Practical Project Management for Building and Construction

Knowledge Areas  •  241

bunker. is will happen if both the pressure-reducing valve and safety

valve fail the same month. e probability of this is once every 1,800

years—(1/120) × (1/180) = 1/21,600, which is once in 21,600 months (1,800

years). If the blast disc does not work, the gas and solvent blow into shas

and the oce area.

In this example, it is not acceptable that 20 million liters of N

2

can ow

out once every 10 years. erefore, a second pressure reducing valve is set

up as shown in the gure. e probability of emptying the tank will then

be once in 1,200 years (1/120) × (1/120) = 14,400 months and that the gas

and solven ...