What does the LNG cargo pumps capacity...

🔍 Key Concepts

• Relationship between pump capacity (flow rate) and back pressure in centrifugal-type cargo pumps used on gas carriers • Effect of liquid density on the developed head and actual volume flow from a pump • Whether pump speed is actually variable or fixed for typical LPG/LNG deepwell and submerged cargo pumps

💭 Think About

• For a given pump running speed, think about which factors in the system (cargo properties and line conditions) could reduce or increase the actual delivered flow rate • Consider how a centrifugal pump’s characteristic curve changes (or doesn’t change) with liquid density and with discharge pressure • Ask yourself: if you keep the pump’s RPM constant, can changes in cargo type or line pressure change the capacity actually achieved on board?

✅ Before You Answer

• Verify how back pressure (manifold pressure, static head, line resistance) affects the operating point on a pump curve • Check whether density of cargo changes the volume flow, the pressure head, or the power requirement for the same pump • Confirm if LPG/LNG cargo pumps in exam context are normally treated as constant-speed pumps, and what that implies for which variables still influence capacity

What does the LNG cargo pumps capacity depends upon?

density of cargo

speed (LPG/LNG pumps are constant speed)

back pressure

All of the above

🔍 Key Concepts

💭 Think About

✅ Before You Answer