ISO 4179 pdf download – Ductile iron pipes and fittings for pressure and non-pressure pipelines —Cement mortar lining

ISO 4179 pdf download – Ductile iron pipes and fittings for pressure and non-pressure pipelines —Cement mortar lining.
Apart from the inner surface of the socket, the parts of the pe or fitting coming in contact with the transported water shall be entirely covered with mortar.
The consistency ot the mortar, me lime and the speed of centrifugatlon, and the speeds of rotation and translation of the proiection head shall be controlled so as to achieve a dense and continuous lining. The mortar shall be free of any cavities or visible air bubbles, so that minimum thickness and optimum density are ensured at all points.
4.3 CurIng
The fresh lining shall be cured at temperatures greater than 0 °c. Any loss of water from the mortar by evaporation shall be sufficiently slow that hardening is not inweded This may be achieved, for example, by means of controlled atmosphere. closed pipe ends or by application of a seal coat to the still moist thing.
The curing conditions shall be such as to achieve sufficient hardening of the lining and compliance with me requirements of Clause 6
4.4 Seal coat
Unless otherwise specified, the manufacturer has the option of providing or not providing a seal coat. The seal coat shall not affect adversely the quality of the transported water, For water intended for human consumption. national hygienic requirements in force in the country where the pipes and fittings are to be installed shall be fulfilled.
When a seal coat is supplied, it shall be in accordance with ISO 16132.
4.5 Repairs
Repairs to damaged or detective areas are allowed. They should be carried out according to the manufacturer’s Instructions. The damaged mortar shall first be removed from these areas. Then the detective part shall be repaired by using, for example, a trowel with fresh mortar so that a continuous lining having a constant thickness is again obtained.
For the repair operation, the mortar shall have a suitable consistency; if necessary, additives may be included to obtain good adhesion against the side of me existing undamaged mortar.
Sufficient curing shall be provided to the repaired areas.
5 Thickness of lining
5.1 Thickness requIrements
The nominal thickness of the lining and the minimum thickness at one point are given wi Table 1. The lining thickness measured at any one point in the pipe shall not be smaller than the minimum value given in Table 1.
For partially tilled sewage pipelines, by agreement between manufacturer and purchaser. the lining thickness may be Increased, and or high alumina cement mortar, polymermodifled mortar or suitably coated mortar may be used.
6 Surface condition of hardened lining
The cement mortar lining shall exhbt a generally smooth finish on its entire surface. However, the structure of the Ining and its surface finish are related to the lining process: surface textures inherenl In the method of manufacture (e.g. orange peel effects) shall be acceptable provided that they do not re&ce the thickness of the lining to less than the minimum value at one point as specified in Table 1. Only firmly embedded sand grains are allowed to appear on the surface of the lining.
For centrifugally applied linings, a thin laitance and cement rich layer. conrising tine sand and cement, may be formed on the inner surface of the lining. It may extend up to approximately one quarter of the total thickness of the mortar.
Due to the complex internal shape of the fittings and to the application process (rotating protection head), the lining of fillings may show a corrugated surface provided that it does not reduce the thickness of the lining to less than the minimum value at one point as specified in Table 1.
NOTE It s known that the surface condihon has ery Isle effect on the hydraulic characteristics, the main factors being the effective internal diameter of the pes and the shape of the fittings.
On contraction ot the lining, the formation of cracks and radial displacements cannot be avoided (see Figure 1).
These cracks and radial displacements, together with other isolated cracks whth may result from manufacture
or may develop &ring transportation, are acceptable It their width does not exceed the values In Table 1.
Cracks shall not be detrimental to the mechanical stability of the bnang.
NOTE 2 It is known that these cradcs and radial displacements will close and heal when the h.ag comes into contact with water due to re-swelting of the lining and continued hyckallon of the cement.