How to Joint 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.

	A (mm)			A (mm)
Nominal size	min	max	Nominal size	min	max
80	10	14	600	14	18
100	10	14	700	16	20
150	10	14	800	16	20
200	10	14	900	18	22
250	10	14	1000	20	24
300	10	14	1100	22	26
350	10	14	1200	24	28
400	12	16	1400	28	32
450	12	16	1600	32	36
500	14	18

Tagged as: Ductile Iron Pipe, Installation Pipe