Marine hand pumps are important liquid delivery equipment in ships, commonly used for pumping oil, fresh water and other liquids. Evaluating the flow and pressure performance of hand pumps is essential to ensure the safe and efficient operation of ships. The following are some key steps and considerations for evaluating the flow and pressure performance of pumps.

1. Flow performance evaluation
Flow definition
-Flow refers to the volume of liquid passing through the pump per unit time, usually expressed in liters per minute (L/min) or cubic meters per hour (m³/h).
Measurement method
-Calibration test: The flow rate is determined by measuring the volume of liquid output by the pump in a known time. The pumped liquid can be collected in a container and the time can be recorded to calculate the actual flow rate.
-Flow meter: Use a flow meter to directly measure the flow rate of the pump. This method is more accurate and suitable for long-term use.
Influencing factors
-Pump structural design: The flow capacity of the pump is closely related to its internal structure (such as piston diameter, stroke length).
-Liquid viscosity: The viscosity of different liquids affects fluidity and thus the flow rate.
-Operation speed: The operation frequency of a hand pump is directly related to the flow rate, and frequent operation usually increases the flow rate.
2. Pressure performance evaluation
Definition of pressure
-Pressure refers to the liquid pressure that a pump can generate when it is in operation, usually expressed in bar or kPa.
Measurement metho
-Pressure gauge test: Install a pressure gauge at the outlet of the pump, manually operate the pump and record the pressure gauge reading to determine the working pressure of the pump.
-Load test: Connect a load of known pressure (such as a water column) to the outlet of the pump to observe the pressure performance of the pump under different operating conditions.
Influencing factors
-Pump design: Different types of manual pumps (such as gear pumps and piston pumps) have different pressure generation capabilities.
-Liquid properties: The density and viscosity of the liquid will affect the pressure output of the pump. Liquids with higher viscosity usually require higher pressure to be pumped smoothly.
-System resistance: The length and diameter of the connecting pipe, valves and other accessories will increase the flow resistance, thereby affecting the pressure performance.
3. Evaluation in actual application
In actual application, flow and pressure performance should be considered comprehensively. For example:
-Evaluate the required application: Determine the required flow and pressure standards based on the type of pumped liquid and specific tasks (such as emergency drainage, oil delivery, etc.).
-Use environment: Consider the impact of different sailing conditions (such as waves, tilt, etc.) on the pump performance of the ship to ensure that the selected pump can work reliably under various conditions.
4. Choose a suitable pump
Based on the evaluation results, when choosing a suitable marine manual pump, pay attention to the following points:
-Flow and pressure matching: Ensure that the performance of the pump can meet actual needs.
-Material and durability: Consider the manufacturing material and corrosion resistance of the pump to adapt to the marine environment.
-Portability and operability: The design of the hand pump should be easy to operate and maintain, and suitable for use by crew members under different conditions.