Pipe insulation should be inspected and maintained regularly to ensure optimal performance and prevent energy losses. The frequency of inspection and maintenance depends on factors such as the type of insulation, environmental conditions, and system usage. As a general rule, pipe insulation should be inspected every 6-12 months, and any damaged or deteriorated insulation should be replaced promptly. Additionally, engineers should ensure that the insulation is properly installed and secured to prevent damage or dislodgement over time.