Exam Question
(a) State why double walled fuel pipes are employed for high pressure fuel lines. (6)
(b) Sketch and describe such a double walled pipe arrangement and show how high pressure pipe failure is indicated. (10)
Class 4 (4th Engineer)
MEKM
📅 Dec 2022
Reference Answer
### (a) Reasons for employing double-walled fuel pipes for high-pressure fuel lines (6 Marks)
Double-walled fuel pipes are a critical safety feature mandated by international regulations for high-pressure fuel oil delivery systems on marine diesel engines. Their primary purpose is to prevent the atomized spray of highly flammable fuel from reaching hot surfaces or ignition sources in the event of a primary pipe failure. The specific reasons are detailed below:
* **Fire Prevention (Primary Safety Concern):**
* **Risk of Atomized Spray:** High-pressure fuel lines operate at pressures typically ranging from 800 to over 2000 bar. A leak or rupture in such a pipe would result in fuel being sprayed out as a fine, atomized mist. This mist has a very large surface area-to-volume ratio, making it highly susceptible to spontaneous combustion or rapid ignition.
Double-walled fuel pipes are a critical safety feature mandated by international regulations for high-pressure fuel oil delivery systems on marine diesel engines. Their primary purpose is to prevent the atomized spray of highly flammable fuel from reaching hot surfaces or ignition sources in the event of a primary pipe failure. The specific reasons are detailed below:
* **Fire Prevention (Primary Safety Concern):**
* **Risk of Atomized Spray:** High-pressure fuel lines operate at pressures typically ranging from 800 to over 2000 bar. A leak or rupture in such a pipe would result in fuel being sprayed out as a fine, atomized mist. This mist has a very large surface area-to-volume ratio, making it highly susceptible to spontaneous combustion or rapid ignition.
Full answer on MeoMock — surveyor-grade reference answers for 7,000+ written exam questions.
Prepare on Android — MeoMock on Google Play