Prestressed Concrete Cylinder Pipe (PCCP) Types

Prestressed concrete cylinder pipe consists of a structural, high-strength concrete core, a steel cylinder with steel joint rings welded at each end providing water tightness, steel prestressing wire, and a portland cement-rich mortar coating. Two types of PCCP are manufactured: lined cylinder pipe (LCP), which is detailed in Fig. A and embedded cylinder pipe (ECP), which is detailed in Fig. B.

Fig. A: Lined cylinder pipe (LCP) Profile

Fig. B: Embedded Cylinder Pipe (ECP) Profile

Lined cylinder pipe has the entire concrete core placed inside the steel cylinder. The cured concrete core and steel cylinder are then helically wrapped with prestressing wire, which is subsequently coated with cement mortar. Embedded cylinder pipe has the concrete core placed both outside and inside the steel cylinder by a
vertical casting operation. The cured concrete core and steel cylinder are then helically wrapped with prestressing wire and, as LCP, is coated with cement mortar.

Available Size Ranges

LCP is normally manufactured with inside diameters ranging from NPS 16 (DN 400) through NPS 48 (DN 1200), although larger sizes have been made. ECP is normally manufactured with inside diameters ranging from NPS 54 (DN 1350) through NPS 144 (DN 3600), but diameters smaller and larger than this range are
possible. 

The nominal laying length for pipe up to and including NPS 114 (DN 2850) is usually 20 ft (6 m), and 16 ft (4.9 m) for larger sizes. These diameter ranges and laying lengths can sometimes vary by manufacturer, so the user should check with suppliers on specific sizes. In larger sizes, the laying length can be controlled by the weight of the piece and the manufacturer’s and installing contractor’s ability to handle it.

Fittings and Special Pipe

A wide range of fittings and special pipe lengths are available for all types of project requirements. Fittings are manufactured from steel plate which is cut, rolled, and welded to form the required shape. The completed steel shell is lined and coated with portland cement mortar for corrosion protection. Each fitting is designed for the same external load and internal pressure as the adjoining pipe. Common fittings are elbows, tees, wyes, reducers, wall pieces, and adapters. Adapters are needed for connections to other types of joints such as flanges, mechanical joints, and couplings. 

Figures C through F show the general configurations of elbows, tees, concentric reducers, and flange adapters.

Fig. C: Typical elbow fitting

Fig. D: Typical tee fitting

Fig E: Typical concentric reducer fitting

Fig. F: Typical flange adapters

Special pipe consists of prestressed pipe lengths with additional features such as outlets or beveled ends. Prestressed pieces with a laying length shorter than the standard constitute a special pipe that can be supplied to match specific job requirements.