Several forms of sewer pipes have been devised, but only one or two of the most common need be noticed.

Socket Pipes

Pipes intended to convey sewage are generally made with sockets. Care should be taken that this socket is in the same piece with the pipe, not formed separately, as is sometimes the case.

Half Socket Pipes have a socket on the lower half of the circular section only, so that a broken length may at any time be taken out and replaced, or a junction inserted.

The following Table gives the dimensions and thickness of stoneware, fireclay, and other clay pipes, as laid down by Mr. Baldwin Latham: - l

Socket Pipes 30039

Fig. 44.

Stoneware.

Fireclay.

Other Clays.

All Pipes.

Internal Diameter.

Thickness.

Length in work.

Thickness.

Length in work.

Thickness.

Depth of Socket.

Inches.

Inches.

Feet.

Inches.

Feet.

Inches.

Inches.

2

...

...

...

5/16

3

3/8

2

3/8

2

3/8

11/2

4

1/2

2

4

2

1/2

l1/2

6

5/8

2

3/4

2

3/4

13/4

9

3/4

2

4/5

2

7/8

2

10

1/8

2

1

2

...

2

12

13/4

2

11/10

2

1

2

15

11/8

2

11/4

2 to 3

11/4

21/4

18

l1/4

2 to 3

11/2

2 to 3

21/2

21/2

1 Specification For Bideford Waterworks

Humber.

Mr. Baldwin Latham states that he "has found in some cases that the thickness given in the above Table for fireclay pipes is not sufficient." 1

Socket pipes may readily be obtained as small as 2 inches in diameter; also pipes of 21, 24, and 30 inches in diameter, in 21/2 or 3 feet lengths.

Bends are curved lengths of pipe which are made to varying radii, and of 2, 3, 4, 6, 9, 12, 15, and 18 inches bore. They should always be segments of circles, and should form perfect curves when jointed together.

Taper Pipes (Fig. 45) are intended to form a connection between two pipes of different diameter.

Junctions for pipes are made in several different forms. They are usually in 2 feet lengths.

Single Junctions are those to form the joint when one pipe enters the side of another. The junction may either be at right angles to the pipe, as in Fig. 46, or joined to it by a gradual bend, as in Fig. 47. The latter is the best construction.

1 Specification For Bideford Waterworks 30040

Fig. 45.

1 Specification For Bideford Waterworks 30041

Fig. 46.

1 Specification For Bideford Waterworks 30042

Fig. 47.

Double Junctions are to form the joint where two pipes meet a third, either at the sides as in Fig. 48, or at one end as in Fig. 49.

1 Specification For Bideford Waterworks 30043

Fig. 48.

1 Specification For Bideford Waterworks 30044

Fig. 49.

Mr. Baldwin Latham gives the following directions for forming bends and junctions : - "The centre from which a branch on a main is struck must be upon a line at right angles to the centre line of the main pipe, the inside of the main pipe meeting the inside of the branch at a tangent on a radius line from which it is struck; the ends of all curved pipes must be in the direction of the radius of the curves with which they are described." 2

Saddles and Chairs in earthenware are formed of such a shape as to make a secure junction between the adjacent lengths of a sewer pipe, and yet to enable the sewer to be examined at any time, and any obstruction to be removed without breaking a pipe.

1 Latham's Sanitary Engineering.

2 Specification for Bideford Waterworks.

Figs. 50, 51 show the junctions of Jenning's improved patent drain pipes.

1 Specification For Bideford Waterworks 30045

Fig. 50.

1 Specification For Bideford Waterworks 30046

Fig. 51.

The chair is shown at C in position supporting the end of a pipe; another length would be placed in the vacant half of the chair, and then the short piece S placed between the two lengths over the chair. The bottom of the short piece is flush with that of the lengths of pipe united by it.

Some of the saddles are plain, as at P, which shows one in position. Others have junctions attached, as at J.

Other saddle and chair junctions introduced by Mr. Jennings have no short piece attached to the saddle. The chair and saddle are rebated at each end, of a depth equal to the thickness of the adjacent lengths of pipes, which therefore fit into the rebates, and have their inner surfaces flush with those of the saddle and chair.

Fig. 52 shows one of these chairs. The saddle is exactly similar in form, being made, however, with or without junctions, as in Fig. 51.

The objection to pipes with half sockets, saddles, etc., is that when the sewer is more than half full they leak or overflow.

Opercular or Lidded Pipes were introduced by Messrs. Doulton.

They are similar in form to ordinary socket pipes, but are strengthened by two ribs running lengthways, shown at r r in Fig. 53, which is a section of the pipe.

1 Specification For Bideford Waterworks 30047

Fig. 52.

1 Specification For Bideford Waterworks 30048

Fig. 53.

1 Specification For Bideford Waterworks 30049

Fie. 54.

A longitudinal nick or furrow is made throughout the length of the pipe along these flanges, so that by inserting a chisel the upper portion of the pipe between r r may easily be removed.

Thus the whole length of the pipe may be opened up for inspection or for removal of obstructions.

Capped Pipes have circular or oval holes in them, with loose covers, so that they can be examined without being broken or taken up.

Syphon Traps in stoneware may be obtained of almost any shape and description, either with or without inlets for examination.

One form is shown in Fig. 55, with the inlet dotted. This description may be obtained of 2, 3, 4, 6, 9, and 12 inches bore.

1 Specification For Bideford Waterworks 30050

Fig. 55.

The position of inlet shown in Fig. 55 is the usual one, but a trap so formed is liable to choke, and it is better to have the inlet at the upper end of the pipe.