____ of a plumbing system, is that portion of the drainage pipe installation, designed to maintain a balance atmospheric pressure inside the system to prevent problems like:

1. Trap seal loss

2. Retardation of flow

3. Deterioration of the materials

• Ventilation

• Pressure valve

Among the most common and serious problem being

encountered in a drainage system is the ____.

_____ can be attributed to inadequate ventilation

of the trap and the subsequent minus and plus pressures

inside the system.

• Trap Seal Loss

• back pressure

_____ is the result of minus pressure in the drainage system. If the trap of a common seal is open and exposed to the atmosphere, both the inlet and the outlet orifices will be under balance atmospheric pressure. As such, the tendency of water seal to move is remote.

• Siphonage

• Back pressure

When the water seal escape from

the P-trap, it is called ____

• Trap Seal Loss.

• Self Siphoning

_____ occur in unventilated traps ,which serves as oval bottom fixtures like lavatories or slop sink. Self siphonage is created when a rapid flow of water passing through the pipe siphon down the water seal inside the traps with no vent provision.

• Direct or Self Siphoning

• Indirect or Momentum Siphoning

____ is the result of a minus pressure in the pipe created by heavy discharge of water from a fixture installed on a line serving another fixture at a lower floor.

• Indirect or Momentum Siphoning

• Self siphonage

_____ is caused by plus pressure. When large

amount of water flow drops downward rapidly forming a

slug like, the air inside the pipe will be compressed

downward.

• Back Pressure

• Indirect or Momentum Siphoning

In the absence of adequate ventilation, the

compressed air will be forced to find its away out through a weaker point. The trap seal being the weakest point, will give way and blow out of the fixture

• Back Pressure

• Evaporation

This process is considered a minor problem and is less probable to drain the water inside the trap.

however, happen only on floor drain which are not regularly used to admit water, but exposed to extreme temperature.

• Evaporation

• Wind Effect

A wind velocity passing over the top of

the soil pipe may affect the trap seal. This kind of trap seal

loss is one improbable thing to happen by removing the

entire water seal inside the P-irap.

• Wind Effect

• Capillary action