: : Electrosteel Castings Limited - Ductile Iron Fittings - Accessories

Electrosteel

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Restrained Joints

Rubber Gaskets

	DUCTILE IRON FITTINGS - ACCESSORIES - RESTRAINED JOINTS

This is a joint where restraining mechanism is incorporated to normal flexible Push-On-Joints. In fittings like Bends, Tees and Reducers, thrust forces are generated by internal pressure at cross-sectional and directional changes. Normal flexible Push-On-Joints are incapable of withstanding such axial forces. As a result, there are chances of pull out of the pipe from the joints leading to leakages.

To counter these forces conventional thrust blocks becomes uneconomical and difficult fo provide as the fittings are short bodied. The current approach is to provide restraining devises on pipes placed on the both the sides of the fittings under thrust. Thus the length of fittings is effective in erased and the frictional force between the effective long fitting and soil frictional force take care of the thrust force.

Such joints ideally suit the following site of laying conditions:

Directional changes in pumping.
Unstable ground conditions like marshy grounds, subsidence areas,seismic zones etc.
Hilly terrains.

Electrosteel offers such joints in size ranging DN 80 to DN 1100. The mechanism adopted by Electrosteel for restrained joint involves a welding bead at the spigot end, glands, locking ring and bolts & nuts. The gland and locking ring, connected with socket collar by bolts & nuts, create the restraining force against the weld bead of the spigot, all the accessories are supplied generally in Dl.

Restrained joints of Electrosteel offers nearly the same degree of deflection as that of flexible Push-On-Joints. The performance of this joint will however depend on following the correct procedures of design based on line pressure and velocity of the fluid. Electrosteel provides all the details of such procedures to its customers.

Details of Accessories

Nominal Size (DN)	GLANDS		BOLTS
(mm)	No. of Holes	Hole Dia. (mm)	No. per joint	Size (mm)	Length (mm)
80	4	28	4	M24	70
100	4	28	4	M24	70
150	6	28	6	M24	70
200	8	28	8	M24	70
250	6	30	6	M27	102
300	8	30	8	M27	102
350	8	30	8	M27	102
400	10	30	16	M27	102
450	16	30	16	M27	102
500	16	30	16	M27	102
600	2 0	3 0	2 0	M27	102
700	24	30	24	M27	123
800	30	30	30	M27	123
900	30	30	30	M27	123
1000	30	30	30	M27	123