Which article deals with fixed electric heating equipment specific to pipelines and vessels?

The answer is correct because Article 427 of the National Electrical Code (NEC) specifically addresses fixed electric heating equipment used for pipelines and vessels. This article provides guidelines and requirements for installation, ensuring safety and proper functionality in environments where heating is necessary to maintain the integrity of fluids being transported through pipes or contained in vessels. Addressing issues like ambient conditions, temperature controls, and the prevention of freezing are essential in this context.

In contrast, other articles focus on different types of electrical installations or equipment. Article 425, for instance, deals with outdoor and indoor electric heating equipment, while Article 424 focuses more broadly on fixed heating equipment, which does not specifically cater to the needs of pipeline and vessel applications. Article 409 is concerned with industrial control panels, which again diverges from the specific focus on heating for pipelines and vessels. This distinction highlights why Article 427 is the relevant reference for this topic.