Red Seal Plumbing Practice Exam

Propane cylinders are designed and manufactured to specific standards and specifications. The TC 39, 2P, and 2Q specifications refer to industry standards for the manufacturing of propane cylinders. Option A is incorrect because even though these cylinders are designed to be durable and long-lasting, they are not intended to be refilled indefinitely and should be replaced when they reach their expiration date. Option C is incorrect because special permits are not required to refill propane cylinders manufactured to these specifications. Option D is also incorrect because propane cylinders can be refilled by anyone who is licensed, trained, and follows appropriate safety procedures, not just the manufacturer. Therefore, the correct answer is B, as these cylinders cannot be refilled and should be safely disposed of when empty.