The following is a brief synopsis of the results of tests of several well known non-siphon traps. The tests were conducted in Trenton, N. J., October 9, 1903, under the auspices of the board of health. The testing apparatus consisted of a rectangular tank of about 180 gallons capacity, located on the top floor of a house and about 40 feet from the ground. From the bottom of the tank a 1 1/2-inch iron pipe extended a distance of 35 feet to an open sink. Four feet from the bottom of the tank a tee was screwed onto- the pipe to provide a branch outlet for the traps that were to be tested. A Lunkenheimer quick-opening valve controlled the supply of water, permitting the full volume of the pipes to be turned on when required. The trap to be tested was screwed to the branch pipe, as shown in the illustration,

Table LXV - Continued Capacity American To Metric

■

Fluid Drams to Milliliters or

Cubic Centimeters

Fluid Ounces to

Milliliters

Quarts to Liters

Gallons to Liters

1 equals . .

3.70

29.57

0.94686

3.78544

2 equal . .

7.89

59.15

1.89272

7.57088

3 equal . .

11.09

88.72

2.83908

11.35682

4 equal . .

14.79

118.30

8.78544

15.14176

5 equal . .

18.48

147.87

4.73180

18.92720

6 equal . .

22.18

177.44

5.67816

22.71264

7 equal . .

25.88

207.02

6.62452

. 26.49808

8 equal . .

29.57

236.59

7.57088

30.28352

9 equal . .

33.28

266.16

8.51724

34.06896

METRIC TO AMERICAN

Milliliters or Cubic

Centiliters to

Fluid Drams

Centiliters to

Fluid

Ounces

Liters to Quarts

Decaliters to

Gallons

Hectoliters to

Bushels

1 equals . .

0.27

0.338

1.0567

2.6417

2.a375

2 equal . .

0.54

0.676

2.1134

5.2834

5.6750

3 equal . .

0.81

1.014

3.1700

7.9251

8.5125

4 equal . .

1.08

1.852

4.2267

10.5668

11.3500

5 equal . .

1.35

1.691

5.2834

13.2085

14.1875

6 equal . .

1.62

2.029

6.3401

15.8502

17.0250

7 equal . .

1.89

2.368

7.3968

18.4919

19.8625

8 equal . .

2.16

2.706

8.4534

21.1336

22.7000

9 equal . '.

2.43

3.043

9.5101

23.7753

25.5375

Table LXV Continued Capacity American To Metric 187

Fig. 166

Fig. 166. The tests to which these traps were subjected were unusually severe and cannot be taken as representative of the siphonic action they would be required to withstand in a well-designed drainage system. So severe was the siphonic action during the test that when a sheet of common note paper was placed over the elbow of the branch to which the traps were to be connected and the water turned on, a round disk was cut out of the paper as cleanly as though done with a knife.

It is a well understood principle of engineering practice that a suitable factor of safety should be provided in all structural materials and apparatus. This factor of safety seldom exceeds five times the strain to which the apparatus will be subjected. In the case of the trap tests conducted by the Trenton Board of Health, however, the siphonic action must have been at least twenty times as severe as it would have been had a vent been provided as shown by dotted lines at a. Such a vent would have made the testing apparatus conform more nearly to the conditions that obtain in a well designed drainage system. It is doubtful if in any rightly proportioned drainage system a prism of water the full bore of the pipe would flow uninterruptedly for 25 seconds at one time, consequently any of the traps that withstood the Trenton test would be perfectly safe for any plumbing installation.

Test Of The Sure Seal Trap

This trap had a seal of 4 3/8 inches and the water it contained weighed 21 1/2 ounces. The trap was subjected to a test for 5 seconds, after which it was examined and found to contain 11 1/4 ounces of water and possess a seal of 1 7/8 inches, which is the average seal in siphon traps. The test was then applied for 25 seconds, after which the seal was found to be 1 3/4 inches, or only 1/8 less than in the 5-second test.