Chapter 11 - Plumbing Ventilation

portion of the drainage pipe installation, designed to maintain a balance atmospheric pressure inside the system to prevent trap seal loss, retardation of flow, and deterioration of the materials

ventilation

Ventilating a drainage system requires the natural laws of nature such as the principles of:

governing the atmosphere, gravity, siphon

• most common and serious problem being encountered in a drainage system

• inadequate ventilation of the trap and the subsequent minus and plus pressures inside the system

• when the water seal escape from the P-trap

trap seal loss

the result of minus pressure in the drainage system

siphonage

two class of siphonage

direct or self siphoning, indirect or momentum siphoning

occur in unventilated traps which serves as oval bottom fixtures like lavatories or slop sink

direct or self siphoning

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

• caused by plus pressure

  • water flow drops downward rapidly forming a slug like, the air inside the pipe will be compressed downward

back pressure

considered a minor proble, and is less probable to drain the water inside the trap

evaporation

a wind velocity passing over the top of the soil pipe may affect the trap seal

wind effect

• seldom happen, rarely experieced

  • draining of the water seal caused by foreign objects like thread or string suspended and extended over the outlet arm of the trap

capillary action

vent pipe used to ventilate the soil and waste pipes are the and ?

main soil, waste vents

the main vent and other subsidiary form of relief vents, are classified according to the functions they perform, and they are called and ?

relief, yoke vent

“All roof extensions of soil or waste stack shall run full size at least _ cm above the roof when the roof is used for other purposes than weather protection…”

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portion of the vent pipe system, serving as terminal for the smaller forms of individual and grounded fixture trap ventilation

• sometimes called?

main vent, collecting vent line

source through whih air is admitted to the plumbing systems

• means of eliminating objectionable odors

main soil vent

the drainage system is a combination of [ ], [ ], and [ ].

waste pipe, vent pipe, water supply

Individual vent is sometimes referred to as?

back vent

portion of the vent system that serves as a single trap

individual vent

“No vent shall be less than _ (in) diameter except for a [ ] (in) diameter waste pipe. The vent pipe shall be of the same diameter size as the waste pipe,…”

1.5, 1.25

is employed where to or more fixture traps are installed on a horizontal soil or waste branch

circuit or loop vent

“No more than _ water closets or other fixtures shall be allowed on any circuit or loop vent.”

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installed to ventilate the soil and waste pipe and the connecting branches rather than the fixture traps

relief vent

On a long vertical soil pipe, a Relief Vent is installed at 3 or 5 floor intervals. In this manner of installation, the relief vent is referred to as or ?

yoke, by-pass ventilation

• is on type of ventilation use on fixtures in a room away from partitions

  • common to beauty parlor, barber shop, dental clinic and operating room

looped vent

portion of the vent pipe system where liquid waste regularly flows

wet ventilation