This is the term used to designate the work of putting together various lengths of piping and their connecting parts. This work is associated with the machine shop, where the required lengths of piping are usually cut and threaded. The connecting parts are known as fittings. They are made in certain standard forms as a branch of re-manufacturing, and are kept in quantities among the supplies of the machine-shop store-room.

Fig. 216. Example of Pipe Fitting.

Fig. 216. - Example of Pipe Fitting.

The piping, used so extensively for conveying steam, water and gas, in many requirements other than those of engineering, is described in the chapter on the re-manufacture of metals. The standardization of the sizes and threads of fittings to agree with standard sizes and threads of piping makes it possible to use together the fittings and piping of all manufacturers. However, difficulty is occasionally found in pipe-fitting work due to the fact that the slightly tapered threads on both pipe and fittings are cut too deep or too shallow.

Reference No.

Fitting-.

Size.

Style.

1

Globe valve..............................

1/2"

2

Angle valve.............................

3/4"

3

Gate valve............................

1/2"

4

Plug cock...........................

3/4"

5

Horizontal check valve.............................

3/4"

6

Vertical check valve.............................

3/4"

7

Angle check valve....................

1"

8

screw union............................

3/4"

9

Flange union...................................

1"

10

Long screw................................

1"

11

..............do..................................

3/4"

12

Tee...........................................

3/4"

Malleable, beaded.

13

.....do..............................

3/4"

Malleable, plain.

14

..............do..................................

1/2"

Malleable, beaded.

15

Bull-head tee..................................

3/4"x1"

Do.

16

Reducing tee................................

3/4"x1"x1"

Do.

17

Four-way tee.............................

3/4"

Malleable, plain.

18

Cross...................................

3/4"

Malleable, beaded.

19

Y-branch..................................

3/4"

Cast iron.

20

Elbow.............................................

1"

Malleable, plain.

21

.....do.......................................

3/4"

Do.

22

Reducing elbow...............................

3/4"x1"

Cast iron.

23

Side-outlet elbow..............................

1"

Malleable, plain.

24

Street elbow...................................

3/4"

Malleable, beaded.

25

45o Return bend.........................

3/4"

Do.

26

Return bend...............................

1"

Cast iron.

27

Sleeve coupling........................

3/4"

28

Reducing coupling...............................

1/2"x3/4"

Malleable, plain.

29

..............do..................................

3/4"x1"

Do.

30

Extension piece......................

1/2"

Do.

31

Bushing...............................

1/2"x3/4"

32

..............do..................................

3/4"x"

33

Expansion joint....................................

1/2"

34

Cross-over.....................................

3/4"

Malleable, beaded.

35

Shoulder nipple................................

1"

36

Long nipple........................

1"

37

Cap..................................

1/2"

38

..............do..................................

3/4"

39

.....do.......................................

1/2"

40

Plug........................................

3/4"

41

..............do..................................

3/4"

42

.....do........................................

3/4"

Pipe threads are usually right handed, though left-hand threads are used for special purposes. The pipe ends are always threaded on the outside and most of the fittings are threaded to screw on the pipe end, although some fittings are made with outside threads to be screwed into other fittings. In connecting pipe and fittings, the threads are swabbed with a mixture of oil and graphite to make a tight joint which may be taken apart any time afterward.