How to solve

$11\mathrm{.}7$ A liquid refrigerant flows through the system, shown in Fig. P$11\mathrm{.}7,$ at the rate of $1\mathrm{.}70\frac{L}{m}in.$ The refrigerant has a specific gravity of $1\mathrm{.}25$ and a dynamic viscosity of $3{10}^{-4}Pa*s.$ Calculate the pressure difference between points A and B$.$ The hydraulic tube is drawn steel, with an outside diameter $($OD$)$ of $15$ mm $,$ a wall thickness of $1\mathrm{.}5$ mm $,$ and a total length of $30$ m $.$

FIGURE P$11\mathrm{.}7$ Refrigerant tubing for Problem $1$