A loose type flange is to be designed with a tongue$-$and$-$groove flange facing with $1\mathrm{.}8$ m outside dia and $0\mathrm{.}018$ thickness $($go$).$ Other specifications are:

$1.$ Design Temp $=200-$Celsius

$2.$ Design pressure $=2$ MN$/$M$^2$

$3.$ Allowable stress of flange material $=120$ MN$/$m$^2$

$4.$ Allowable stress of bolting material $=100$ MN$/$m$^2$

$5.$ Gasket material: Vegetable fibre

$6.$ Ratio of gasket Internal dia to shell outside dia$=1\mathrm{.}01$

$7.$ Weld joint efficiency factor $=1$

a$.$ Calculate effective gasket width

b$.$ Calculate minimum Bolting area

$(4$ Marks$)$

c$.$ Estimate the bolt circle dia for M$39$x$3$ where gi$=1\mathrm{.}5$go