Question

The pressure in a water line is 1500 kpa. what is the line pressure in (a) lb/ft2 units and (b) lbf/in2 (psi) units?

Answer 1

a) 1500 kpa = 31,328.3208 lb/ft2

b) 1500 kpa = 217.5 psi

Step-by-step explanation:

This question can be solved using proportionality, that is, simple rules of three.

We have that:

Pressure of water line: 1500 kpa

(a) lb/ft2 units?

Each lb/ft2 is 0.04788 kpa. So

1 lb/ft2 - 0.04788 kpa

x lb/ft2 - 1500 kpa

`0.04788x = 1500`

`x = (1500)/(0.04788)`

`x = 31328.3208`

So

1500 kpa = 31,328.3208 lb/ft2

(b) lbf/in2 (psi) units?

Each kpa is 0.145psi. So

1 kpa - 0.145 psi

1500 kpa - x psi

`x = 1500*0.145`

`x = 217.5`

So

1500 kpa = 217.5 psi

Answer 2

To solve this problem, we know that:

1 psi = 6894.76 Pa

1 lb / ft^2 = 47.88 Pa

Therefore:

a. 1500 x 10^3 Pa * (1 lb / ft^2 / 47.88 Pa) = 31,328.32 lb / ft^2

b. 1500 x 10^3 Pa * (1 psi / 6894.76 Pa) = 217.56 psi