Physical Address
304 North Cardinal St.
Dorchester Center, MA 02124
D2143-21 – Standard Test Method Technical Guide
📐 Scope and Summary of Test Method
ASTM D2143-21, Standard Test Method for Cyclic Pressure Strength of Reinforced, Thermosetting Plastic Pipe, provides a procedure for evaluating the failure characteristics of reinforced thermosetting resin pipe (RTRP) under repetitive internal hydraulic pressure loading. The test method is specifically applicable to pipe with an outside diameter to wall thickness ratio of 10:1 or greater.
Specimens are exposed to cyclic internal pressures at several distinct stress levels. The number of cycles required to reach failure is recorded at each level to characterize the material’s fatigue behavior. Test temperatures are achieved by circulating a suitable medium, specified as either salt water or municipal water, through the specimen during the test sequence.
Values stated in inch-pound units are the standard within this method; metric equivalents are provided for reference only.
⚠️ Specimen Rejection Criterion: Any test specimen that fails within one pipe diameter of the end closure must be discarded (Section 3.1.1). Such failures are typically induced by the stress concentration of the end seal, rather than the inherent strength of the pipe wall.
⚙️ Terminology, Failure Detection, and Key Specifications
The standard defines distinct failure modes and relies on an electronic monitoring system for precise detection.
| 🟦 Failure Type | 📏 Definition |
|---|---|
| 🧩 Localized Leaking | One or more small fractures permitting test fluid transmission at a measurable rate. |
| 💦 Weeping | General transmission through the wall without visible fracture; may appear as moisture condensation. |
| 💥 Wall Fracture | A complete break in the pipe wall causing immediate, total loss of test fluid. |
The failure detector measures the electrical resistance between the conductive test fluid and a conductive wrap (e.g., metallic foil) placed around the specimen. A failure event is triggered when the resistance drops, or for municipal water, when the first drop of fluid breaches the wall.
| 📐 Parameter | 🎯 Specification |
|---|---|
| 🟦 Pipe Ratio | OD/Wall ≥ 10:1 |
| ⚡ Detector Threshold | Resistance decrease to 10 – 20 MΩ |
| 📏 Valid Failure Zone | More than 1 diameter from end closure |
💡 Significance and Quality Control: The regression characteristics derived from this method help establish the fatigue resistance of a pipe material. Once established, a single pressure level can be used for routine quality control (Section 5.2). Results are applicable only to conditions that specifically duplicate the procedures used (Section 5.1).
Supporting reference standards for this test method include Practice D618 for conditioning, Practice D2992 for obtaining hydrostatic design basis, and Practice D3567 for measuring pipe dimensions.
❓ Frequently Asked Questions
🔍 What constitutes a failure under this standard?
A failure is defined as any transmission of the test fluid through the pipe wall, whether through wall fracture, localized leaking, or weeping, provided it occurs more than one pipe diameter from the end closure.
💡 What is the required pipe geometry for this test?
According to Section 1.1, the test method is limited to pipe in which the ratio of the outside diameter to the wall thickness is 10:1 or more.
⚡ How does the failure detector function?
The device monitors electrical resistance between the test fluid (a conductor) and a conductive wrap on the pipe. Failure is indicated when the resistance drops to a range of 10 to 20 meg-ohms, or for municipal water, when the first drop of fluid passes through.
📌 Is there an ISO equivalent to ASTM D2143?
Note 1 of the standard clearly states: “There is no known ISO equivalent to this standard.”
✅ Summary: All technical values, including the 10:1 pipe ratio, the 10–20 MΩ detection threshold, the rejection criterion (>1 diameter from end closure), and the designation of inch-pound units as standard, are derived directly from the text of ASTM D2143-21.