, 3-Inch through 48-Inch for Water • ANSI/AWWA C600 AWWA Standard for Installation of Ductile Iron Water Mains and Their Appurtenances • ASTM A716 Standard Specification for Ductile Iron Culvert Pipe • ANSI/AWWA C110/A21.11 American National Standard for Rubber Gasket Joints for Ductile Iron Pressure Pipe and Fittings • ASTM A674 Standard Practice for Polyethylene Encasement For Ductile Iron Pipe for Water or Other Liquids • ASTM A746 Standard Specification for Ductile Iron Gravity Sewer Pipe Ductile Iron Pipe Standards Ductile Iron Pipe Pressure & Thickness Class Ductile Iron Pipe Size, Dimension and Pressure Rating Ductile Iron Pipe Joints Push-On Joint Push on pipe joints are the easiest and most common method of connecting ductile iron pipe.  This joining method was developed in the 1950s to provide a faster and easier assembly. Connecting the pipes forces a bottle tight seal around the gasket allowing this system to be used in wet and even submerged applications. Mechanical Joint Mechanical Joints were originally developed for the oil and gas industry in the late 1920s but have found a preference in water works. Despite being commonly replaced by the push-on joint, the mechanical joint is a convention method for joining pipe. Restrained Joint The restrained joint is a special variation of either the push-on or mechanical joint. Used in addition with thrust blocks, the restrained joint provides support against thrust forces due to internal pressures. The design of the restraint fits further past the initial joining region to anchor the joint to a more secure part of the pipe. Flanged Joint Flanged Joints are use in applications where installations are not flexible a rigidity is important. This method is typically used for above ground systems including open bays and pipe galleries. The flange connection utilizes a gasket between the two mating flanges surrounded by a series of bolts to create a seal. Ball-and-Socket Joint The ball and socket joint provides a blotless solution to joining pipe while also offering the most flexibility and deflection ( up to 15° per joint ). These joints can be used with the addition of a restraint to help prevent joint separation and add more strength to the pipeline. The versatility of the ball and socket joint lends this joint to commonly be employed for submerged uses or in areas with erratic elevations and grades changes. Miscellaneous Joints There are a variety of different Joints that are modified styles of mechanical joint or stuffing box configurations. These miscellaneous joints were developed for use with tapping sleeves, repair sleeves, couplings, connectors, and other related products Ductile Iron Pipe Gasket Material Description Maximum Service Temperature (°F) Uses Water & Sewer Push-On & Mechanical Joint Gaskets Air Push-On Joint Gaskets Mechanical Joint Gaskets SBR (Styrene Butadiene) 150° 150° 125° Common: Drinking Water, Sea Water, Sanitary Sewage, Reclaimed Ware, Raw Water, Storm Water EPDM (Ethylene Propylene Diene Monomer) 212° 200° 150° Common: Alcohols, Dilute Acids, Dilute Alkalis, Ketones (MEK, Acetone), Vegetable Oil Other Drinking Water, Sea Water, Sanitary Sewage, Reclaimed Water, Raw Water Nitrile (NBR) (Acrylonitrile Butadiene) 150° 150° 125° Common: Hydrocarbons, Fats, Oils, Greases, Chemicals, Oils & Fluids, Refined Petroleum Others: Drinking Water, Sanitary Sewage, Reclaimed Water, Raw Water, Storm Water Neoprene (CR) (Polychloroprene) 200° 180° 150° Common: Greasy Waste Other: Sea Water Sanitary Sewage, Reclaimed Water, Raw Water, Storm Water Viton 212° 300° 300° Common: Aromatic Hydrocarbons, Fuels, Acids, Vegetable Oils, Petroleum Products, Chlorinated Hydrocarbons, Most Chemicals and Solvents. Other: Drinking Water, Reclaimed Water, Raw Water, Storm Ductile Iron Pipe Linings Ductile Iron Pipe installed in water systems today is normally furnished with a cement-mortar lining. Conforming to ANSI/AWWA C104/A21.4, the specifications for the cement-mortar lining strictly follow standards. Cement mortar lining prevents tuberculation by creating a high pH condition at the pipe wall as well as providing a barrier between the water and the pipe wall.  Additionally, cement linings create a smooth surface inside the pipe, meaning less friction and thus less head loss. The Hazen-Wi