Explain the syphon.

The syphon consists primarily of a bent tube, one arm being longer than the other. The syphon is used for transferring liquids from a high point to a lower point. In order to start the syphon, the air in the long arm must first be exhausted. As soon as this vacuum is formed, atmospheric pressure forces the water up the short arm and into the long arm, through which it passes out. This action continues unless broken by other means, until the short arm no longer dips into the water.

How may the action of the syphon be destroyed?

By admitting air into the long arm of the tube, not further from the crown of the tube than the length of the short arm.

In what way is syphonage a great benefit in plumbing work?

It is the principle underlying the action of many plumbing fixtures and devices.

In what ways is syphonage a detriment to plumbing work?

In the syphonage of traps and boilers.

Name different plumbing devices depending on syphonage for their action.

The syphon water closet, the waste-preventive urinal, the syphon lavatory, the syphon tank, the automatic tank, the syphon cesspool, and the syphon system of water supply, are among the principal devices.

Show in what way syphonage is applied to the syphon jet water closet.

A separate passage runs from the flush entrance to the bottom of the closet trap. Through this passage a powerful jet is forced, whenever the closet is flushed. This jet sends a quantity of water quickly into the outlet or long arm of the trap, where it is retarded by a bend in the outlet leg. These two causes fill the long arm full of water, and as this passes out, the air is exhausted as we have seen above, atmospheric pressure sends the contents of the closet bowl over, and we have syphonage.

Explain the syphon tank.

At the base of the syphon tank valve, there is a large flap valve connected with the tank lever. When this lever is pulled, enough water quickly enters the flush pipe to fill it, the air is expelled, and the syphon is started, continuing until the end of the short arm is out of water.

Describe different ways in which fixture traps may be syphoned.

The outlet beyond the trap may have little pitch, so that the waste sets back and fills up the pipe. When this finally moves out, it forces the air put, leaving a partial vacuum behind, with the result that atmospheric pressure forces over the contents of the trap. This same result may occur when there is a slight stoppage in the waste outlet. When this gives way and the water passes out, syphonage is liable to occur. Syphonage may also occur from the wasting of other fixtures past the entrance of a fixture waste. If the amount of waste passing through the main is sufficient to partially expel the air, a partial vacuum will be formed, and syphonage will occur.

How may a boiler be syphoned?

The danger of boiler syphonage applies chiefly to the pressure boiler. We may consider the cold water supply from the street main to the boiler as the long arm to the syphon. Now, if there is a bad break in the street, the water, if not quickly shut off, is liable to run out of the supply pipe to the boiler. This leaves a partial vacuum behind, and syphonage occurs.

Explain how syphonage may be applied in procuring a water supply.

In the first place, the spring, pond, or other supply must be at a point higher than the point at which the water is to be delivered. Then, with the short arm dipping into the source, and the line of pipe to the point of delivery acting as the long arm, the syphon will act as a smaller one would. In starting it, the air in the long arm must be exhausted, and if there are rises in the ground that the pipe must follow, air cocks should be placed at the crown of each rise of the pipe, so that by their occasional use, air lock can be destroyed.

Can a liquid be syphoned from a lower to a higher point or not, and why?

It cannot, for the reason that when both arms of the syphon are full, the contents of the long arm being heavier, will not be drawn over by the weight in the smaller arm. In other words, the suction, by means of which syphonage acts, will always be down the long arm, not up.

How is syphonage prevented in plumbing work?

By ventilation, or, as it is more commonly called, by back or counter venting.

Explain the action of the intermittent syphon.

The automatic syphon tank is nothing more than an intermittent syphon, the great difference between different makes being found in the manner in which the water is retarded in the long arm of the syphon.

Explain the action of the automatic syphon tank.

In the intermittent syphon, the supply is constant, and when it has reached the proper height, the water falls over the crown\of the syphon, down into the long arm, where the water is retarded sufficiently to produce syphonage. This continues until the short arm is out of water. The supply being continuous, the tank in a given time fills, and syphonage again acts.