Answer:
A relief valve is either in the pressure reducer or in the downstream side of the system to ensure that the control air pressure does not exceed about 30 psig.
Answer:
The minimum value of wall thickness t=3.63 mm.
Explanation:
Given:
D=200 mm
P=4 MPa
t= Wall thickness
maximum shear stress=27.5 MPa
We know that
hoop stress 
Longitudinal stress
So maximum shear tress in plane

Now by putting the value

So t=3.36 mm
The minimum value of wall thickness t=3.63 mm.
Answer:
Pressure = 115.6 psia
Explanation:
Given:
v=800ft/s
Air temperature = 10 psia
Air pressure = 20F
Compression pressure ratio = 8
temperature at turbine inlet = 2200F
Conversion:
1 Btu =775.5 ft lbf,
= 32.2 lbm.ft/lbf.s², 1Btu/lbm=25037ft²/s²
Air standard assumptions:
= 0.0240Btu/lbm.°R, R = 53.34ft.lbf/lbm.°R = 1717.5ft²/s².°R 0.0686Btu/lbm.°R
k= 1.4
Energy balance:
As enthalpy exerts more influence than the kinetic energy inside the engine, kinetic energy of the fluid inside the engine is negligible
hence 

= 20+460 = 480°R
= 533.25°R
Pressure at the inlet of compressor at isentropic condition

=
= 14.45 psia