The first one defines fluid flow at one point where pressure is P1, velocity is ​v​1, and height is ​h​1. The second equation defines the fluid flow at another point where pressure is P2. Velocity and height at that point are ​v​2 and ​h​2. Define the pressure and flow rate.

Calculating force and area using the pressure equation

1. First convert 150 kPa to Pa:
2. 150 × 1,000 = 150,000.
3. Next substitute the values into the equation:
4. force normal to a surface area = pressure × area of that surface.
5. force = 150,000 × 180.
6. force = 27,000,000 N.

When a force is applied perpendicular to a surface area, it exerts pressure on that surface equal to the ratio of F to A, where F is the force and A the surface area. Hence, the formula for pressure ( p ) is p = F / A.

This will give you your flow rate in litres per minute (e.g. 0.4 litres x 10 = 4 litres per minute). As it is under 10 litres (1 bar) at 4 litres a minute, it is a low pressure system at 0.4 bar.

LPM is an abbreviation of litres per minute (l/min). When used in the context of a particle counter’s flow rate, it is a measurement of the velocity at which air flows into the sample probe. For example, a flow rate of 2.83 LPM means the particle counter will sample 2.83 litres of air per minute.

pascal

It is also given as inches of water gauge (iwg or in. w.g.), inches water column (inch wc or just wc), inAq, Aq, or inH2O. The units are conventionally used for measurement of certain pressure differentials such as small pressure differences across an orifice, or in a pipeline or shaft.