Direct service tapping of operating cast and Ductile iron piping systems has been a common practice for more than 100 years. Ductile iron pipe can be readily field cut and tapped to fit normal and emergency situations.

Direct Service Connection Installation Comparison: Ductile Iron Pipe vs. Polyethylene Pipe

This technical publication reports on tests comparing direct tapping of Ductile Iron pipe with sidewall fusion of service connections on polyethylene pipe. Time, internal pressure, material strength, and other factors of both materials were compared with respect to tapping.

DIPRA conducted tests comparing the direct tapping of Ductile iron pipe and polyvinyl chloride pipe. Cost, time, internal pressures, material strength, and other factors were also compared with respect to tapping. All tests were conducted using prescribed procedures for each material.

Tests reported herein reaffirm that Pressure Class 350 Ductile iron pipe can be direct-tapped with confidence and that the resultant thread engagement is more than adequate to effect a watertight seal. Read the publication to learn more.

Ductile iron pipe is not prone to permeation and the resulting contamination of drinking water that may result, whereas plastic pipe is susceptible to permeation that can damage the pipe and contaminate the water. In fact, in a study prepared for the EPA, plastic pipe was involved in 98% of permeation incidents. According to the EPA’s website, “The major sources of vinyl chloride in drinking water are leaching from PVC piping and the discharge from plastics factories. Some people who drink water containing vinyl chloride well in excess of the maximum contaminant level (MCL) for many years may have an increased risk of cancer.” The EPA’s maximum contaminant level goal (MCLG) is zero.