APPRECIATION

Assalamualaikum…

Praise is presented only for ALLAH Almighty Disposer of all things. Peace and

blessings be upon beloved Prophet Muhammad leaflets bearing the revelation to

illuminate be universe, the companions, his family, all the scholars and lovers of Islam

throughout the world.

Thank to God that, I can complete the assignment on the end of chapter problem

about how to prevent loss water seal to be handed over to Mr. Huzaime b. Abd. Hadi

very well. By making this assignment I can add my knowledge.

Finally, we thank the lecturers who taught me, Mr. Huzaime b. Abdul Hadi has

been providing guidance and information on how to produce this work. Thank also to

friends who also give me lessons and share ideas and information.

INTRODUCTION

The loss of a trap seal will usually result in foul and objectionable gases and

odours entering a building from the system of discharge pipework. These gases will at

least be a nuisance and in extreme cases create a health hazard to the occupants of

the building. It is for these reasons that much importance is placed upon retention of the

water seal in all trap.

Trap seal may be lost in several ways. Some reasons may be attributed to bad

system design or installation techniques. Others are more natural or the result or

particular cimcumstances which may cause the loss of water seal, the common

circumstances are self siphonage, induce siphonage, back pressure, capillary attraction,

wavering out, evaporation, momentum and leakage.

HOW TO PREVENT THE PROBLEM

1) Self Siphonage

This is caused by a moving plug or charge of water running out of a steep-sided

sanitary appliance such as a wash basin. The plug of water moves through the trap,

pushing the air on the outlet side of trap in front of it, thereby creating a partial vacuum

in the branch discharge pipe which causes siphonage to occur and loss of the trap seal.

The technical term for the partial vacuum or negative pressure zone is ‘hydraulic jump’

as ilustrated in Figure 1 and 2 Self siphonage. Self siphonage of a trap usually indicated

by an excessive amount of noise as the sanitary appliance discharge its final quantity of

waste water.

Figure 1 Self siphonage.

Figure 2 Self siphonage.

Figure 3 Example of basin waste where self siphonage may occur.

How to prevent :

Self siphonage is usually prevented by one or more of the following:

1. By fitting a P trap to the sanitary appliance (thus avoiding vertical branch

discharge pipes).

2. Ensuring that the branch discharge pipe length and slope do not exceed

those recommended.

3. By fitting a ventilating or anti-siphon pipe adjacent to the trap outlet.

4. By fitting a larger diameter branch discharge pipe to the trap outlet.

5. By correct design of sanitary appliance.

6. By fitting a resealing or anti-siphon trap to the sanitary appliance.

2) Induce Siphonage

This is caused by the discharge of water waste from one sanitary appliance,

pulling or siphoning the seal of a trap of another appliance connected to the same

branch discharge pipe. This form of siphonage is most common in buildings where

ranges of appliances are fitted or where it is necessary to connect several appliances to

a common branch discharge pipe. The main causes of induced siphonange are poor

system design, inadequate pipe sizes or bad installation techniques.

Figure 4 Induced siphonage.

Figure 5 Induced siphonage.

Figure 6 Trap with induced siphonage.

How to prevent :

Some ventilation of the system may be required if induced siphonage is to be

prevented.

3) Compression or Back Pressure

Compression of air at or near the base of a discharge pipe may occurs as shown

in Figure 7. As water flows down a vertical stacks it takes some air with it. As this water

changes direction at the base of the stack (from the outside of the vertical pipe to the

invert of the near-horizontal drain pipe) the pipe bore becomes momentarily full of

water, so preventing the free flow of air up and down the discharge stack.

Figure 7 Compression or Back Pressure

Figure 8 Example of back flow into bath.

How to prevent :

Under these conditions a hydraulic wave is formed and air at the base of the

stack is compressed by a water falling from above, thus creating air pressure in excess

of atmospheric pressure. This pressure will attempt to escape through any branch

discharge pipe connected in the compression zone, thus blowing the seal of the trap

and allowing foul air from inside the discharge pipework to enter the building. Often the

displaced water will run back into the trap to form a seal but continued blowing of the

seal will cause a noise nuisance and allow foul gases into the room where the appliance

is fitted. Compression and back pressure are prevented by not fitting small or sharp

radius bends or having branch discharge pipes connected near to the base of a

discharge stack. Correct practice is to fit large radius bends and to ensure inlet

connections are not made close to the base of the stack.

4) Capillary Attraction

Loss of seal by capillarity occurs when a piece of porous material such as

threads or string from a mop or dishcloth are deposited into the water seal and over the

outlet invert of a trap as shown in figure 9, this will most commonly happen to

appliances such as kitchen or cleaners sinks fitted with S pattern traps.

Figure 9 Capillary Attraction

How to prevent :

Capillarity is prevented by regular cleaning of the inside of the trap and branch

discharge pipe or by laying a loose mesh strainer into the waste fitting of the appliance

to catch and retain loose porous strands which may be contained in certain types of

waste water.

5) Wavering Out

The effect of a high-velocity fluctuating wind passing over the top of an exposed

discharge stack ventilating pipe (see figure 10) will create varying air pressures and

draughts within the pipework system which may cause trap seals to fluctuate or waver,

resulting in loss of water from the seal.

Figure 10 Wavering Out

How to prevent :

Fluctuating, pressures caused by wind are best prevented by locating the vent

terminal position away from exposed locations and ensuring that a terminal grating is

fitted to all ventilating pipework.

6) Evaporation

This occurs usually in traps connected to sanitary appliances which are not used

regularly or where the ambient temperatures are relatively high. Evaporation is more

usual in the summer month when temperatures are higher or when buildings are left

empty or unattended due to holiday periods.

7) Momentum

The most usual cause of lossof trap seal by momentum is when quantity of water

is quickly discharged into a gully or washdown WC pan and the discharging water

carries away the water forming the trap seal.

8) Leakage

Trap occasionally loose their seals due to a leak on the fitting bellow water-seal

level. The leak may be due to a loose or badly jointed access bowl or cleaning eye or in

the case of soft materials, caused by impact resulting in fracture and damage to the trap

body.

Expertise in need of repair leakage

The work to repair the leak involves two tasks that require expertise:

1. Determine the cause and location of the leak.

2. Techniques and rules of waterproof material installed correctly.

The material used is known as water-resistant material or material

Waterproofing. This water-resistant material widely available in the market with different

brand names depending on manufacturer and distributor of such materials. Use of

fishing gear, equipment and means of proof is installed will determine the quality of

water proof work.

How can happen release

Unwanted leakage occurs. However it can occur in places and at unexpected

times. Leaks are a form of defects in the building and it can be caused by several

factors:

1. Construction design.

2. Low Mutukerja during construction.

3. Durability of materials.

4. The influence of the environment.

5. Lack of maintenance activities.

6. The use of the building, misconduct and external pressures.

Must be corrected release

Leak repair is the need to premises / building:

1. Meet the real purpose of the premises / building constructed.

2. Extend the economic life of the premises / building.

3. Reduce the potential for damage to buildings or equipment which caused

disruption to building operations.

4. Maintain the market value.Maintain the aesthetic value.

5. Increase worker productivity.

6. Ensure the safety and comfort of residents.

7. Meet the legal requirements of the building.

CONCLUSION

In conclusion, to complete the task, I can find out about the loss of factors guard

with deep water in the trap again. There are self siphonage, induce siphonage, back

pressure, capillary attraction, wavering out, evaporation, momentum and leakage. In

addition, I can find out how to overcome them.