PressureCast Steel PipeThe Steel Pipe “Heavyweight”

How It’s Made

NOV® Ameron® PressureCast Steel Pipe is a patent-pending steel pipe manufactured with a “twist”. The “twist” is that once the steel cylinder is fabricated with rubber gasket joints, a concrete lining is placed in the cylinder and pressurized before the concrete is cured. The pressure pushes the concrete against the cylinder, stretching the cylinder to a stress below the steel’s yield point. After the concrete is cured, the pressure is released. The steel cylinder then compresses the concrete lining. The exterior of the steel cylinder can be coated with mortar, tape, or paint, as appropriate for the pipe service application. The steel cylinder remains in tension even after all creep and shrinkage of the concrete has occurred.

How It’s Designed

All design formulas for PressureCast Steel Pipe have already been fully vetted through the AWWA Standard peer review process. The maximum design working stress for the PressureCast Steel Pipe cylinder is limited to 50% of the steel yield stress, and the maximum stress at surge pressure is limited to 75% of the yield stress, just as is applicable to ordinary C200 steel pipe. Primary formulas for the concrete lining and steel cylinder stress calculations for the pressure cast process are from AWWA C304. From these calculations, PO, the pressure at which all compression in the concrete lining has been relieved, is determined. The steel stress at the maximum design working pressure for PressureCast Steel Pipe is allowed to be the steel stress at PO plus an additional 18,000 psi. This is conservatively comparable to ordinary mortar-lined steel pipe, for which the steel stress at maximum design working pressure is 21,000 psi.

External load calculations for PressureCast Steel Pipe are based upon standard AWWA steel pipe laminar analysis, i.e., the stiffness of the concrete lining, steel cylinder, and any mortar coating are calculated as separate laminar rings and then added together. External load capacity for various embedment conditions is then calculated in accordance with AWWA Manual M11 Steel Water Pipe: A Guide for Design and Installation.

The proven performance limit for the concrete lining in PressureCast Steel Pipe is to assure no cracks wider than 1/16” when the pipe is under a combination of working pressure and a maximum design pipe defl ection of 2%. The 1/16” crack width limit is common for mortar linings on ordinary AWWA C200 steel pipe and recognized as a crack width that will readily close autogenously when the pipe is fi lled with water.

Combined load testing of 60-inch PressureCast Steel Pipe establishes pipe performance envelope.

How It’s Made

• No imported embedment materials

• Ship without struts or end caps

• Install without struts

• Rubber gasket joints in all diameters

• No maximum D/t ratio for handling

• No minimum cylinder thickness for vacuum condition

• Higher working stress allows less steel

• Proven 50+ year durability of concrete lining

PressureCast Steel Pipe The Steel Pipe “Heavyweight”

Test Results

120-degree sand-bearing and full-embedment combined load tests have demonstrated a safety factor greater than 2 for a PressureCast Steel Pipe design defl ection limit of 2%, and that the 18,000 psi additional steel stress above the steel stress at Po is conservative. Testing and fi eld experience have established that PressureCast Steel Pipe can be shipped, handled, installed,

Available Diameters

PressureCast Steel Pipe is initially being offered for vertically-cast pipe in diameters 48” and larger. Equipment fabrication lead times are applicable.

and backfi lled without struts or end caps. Testing has shown PressureCast Steel Pipe is much stiffer than necessary to allow bedding and backfi lling with, and consolidation of, screened excavated material, including clays.

Available Diameters

© 2012 National Oilwell VarcoD392004569-MKT-001 Rev. 02

National Oilwell Varco has produced this brochure for general information only, and it is not intended for design purposes. Although every effort has been made to maintain the accuracy and reliability of its contents, National Oilwell Varco in no way assumes responsibility for liability for any loss, damage or injury resulting from the use of information and data herein. All applications for the material described are at the user’s risk and are the user’s responsibility.All brands listed are trademarks of National Oilwell Varco.

w w w. n o v. c o m / A m e r o nw w w. n o v. c o m / A m e r o n

O n e C o m p a n y . . . U n l i m i t e d S o l u t i o n s

NOV Corporate Headquarters7909 Parkwood Circle DriveHouston, Texas 77036United StatesPhone: 713 375 3700Fax: 713 346 7687

NOV Ameron

HeadquartersWater Transmission Group10681 Foothill Boulevard, Suite 450Rancho Cucamonga, California 91730United StatesPhone: 909 944 4100Fax: 909 944 4113

10100 W. Linne RoadTracy, California 95377United StatesPhone: 209 836 5050

2325 S. 7th StreetPhoenix, Arizona 85034United StatesPhone: 602 252 7111

12455 Arrow RouteEtiwanda, California 91739United StatesPhone: 909 899 1716

Protective Linings Division201 North Berry StreetBrea, California 92821United StatesPhone: 714 256 7755

Tubos Y Activos S de RL de CVLote 6 FR Fw Col. Sanchez, ToboadaMexicali, B.C. CP 21360Phone: 686 553 1124

American Pipe and Construction International APCIApartado Aereo No. 90087Santa Fe de Bogota, ColombiaPhone: 57 1 6740600

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