What type of fuel dispensing hose is installed on a type 4 hose end pantograph?

The correct choice reflects the prescribed standards for fuel dispensing hoses installed on a type 4 hose end pantograph, which typically utilize flexible yet durable materials to ensure safe and efficient fuel transfer. A 3 inch API 1529 semi hard wall hose is designed to handle the specific requirements of aviation fuel dispensing, including pressure ratings and flexibility while maintaining a hard enough structure to prevent kinking or collapse during operation.

The API 1529 standard outlines specifications for aviation fuel handling, and the semi hard wall construction provides a beneficial balance of flexibility and resilience, making it suitable for applications where some degree of movement is expected. This type of hose effectively transports fuel while mitigating risks associated with wear and stress, which would be crucial during operations relying on a pantograph system.

In contrast, the other options cater to different requirements. The hard wall hoses might be too rigid and lack the necessary flexibility for a pantograph application, and the specifications of API 1581 focus on different contexts, which may not align with the typical needs of a type 4 hose end pantograph. Understanding these standards and their applications is essential in the selection process for fuel dispensing systems.