(a) Work gloves may be cloth, leather palm, or all leather; (b) Welding gloves are gauntlet-type gloves with high

Transcription

1 Figure 16-1 cuffs (a) Work gloves may be cloth, leather palm, or all leather; (b) Welding gloves are gauntlet-type gloves with high

2 Figure 16-2 Welding boots should have smooth toes to prevent sparks from being trapped.

3 Figure 16-3 (a) The MC acetylene tank holds 10 ft 3 ; (b) The B acetylene tank holds 40 ft 3

4 Figure 16-4 Diagram of a cutaway section of a B acetylene tank showing the porous absorbent section

5 Figure 16-5 Acetylene regulator with gauges

6 Figure 16-6 (a) 22 ft 3 oxygen cylinder; (b) 55 ft 3 oxygen cylinder

7 Figure 16-7 Support the cylinder with one hand when turning on the acetylene or oxygen valves

8 Figure 16-8 Nonadjustable acetylene wrench

9 Figure 16-9 (a) Correct position for striker, off to the side of the torch tip; (b) Improper position for striker, directly in front of the torch tip

10 Figure (a) Correct appearance of oxyacetylene flame for brazing; (b) Flame with too much acetylene brings heat too close to tip, and can damage it

11 Figure (a) When first lit, low pressure acetylene has smoke; (b) Increase acetylene pressure until smoke disappears; (c) Turn on oxygen and slowly increase flow; (d) Increase oxygen until the outer feather forms into a very smooth uniform cone; (e) Excessive oxygen causes the flame to become purple and the inner cone becomes very small

12 Figure Turn off the acetylene gas valve first; for clarity, this procedure is shown with bare hands, but welding gloves should always be used

13 Figure Tip cleaning set

14 Figure File the tip flat if it has been damaged

15 Figure Use the round tip cleaner to ream the tip orifice

16 Figure Air acetylene torch kit

17 Figure Portable oxyacetylene welding and cutting rig (Courtesy Victor Equipment Company)

18 Figure Copper oxide formed by excessively heating copper pipes and fittings

19 Figure (a) Use aluminum oxide sand cloth to clean copper before brazing and soldering; (b) Be sure to clean all the way around the fitting

20 Figure Round tubing brushes can be used to clean the inside of pipe and fittings

21 Figure (a) Copper pipe before cleaning; (b) Copper pipe after cleaning; (c) Clean at least 1/2 in beyond the fitting

22 Figure (a) Insert the copper pipe into the fitting; (b) Twisting the copper pipe against the stop helps seat the fitting

23 Figure (a) Begin heating the pipe near the fitting; (b) Once the pipe is hot, move the flame onto the fitting and continue heating

24 Figure Once brazing temperatures have been reached, use a slight downward pressure on the filler rod at the braze joint and follow the joint around the fitting

25 Figure Add the filler metal straight into the joint gap

26 Figure Add a small amount of braze to the joint so that there is a smooth uniform fillet to ensure a good joint seal

27 Figure This horizontal refrigerant line is 1 in above the ground, making access to the bottom of the joint difficult

28 Figure Use the flame to heat and bend the brazing rod approximately 2 in from the end to make reaching the bottom of the horizontal joint easier

29 Figure When the fitting is completely heated, filler metal can be added from the bottom first; then follow the joint around with the tip of the filler metal ending at the top of the joint

30 Figure Inward pressure of the filler metal helps in filling the joint gap completely with brazes in the vertical up position

31 Figure The first step in braze joint testing is to cut the fitting just beyond where the pipe is seated

32 Figure Use a hacksaw to make two cuts through the entire length of the fitting

33 Figure (a) Use a pair of pliers to bend each quarter section out; (b) Flatten each section using a ball peen hammer and anvil

34 Figure (a) A thin layer of brazed metal can be seen between the pipe and fitting; (b) Area not filled with brazed metal will allow the pipe and fitting to slip, slightly revealing a very small shelf between the pipe and fitting; this area was not properly filled with brazing metal

35 Figure Electric resistance soldering gun

36 Figure Cleaning soldering gun tip

37 Figure Fluxing soldering gun tip in preparation for tinning

38 Figure Tinning soldering gun tip

39 Figure Loop wire through terminal lug to make a mechanical connection

40 Figure Hold the soldering gun against one side of the wire and lug as the solder is introduced to the opposite side

41 Figure Clip the ends of the wire as necessary to complete the job; when connecting multiple wires, have the insulation always on the inside so there is less chance of an electrical short

42 Figure Air Mapp and air propane flames wrap around the pipe for more uniform heating than oxyacetylene

43 Figure A variety of sanding cloths are available

44 Figure Apply the flux up to approximately 1/8 in from the end of the copper pipe

45 Figure Preheat the pipe before moving the flame over the fitting

46 Figure Add a small amount of additional solder to create a fillet around the joint

47 Figure Add a small amount of additional solder to create a fillet around the joint

48 Figure (a) Begin the hacksaw cut flat across the fitting; (b) Rock the hacksaw as the cut is made

49 Figure The finished cut should completely cut through only the outer fitting. A small cut into a portion of the inner fitting is OK

50 Figure Place a flat head screwdriver in the hacksaw kerf and twist to begin opening up the joint; use pliers to finish the job

51 Figure An acceptable solder joint is one that will have a minimum of small bubbles and flux inclusions

52 Figure Excessive bubbles formed by overheating and boiling solder

53 Figure From the outside, this joint looks very good; solder flowed completely across the outside face of the joint indicating that the fitting was at the proper soldering temperature

54 Figure The inside of the joint from Figure 16-53; solder did not flow through the joint because the pipe had not reached the soldering temperature due to improper heating techniques

55 Figure Resistance spot welding

56 Figure Resistance spot welding, tip cleanup

57 Figure Pedestal spot welder

58 Figure Portable spot welder