How to choose a pump
Checklist published on the original Funwella news page.
The original article is short and practical. It asks the buyer to lock six things before talking about a model number.
Medium. Air means you must say whether you need positive pressure or negative pressure. Liquid means you must name the fluid — water, alcohol, cleaning fluid or another medium.
Use environment. Temperature and humidity are called out. Several Funwella water-pump tables already print 0–50 °C and 75% RH.
Flow. Separate no-load flow from load flow, and say whether the device needs a tight tolerance.
Pressure. Maximum pressure, working pressure, and suction head / head are listed as distinct numbers. Vacuum listings on this site use kPa (for example −60 kPa and −80 kPa).
Electrical. Rated voltage and start voltage. Funwella pages commonly list 3 V / 4.5 V / 6 V / 12 V / 24 V.
Air tightness and pressure hold. If the device must keep vacuum after the pump stops, say so in the RFQ.