CWEA Collection System Maintenance (CSM) Certification Grade 2 Practice Test

A mandrel is a tool specifically designed for inspecting the interior of flexible conduits, such as those used in sewer systems. Its primary purpose is to test for excessive deflection, which can indicate structural issues or blockage within the conduit. The mandrel is inserted into the flexible conduit, and if it passes through without resistance, it signifies that the conduit maintains an acceptable shape and size. If the mandrel encounters resistance or cannot pass through, this suggests that there may be excessive deflection or other impairing features inside the conduit that need to be addressed.

In contrast, measuring flow rates involves the use of flow meters or other hydraulic measurement tools, while cleaning sewer lines typically requires other types of equipment, such as jetters or rods. Measuring pipe diameter is done using calipers or tape measures, not mandrels. The use of a mandrel is thus specific and critical in ensuring the integrity and functionality of flexible conduits in a collection system.