Technical Papers

A collection of papers published by the Clay Pipe industry detailing many aspects of the design and installation of VCP sanitary sewers.  Also posted are other technical papers presented at conferences dealing with the wastewater treatment and collection systems.

Abstract - Using Historical Repair Data to Create Customized Predictive Failure Curves for Sewer Pipe Risk Modeling

Abstract - 2 page summary -- Seattle Public Utilities commissioned a study to develop customized failure curves based on recent experiential sewer pipe failure data. These new curves would be created...


Accumulation of slime in drainage pipes & their effect on flow resistance

The effects of slime layer development on hydraulic roughness of various types of pipe materials. Tests done with clean pipe & clean water. This test also looked at slime build up on several types o...


An Economic Approach to Sewer Pipe Selection - ASCE Paper

This is a lifecycle cost discussion based on least cost analysis program found in the Toolbox program.


An Economic Approach to Sewer Pipe Selection - NCPI Brochure

This is a life-cycle cost discussion based on the least cost analysis program found in the Toolbox program.


Behavior and Design of Buried Very Flexible Plastic Pipe

Spangler's equation and Watkins' formula, when used in the current form for very :flexible pipes, give poor results. Modifications are necessary to extend their use to very flexible plastic pipes. Sim...


Clay Pipe Installation - Advances in Load Factors

An evaluation of load factor values for classes B, C and D bedding systems and discussion of the development of a new system with higher load factors. Using strain gauges, the stresses on loaded pipe...


Consideration for Flotation When Controlled Low Strength Material (CLSM) is Used as a Bedding Material for VCP

CLSM is being successfully used as a bedding material for VCP. It simplifies the installation of pipe, reduces labor and inspection costs, allows for early backfill, is easy to place and provides a 2...


Consideration for the Use of Fly Ash when Controlled Low Strength Material (CLSM) is Used as a Bedding Material for VCP

Fly Ash has been used in CLSM mixes for wall stabilization, pavement support, utility conduit trench backfill and pipe bedding. CLSM as a bedding material for clay pipe provides the necessary support...


Designing Vitrified Clay Pipe Systems with EASE

This program discusses the development of the trench load program going back to Marston's development of the trench load equation and how it was adapted into a computer based design system for use by ...


Ductile Iron Corrosion Factors to Consider and Why

This paper discusses various corrosion considerations and controversies surrounding ductile iron pipe. Factors that should be considered during corrosion evaluations and pipeline designs are summariz...


Dude, Where's My Pipe? - Accelerated Corrosion Rate Threatens Phoenix Sewers

Discussion of Corrosion in the Phoenix system. Discusses invention and causes of the corrosion and the cost of repairs.


Durability of Clay Pipe

Vitrified Clay Pipe is unique in its corrosion and abrasion resistant qualities. It is manufactured from clays and shale's, the earthy mineral aggregates which the end products are yielded by the wea...


Energy Audit of Vitrified Clay Pipe Fabrication

This report summarizes results obtained during an investigation conducted by ITT Research Institute, under Project D8143, for the National Clay Pipe Institure (NCPI). Work on the program began in Jan...


Evaluating Ductile Iron Pipe Construction

The majority of ductile iron pipelines have only been in operation for 25 years or less. Failures of ductile iron piping have become more prevalent as the pipelines have gotten older. Experience has...


Excerpts From National Cooperative Highway Research Program Report Plastic Pipe For Subsurface Drainage of Transportation Facilities

This report focuses on the suitability of various plastic pipe systems for the drainage of highway and other transportation facilities. The authors relied on available information and experiences with...


Guidelines for Controlled Low Strength Material (CLSM) Mix Design, Placement and Testing for use as a Bedding Material for VCP

Controlled Low Strength Material (CLSM) is used as a bedding material for VCP to meet the requirements of ASTM C-12.


Hydrogen Sulfide Corrosion in Wastewater Collection and Treatment Systems

A report to congress on the effects of hydrogen sulfide on sewers.


Investigation of the Long-Term Creep Modulus for Buried Polyethylene Pipes Subjected to Constant Deflection

The tests which will be reported in this paper are simulating the stress relaxation in constantly deflected pipe rings of various high density and medium density polyethylene grades. The pipe rings a...


Load Bearing Characteristics of Bedding Materials for Sewer Pipe

National Clay Pipe Institute Research Laboratory began field studies to determine the effects of loads imposed on pipelines during backfilling and whether these loads either increase or decrease as a ...


Loads on Buried Rigid Conduit - A Ten Year Study

A paper reporting the development of load imposed by 12 ft (3.7 m) of sandy clay backfill (positive projecting embankment condition) on a buried 8-in. (200-mm) vitrified clay pipeline (Line 5) was pu...


Manning's Coefficient Calculated From Test Data

In general, the information on n values seems to indicate that the choice of a value should be such as to provide some margin of safety in design. The uncertainty of the values for n in-common use has...


Microtunneling Forces: The Pipe's Perspective

This paper reports a statistical method for calculating the maximum axial force required in microtunneling. Other forces put on the pipe when steered are discussed. A theoretical method is given for...


Optimal CLSM Mix Design

These tests were conducted to define the optimal mix for Controlled Low-Strength Material (CLSM) used in gravity sewer applications with vitrified clay pipe. Varying percentages of 3/8-inch coarse ag...


Pilot Tube Microtunneling Method and Case Study

Pilot Tube Microtunneling (PTMT) has been increasing in popularity year after year since it was first introduced in the United States in 1995. This guided-boring process has grown to become a replace...


Pilot Tube Microtunneling Project Parallels the Shore of Lake Erie in Toldeo Ohio: A Case Study

Pilot Tube Microtunneling (PTMT) has been increasing in popularity year after year since it was first introduced in the United States in 1995. This guided-boring process has grown to become a replace...


Sewer Main Collections System - University of Houston Study

While numbers of small to large older cities are undertaking repairs and maintenance, several other newer cities are planning on installing wastewater systems. Infiltration due to leaking pipes, man...


Static Pipe Bursting Using Vitrified Clay Jacking Pipe in Phoenix Soils: A Case Study

The City of Phoenix, Ariz., recently elected to perform two large pipe bursting projects; one of these projects utilized vitrified clay jacking pipe as the replacement pipe material. The notice to pr...


Tests on Slimed Sewers

This test evaluates slime layer development using various pipe materials in actual sewage flow conditions. Test showed that clay and PVC showed similar slime layer development.


The City of Atlanta: Microtunneling Projects Using Vitrified Clay Jacking Pipe

The City of Atlanta is in the process of completely overhauling the city’s water and sewer infrastructure in a period of only 10 years. Clean Water Atlanta is a $3.9 billion collection of projects an...


The Evolution of Jointing Vitrified Clay Pipe

Brief review of changes in the water treatment industry and how the clay pipe industry has changed its product to meet the changing attitudes. Chronicles the development of today's compression joint.


The Problem of Hydrogen Sulphide in Sewers

The definitive study by Dr. Richard Pomeroy, Ph. D. on the development and effects of hydrogen sulphide in sewer systems.


Using Historical Repair Data to Create Customized Predictive Failure Curves for Sewer Pipe Risk Modeling

Seattle Public Utitlities commissioned a study to develop customized failure curves based on recent experiential sewer pipe failure data. These new curves would be created using actual historical pipe...