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Products > Pre-stressed Concrete Cylinder Pipe (PCCP)

 

[Dimensions] [Deflections] [Manufacturing]

 

Pre-stressed Concrete Cylinder Pipe (PCCP) is a rigid pipe designed to take optimum advantage of the tensile strength of steel and of the compressive strength and corrosion inhibiting properties of concrete.  PCCP is designed and manufactured in accordance with American Water Works Association Standard C301.

PCCP is produced in Saudi Arabia in diameters of 900 to 4000 mm in laying lengths of 7.5 meters.  Smaller and considerably larger sizes can be produced.  It has been used for over 40 years for such applications as water transmission and distribution pipelines, cooling water systems, sewer force mains, inverted siphons, sub aqueous pipelines, and liners for pressure tunnels.

Combined–Load Design

PCCP is designed by a proven analytical method which considers all elastic and inelastic deformations in the pipe and conservatively limits tensile and compressive stresses for any combination of internal pressure and external load.  A typical design curve is shown, the most economical design being one which falls on the curve.  The overload curve, also shown, provides for live loads, water hammer or other transient loads.

The operating pressure range for pipe 900 to 4000 mm in diameter is shown for one and two layers of pre-stressing wire.  Pipe can be designed and manufactured for operating pressures higher than shown with three or more layers of pre-stressing wire.

Customized System Design

Ameron provides the customer’s engineer with a complete engineering package for each PCCP project. This includes pipe design calculations and fabrication details for each item furnished.  For complicated lines and industrial installations, a pipeline layout is provided showing each component’s location.  Each component is numbered to identify its position in the line.

Fittings, fabricated at the PCCP pipe manufacturing facility, are designed to avoid the need for cutting and fitting in the field.  Almost any size or configuration of fitting can be furnished to satisfy the requirements of the system.

Field Assembly

PCCP is rapidly and economically installed by means of self-centering steel joint rings sealed with confined rubber rings.  The reliability and water-tightness of this type of joint has been proven by 50 years of field experience.  The double rubber rings permit pressure testing of each joint as the pipe is installed, thus assuring its water-tightness.  Installation rates of 30 to 50 pipe sections per day per installation crew are frequently obtained.

Changes in Direction

Long-radius curves and minor changes in pipeline alignment and grade are accommodated by deflecting the pipe joints or by using pipe sections with ends beveled up to 5 degrees.  For short-radius turns, fabricated elbows are provided.

Restraint of Thrust

Hydraulic thrust in the pipeline can be resisted by field welding the joint rings of assembled sections for a sufficient distance each side of the thrust point to develop the required longitudinal restraint.  This method eliminates the need for expensive and sometimes unreliable concrete thrust blocks.

Corrosion Resistance

Corrosion of steel elements in PCCP is inhibited by a passivating iron oxide film which quickly forms and is maintained in the highly alkaline concrete or cement-mortar encasement (pH at least 12.5).  As a supplemental protection, all pipe and fittings are coated with coal-tar epoxy.

Carrying Capacity

The smooth interior surface of PCCP provides hydraulic carrying capacity with a Hazen-Williams flow coefficient in the range of C=140 to 150.  Because concrete does not corrode, the carrying capacity is not decreased by age.

Structural Integrity

The rigid construction of PCCP makes it highly resistant to physical damage and eliminates the possibility of vacuum collapse.  Because of this high load-carrying capacity, PCCP is not dependent on lateral soil support, and therefore bedding and backfilling procedures are much less stringent than for flexible pipe.

 

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