Assembly of the joint is quick and simple, and may, according to size and local conditions, be carried out by any of the following methods.

Crowbar method
Complete entry of the spigot into the socket may be obtained by pushing with a crowbar or a suitable lever against the face of the entering Ductile Iron Pipe.

Fork tool method
Maybe used for 100mm and 150mm Ductile Iron Pipe. The fork is placed over and behind the socket of the last Ductile Iron Pipe laid. A wire rope with eye at one end and a hood at the other is connected to the socket of the Ductile Iron Pipe to be jointed as shown in the diagram. The fork is now pulled in direction of arrow and the spigot enters the socket. Reasonable force should only be used.

Trifor or Come along method
For joint above 150mm a wire rope or chain can be used as shown in the diagram.

Trench excavator method
When the trench is being prepared by using a back hoe or excavator, wither machine may also be used to push the spigot home. This system is mainly used on large diameter Ductile Iron Pipe and a timber header should be placed between the Ductile Iron Pipe and the bucket to prevent damage to the Ductile Iron Pipe.

Before assembling the joint, the spigot of the ductile iron pipe and interior of socket of the adjacent ductile iron pipe should both be thoroughly cleaned.

Insertion of gasket

The gasket should be wiped clean, flexed as shown in the diagram, and then placed in the socket with bulb leading. The groove in the gasket must be located on the retaining bead in the socket, and the retaining heel of the gasket firmly bedded in its seat so that the heel of the gasket is not proud of the mouth of the ductile iron pipe. Ensure the gasket fits evenly around the whole circumference of the ductile iron pipe, removing any bulges from the ductile iron pipe that prevents the proper entry of the spigot end.

Lubrication

A thin film of lubricant is applied to the inside surface of the gasket which will be in contact with the entering spigot. In addition, a thin film of lubricant should be applied to the outside surface of the spigot end.

Initial entry of spigot

The spigot of the ductile iron pipe being jointed must be aligned and entered carefully into the adjacent socket until it makes contact with the gasket. Final assembly of the joint is completed from this position.

Completely assembled joint

Joint assembly is completed by forcing the spigot end of the entering ductile iron pipe past the gasket, which is thus compressed, until the first painted strip on the end of the ductile iron pipe disappear and the second painted strip is approximately flushed with the socket face. If joint is difficult to assemble, the spigot should be removed and rotated 90 degree before attempting to assemble a second time. If the joint is still difficult to assemble, the spigot should be removed and the gasket examined.

Deflection

The joints can be deflected in any directions up to 5 degree for ductile iron pipe up to 300mm diameter nominal size, up to 4 degree for 350mm and 400mm size and up to 3 degree for 450mm to 700mm. All spigots must be chamfered. When making a joint, ductile iron pipe should be always be in line and if required, deflection made after jointing.

Before the production of Ductile Iron Pipe, Cast Iron Pipe is known as the most suitable pipe for the industries. After the production of Ductile Iron Pipe, it’s well known and retains all the attractive qualities from Cast Iron such as machinability, corrosion-resistance, additional strength, toughness, and ductility. The chemical properties for Ductile Iron Pipe and Cast Iron Pipe are different too.

Ductile Iron Pipe is largely used in the industry since 1955. Most probably Ductile Iron Pipe is used for modern water, wastewater systems and etc. There are more than for decades of field experience have proven Ductile Iron Pipe’s strength, durability, and reliability for transporting raw, potable water, sewage, slurries, and process chemicals. Ductile Iron pipe is good in it’s function of corrosion-resistance, it has been proven that its’ corrosion-resistance is equal or greater than the Cast Iron Pipe. With that said, Ductile Iron Pipe can be stand for more longer than Cast Iron Pipe without reparing, in a long term basis, the cost used for ductile iron pipe will be lesser than cast iron pipe.

Ductile Iron Pipe is usually manufactured by the piping supplier in 6 metre nominal laying lengths and range of 80mm – 2600mm diameters of standard pressure classes and nominal wall thicknesses. There is several methods for Ductile Iron Pipe jointing, assembling, cutting, installing, and ovality correction too. Of course, the cost for ductile iron pipe will be higher if comparing with cast iron pipe and other pipes, but it’s more economical in long run basis.

Click here to view the video on how ductile iron pipe is made.

Source : Dipra & Brouchure from ACI Holdings