$442P\frac{a}{m}$

$350P\frac{a}{m}$

$4-$ Diameter of steel pipe for section A$-$B:$*$

$25mm$

$32mm$

$40mm$

$35mm$

$5-$ Diameter of steel pipe for section $f-g^{**}$

$25mm$

$20mm$

$32mm$

$23mm$

The given figure represents a two$-$pipe reverse retum hot water heating system. The heating load for the system radiators is as follows. The supply hot water temperature drop is $10C$ and the total equivalent length of circuit $(1)$ is $130m.*1-$ The total heating load for the boller $Qb$ :

$\backslash$table$[[$Radiator M$,1,2,3,4,5,6,7,8,9],[$Load $($kW$),3\mathrm{.}20,2\mathrm{.}10,2\mathrm{.}67,3\mathrm{.}20,2\mathrm{.}40,2\mathrm{.}67,2\mathrm{.}14,4\mathrm{.}00,2\mathrm{.}40],[$Radiator M$,10,11,12,13,14,15,16,17,],[$Load $($kW$),2\mathrm{.}67,3\mathrm{.}20,2\mathrm{.}10,2\mathrm{.}40,4\mathrm{.}60,2\mathrm{.}67,2\mathrm{.}14,1\mathrm{.}60,]]$

$27\mathrm{.}36kW$

$50\mathrm{.}12kW$

$4556kW$

$24\mathrm{.}87kW$

$2-$ The required pump capacity is:$"$

$1\mathrm{.}1\frac{L}{s}$

$1$ and $4$

$0\mathrm{.}65\frac{L}{s}$

$1\mathrm{.}1k\frac{g}{s}$

$|$

$3-$ The pressure drop per unit length. If an iron and bronze pump is to be used:$*$

$20000P\frac{a}{m}$

$240P\frac{a}{m}$