The socket and spigot push-on joint is an extremely reliable joint, used extensively throughout the world on various pipe designs. Destructive tests have shown that the joint never leaks. The joint furthermore has a very good resistance to negative pressure conditions as well as root infiltration.
Apart from certain advantages regarding laying or accommodating ground movement, the joint deflection allows long radial curves to be negotiated without using fittings, as well as some adjustments to the pipeline route.
After finish assembling joint, in respect of diameter adjust angular deflection which should satisfy the requirements mentioned in the below list.
In some pipe laying conditions such as unstable ground or extremely hilly terrain, axial pull-out forces are generated by internal pressure at cross-sectional and directional changes. Normal flexible joints are incapable of withstanding such axial forces, unless used in conjunction with conventional thrust blocks.
An elegant solution, that provides the benefit of the standard spigot and socket jointing arrangement, is in the form of a joint where the restraining mechanism is incorporated in the normal flexible spigot and socket. This offers the same degree of deflection as standard jointing.
Mechanical joints are particularly useful due to their size and weight in applications where the construction of anchor blocks is difficult, for example in congested areas or low strength soils.