Here is the report that I have for your inputs:

Pipe pressure drop calculator CALCULATION REPORT

1. volume flow rate (q): q = 8.040907 gpm US

2. weight flow rate (w): w = 58.381325 lb/min

3. pipe length (L): L = 192 ft

4 pipe diameter (D): D = 0.75 in

5. pipe roughness (kr): kr = 0.01 mm

6. density (ρ): ρ = 870 kg/m3

7. kinematic viscosity (ν): ν = 0.68 cSt

8. dynamic viscosity (μ): μ = 5.916E-004 Pas

9. K factor - minor lossed coefficient (K ): K = 0.0

10. velocity (V): V = 1.7798676 m/s

11. cross section area (A): A = 285.02295 mm2

12. friction coefficient (f): f = 0.021173518

13. Reynolds number (Re): Re = 49862.465

14. boundary layer (δ): δ = 0.09259989 mm

15. pressure on the pipe start (p1): p1 = 25 psi

16. pressure on the pipe end (p2): p2 = 12 psi

17. pressure drop (p1-p2): p1-p2 = 13 psi

Important things are - pressures are absolute - if not please use calculator and enter absolute values.

If you have no obstacles in pipe than K = 0. If not you must know number of elbows tees reducers valves pipe entrance and pipe exit.

You have all resistance coefficients at:

http://www.pipeflowcalculations.com/resistancecoefficientK/Kr for stainless pipe I used 0.01 mm.

Used calculator is at:

http://www.pipeflowcalculations.com/pressuredrop/