Discover the maximum safe air pressure, Mechanical Engineering

Discover the maximum safe air pressure:

A cylindrical compressed air drum is equal to 2 m in diameter along plates 12.5 mm thick. The efficiencies of the longitudinal (ηl) and circumferential (ηc) joints are equal to 85% & 45% respectively. If in the plating the tensile stress is to be limited to 100 MN/m2, discover the maximum safe air pressure.


The efficiency of the joint effect the stresses induced. For a seamless shell (with no joints), efficiency is equal to 100%. While the efficiency of joint is less than 100%, the stresses are enhanced accordingly.

Therefore, if η is the efficiency of a joint in the longitudinal direction, affecting the hoop stress, then the stress shall be given as,

σ h  =    pd/ (4t ×ηI)

Here, the diameter d = 2 m = 2000 mm.

Thickness, t = 12.5 mm.

Limiting tensile stress = 100 MN/m2 = 100 N/mm2.

Letting the circumferential joint which influences the longitudinal stress,

Pd/ (4t × ηl) = 100

p × 2000 / (4 × 12.5 × 0.45) = 100

 p = 1.125 N/mm2

Likewise, considering the longitudinal joint which influences the hoop stresses,

pd / (2t × ηc) = 100

p × 2000 / (2 × 12.5 × 0.85) = 100

p = 1.063 N/mm2

Evidently, safe pressure is governed through hoop stress.

Therefore, maximum safe air pressure = 1.063 N/mm2.

Posted Date: 1/21/2013 2:20:24 AM | Location : United States

Related Discussions:- Discover the maximum safe air pressure, Assignment Help, Ask Question on Discover the maximum safe air pressure, Get Answer, Expert's Help, Discover the maximum safe air pressure Discussions

Write discussion on Discover the maximum safe air pressure
Your posts are moderated
Related Questions
One end of a rod, 35 mm in diameter, is diped into a furnace with the other end projecting in the outer air. After the steady state is obtained, the temperature of the rod is evalu

What is wave? How many type of the waves?

Equation for principal stresses and principal planes: Derive equation for principal stresses and principal planes for the element subjected to compound stresses. Sol.:

Design a shaft to transmit power from a motor to a lathe head stock through a pulley by means of a belt drive. The pulley weighs 200 N and is located at 300 mm from the centre of t

Airport Layout: The main components of an airport are: (a)        Runways (b)       Taxiways (c)        Apron (d)       Terminal area (i)        Terminal build

Working of lacashire boiler: WORKIN G: Water is filled through feed check valve. On burning fuel over grate, the hot gasses are produced which move in flue gas tubes.

Split the harmonic motion x=10 sin (wt + 30 0 ) into two harmonic motions one having a phase angle of zero and the other of 45 0 . Describe and derive an expression for energy m

Company level - Safety Organization This is at company level and will straight report to the corporate director. He has to always monitor safety policies of the company and b