Cement Mortar Lining for Pipe Fittings

Cement mortar lined pipe fittings are a type of pipe fittings that have an internal lining of cement mortar to provide protection against corrosion and erosion. The cement mortar lining is a thin layer of cement-based material that is applied to the inner surface of the pipe fittings to create a smooth and durable barrier that protects against the corrosive effects of water and other fluids.

Cement mortar lined pipe fittings are commonly used in water and wastewater applications where the pipes are exposed to corrosive fluids. They are particularly effective in reducing the risk of corrosion in steel pipes and fittings, which are commonly used in water distribution systems.

The cement mortar lining provides a protective barrier that is resistant to the corrosive effects of chlorine, hydrogen sulfide, and other chemicals commonly found in water and wastewater. It also helps to reduce the buildup of sediment and biofilm that can lead to reduced flow and increased maintenance costs.

Features of cement mortar lining:

1) Self-healing with the proceeding hydration reaction of cement:

The cement mortar lining will shrink gradually. Therefore, it is inevitable to form radial displacement and small cracks. This is a unique feature of cement mortar, which is allowable by the standard. Thus, no unfavorable influence on the mechanical stability of the lining will be brought by such cracks and radial displacement, as well as other cracks caused during manufacturing or transportation. When the pipe with cement mortar lining contact water, these cracks and radial displacement will be closed and healed along with expansion of the linings and continuous hydration of cement; therefore, the anticorrosion effect won’t be influenced.

2) Good mechanical property:

* Expansion coefficient:

The linear thermal expansion coefficient of cement mortar lining is 12 x 10-6/℃ , which is almost equal to that of ductile iron (11 x 10-6/℃ ). Therefore, it can reduce the risk of crack generation due to difference of thermal expansion coefficients. 

* Good adherence and anti-vacuum performance.

* Good resistance to longitudinal bending and to ovality.

* Good resistance to vibration and impact.

* With excellent abrasion resistance, cement mortar lining can be used to convey raw water with highly abrasive particles.

* Excellent hydraulic performance.

Application fields:

Ductile iron pipe fittings with common silicate cement mortar lining is applicable for water-supply project;

Ductile iron pipe with sulphur resistant cement mortar lining is applicable for water supply project and water transmission project with water quality.

Ductile iron pipes with high-alumina cement mortar lining are applicable for the conduction of sewages and industrial wastewater containing certain chemical substances.