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RESOURCES > FAQS/TECHNICAL BRIEFS
Air Testing of Installed PVC Pipelines

It is common practice to pressure test installed pipelines to ensure that the pipe materials and installation are satisfactory. In fact, it makes sense that every installed pipeline be pressure tested to ensure a leak-free system.

Air Valves: Improving the Performance of Pressure Pipelines

Air valves automatically release or admit air during the filling, operation, or draining of a pipeline. For all pipe materials, efficient and safe pipeline operation is dependent on continuous removal of air from the line.

 

Backfill Requirements for PVC Pressure and Gravity Pipes

PVC pressure pipe can be installed without special backfill, since external loads are not design-limiting. For PVC gravity sewer pipe, on the other hand, backfill material and compaction are key components of design.

Changing Direction: Axial Joint Deflection Explained

To achieve a change in direction (vertical, horizontal, or a combination of both), one method is axial deflection of the gasketed pipe joints. This is appropriate where gradual changes in direction are planned without bending the pipe barrel.

Cold weather: no practical effect on pvc pipe installation and use

Fifty years of field experience confirm that PVC pipe more than measures up to the rigors of cold-weather installation and use. In fact, an easy-to-use product like PVC pipe becomes even more advantageous as temperatures decrease. PVC is widely used in Canada, Minnesota, and the Dakotas, so cold weather is not a limiting factor for PVC pipe projects.

DESIGN FACTOR AND SAFETY FACTOR EXPLAINED
Recent changes to AWWA standards have introduced confusion to the concepts of design factor (DF) and safety factor (SF). This document clarifies the relationship between the two terms.
Dimension Ratio (DR) Explained for PVC Pipe

Dimension ratio is an important but often misunderstood concept for PVC pipe. Some of the confusion arises because of the use of both "Dimension Ratio" (DR) and "Standard Dimension Ratio" (SDR) in product standards.

Expansion Gaps for Gasketed PVC Pipe: Maximizing Joint Performance

Video inspections of PVC sewer pipelines often reveal small longitudinal gaps between the spigot end and the bell shoulder of the gasketed joints. These gaps are not flaws. In fact, gaps are an important design consideration for both pressure and non-pressure PVC pipes.

Gasketed PVC Pipe: The Importance of Insertion Lines

The insertion line found on gasketed PVC pipe – marked around the pipe circumference near the spigot end – indicates the depth of insertion of the pipe spigot into the bell. The line is positioned by the pipe manufacturer based on bell design, allowances for manufacturing tolerances, and anticipated thermal expansion and contraction.

joint restraint options for pvc pipe

Joint restraint is used to prevent movement of pipe, fittings, or appurtenances in response to pressure-pipe thrust forces. Restrained joints are also necessary for trenchless installation.

Looking Back 20 Years at AWWARF’s 1994 Study on PVC Water Pipe Performance

A look back at AWWARF’s 1994 study on PVC water pipe performance and its findings regarding PVC pipe’s strength over time, tapping, UV exposure, chemical permeation, etc. 

MARKING REQUIREMENTS FOR PVC WATER AND SEWER PIPE
Product standards for PVC pipe require specific information to be continuously printed on each length of pipe. The information provides details about the pipe material, manufacture, and testing, as well as the appropriate logo of any certification agency.
Pipe Stiffness Explained - PVC and Ductile Iron

Some specifiers choose Ductile Iron pipe due to its “strength” in resisting external loads. This was true in the good old days of thick-walled DI Class pipe, but now the thinned-down walls of DI Pressure Class pipe have made PVC the stronger option.

PVC Pipe Excels in Deep Bury Applications

Some engineers mistakenly contend that PVC pipe is not suitable for deep-bury projects. The concern is that the pipe will not hold up under large earth loads. However, installations throughout North America have shown otherwise and have demonstrated that PVC pipelines perform long-term at depths of more than 40 feet.

PVC Pipe Materials: Cell-Class ExplaineD

Product standards for PVC municipal pipes require that the PVC materials meet ASTM D1784 cell-class requirements. The cell class consists of five numbers – this tech brief discusses the concept of cell class and what the numbers mean. 

PVC Pressure Pipe – Not Subject to Collapse from Fire-Flow Pumping

Some pipeline designers mistakenly contend that PVC pipe must be DR18 or thicker to resist collapse due to vacuum caused by fire-flow conditions. This technical brief refutes that misconception.

PVC PRESSURE PIPE: DEFINING “LARGE-DIAMETER”

The term “large-diameter” is not well-defined – in fact, what was considered a large PVC pressure pipe has changed over the years. The attached tech brief provides clarification on the topic.

SAFETY FACTORS FOR AWWA PLASTIC PIPES: WHAT ENGINEERS SHOULD KNOW

The 1.6 SF proposed for C906 falls outside the conservative tradition for AWWA standards for transmission/distribution pipe that has served North American utilities well. The PVC Pipe Association recommends that design engineers recognize this disparity and continue to use a SF = 2.0 for their projects.

 

Solid-Wall PVC Gravity Sewer Pipe: defining “Large-Diameter”

The term “large-diameter” is not well-defined – in fact, what was considered a large PVC sewer pipe has changed over the years. The attached tech brief provides clarification on the topic. 

Update on ASTM F679 Standard for Large-Diameter PVC Sewer Pipe

The ASTM F679 standard has been revised to eliminate the “T1” and “T2” wall-thickness designations, yet many municipal specifications still include the “T” call-outs. The attached tech brief discusses the current standard and how project specifications can be revised to harmonize with the standard.

UV Exposure HAS No Practical Effects on PVC Pipe Performance

Ultraviolet (UV) radiation from sunlight can affect the outermost surface of PVC pipe. However, even after prolonged exposure, there are no practical effect on PVC pipe’s performance characteristics...

 

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