What is hydrostatic testing of cold water piping, and what is a typical requirement?

• A. Filling and pressurizing the system to a specified test pressure to check for leaks; typically 1.5 times operating pressure for a set duration as required by code.
• B. Draining and refilling the system to ensure clean water.
• C. Testing electrical grounding of pipes.
• D. Inspecting joints visually without pressure.

Answer: (A)

Hydrostatic testing of cold water piping means filling the pipes with water and then pressurizing the system to stress-test it for leaks and joints. The goal is to push the system beyond normal operating conditions so any weak spots will reveal themselves. A typical requirement is to pressurize the system to about 1.5 times the operating (design) pressure and hold that pressure for a set duration, as specified by the code or project specs, using clean water and ensuring air is vented. After the test, you relieve the pressure, drain the system, and proceed with normal operation.