The principal causes of explosions, in fact the only causes, are deficiency of strength in the shell or other parts of the boilers, over-pressure and over-heating.
Deficiency of strength in steam boilers may be due to original defects, bad workmanship, deterioration from use or mismanagement." "Cause.-Boiler explosions are always due to the fact that some part of the boiler is, for some reason, too weak to withstand the pressure to which it is subjected.This may be due to one of two causes: Either the boiler is not strong enough to safely carry its proper working pressure, or else the pressure has been allowed to rise above the usual point by the sticking of the safety valves, or some similar cause" Boiler explosions are common in sinking ships once the superheated boiler touches cold sea water, as the sudden cooling of the superheated metal causes it to crack; for instance, when the SS Ben Lomond was torpedoed by a U-boat, the torpedoes and resulting boiler explosion caused the ship to go down in two minutes, leaving Poon Lim as the only survivor in a complement of 54 crew.Źródło: https://en.wikipedia.org/wiki/Boiler_explosion#Causes_of_boiler_explosions
More work done in a block must be well organized in such a way that it can be performed as soon as possible with the greatest respect for the rights of the people to preserve their privacy and quiet in the early morning.The tasks of the executives of the association must also ensure the safety of residents of the block during the works. They can apply to do the second division of water, clean water and sewage network or even replacement of water meters in all areas.
Plastic Pipes are classified by their ring stiffness.
The preferred stiffness classes as described in several product standards are: SN2, SN4, SN8 and SN16, where SN is Nominal Stiffness (kN/m2).
Stresses and strains caused by the deflection of the pipe will occur within the pipe wall.
However, the induced stresses will never exceed the allowed limit values. The thermoplastic behavior of the pipe material is such that the induced stresses are relaxing to a very low level.It has to be noted that induced strains are far below the allowable levels. This flexible behaviour means that the pipe will not fail.
It will exhibit only more deflection while keeping its function without breaking. However, rigid pipes by their very nature are not flexible and will not follow ground movements.They will bear all the ground loadings, whatever the soil settlement.
This means that when a rigid pipe is subject to excessive loading, it will reach the limit for stress values more quickly and break. It can therefore be concluded that the flexibility of plastic pipes is such that it offers an extra dimension of safety.Buried Pipes need flexibility9Źródło: https://en.wikipedia.org/wiki/Plastic_pipework#Flexibility.