7. Joints.

Question 0

2. What shall you use to braze medical gas piping instead flux?

Answer 0

BCuP brazing alloys where phosphorus work like flux.

Question 1

1. The average length per 1 lb. roll of common 50-50 Sn- Pb solder and the alternative solders?

Answer 1

50-50: 21 to 22 feet.

The alternative: 26 - 27.feet.

Question 2

3. What is lead wool? When is it used for making calked joints?

Answer 2

Lead wool is composed of long fine strands of metallic lead wound into a loose rope. In this form, when calked it forms a solid mass of lead. Lead wool is especially useful in making joints in cast-iron pipe under water or bad moisture conditions. It is used on joints when there is insufficient room to pour the joint with melted lead. Since it does not have to be molten, it can be used where it is not advisable to use fire, for example, where inflammable gases are present

Question 3

4. How can a flux be made which sill be suitable for making silver solder joints on copper tubing?

Answer 3

A suitable flux can be made for this type of solder by mixing powdered borax and alcohol or water to a thin, milky solution.

Question 4

5. Composition and properties of common solders.
Composition by percent - chemical symbols - working range.
50;50 - 
60:40 -
40:60 - 
95:5 -
97:3 - 
85:15 - 
85:15 - 
96:4 - 
94:6 -
95:5 -

Answer 4

50;50 - Sn:Pb - 361* to 421*F.

60: 40 -Sn:Pb - 361* to 374F.
40: 60 - Sn:Pb - 361 to 460F.
95: 5 -Sn:Sb - 452 to 464F.
97: 3 - Sn:Cu - 446 to 482F.
85: 15 - Sn:Pb - 365 to 408F.
85: 15 - Sn:Sb - 550 to 610F.
96: 4 - Sn:Ag - 430 to 430F.
94: 6 -Sn:Ag - 430F to 535F.
95: 5 -Sn:Ag - 430F to 473*F.

Question 5

6. What is most common brazing flux?

Answer 5

A water soluble fluoride-based flux and its recognized as an American Welding Society standard type.

Question 6

7. Why should I use ASTM B813 fluxes?

Answer 6

Soldering fluxes manufactured to meet the requirements of ASTM B813 are specifically designed to flush from the system with us of a minimum amount of cold water.

Question 7

8. How should You specify the use of ASTM B813 Fluxes?

Answer 7

Be sure when you are on the job site that installers are using soldering fluxes that have a label indicating that they meet the requirements of ASTM B813.

Question 8

9. Specific installation of medical gas and ACR systems?

Answer 8

Require the addition of an inert gas during the brazing process.

Question 9

11. What filler metals are most commonly used in plumbing, HVAC refrigeration and fire sprinkler systems?

Answer 9

BCuP-2 for close tolerances.

Question 10

12. Fluxes best suited for brazing copper alloy tube?

Answer 10

They shall meet AWS classification FB3-A or FB3-3C.

Question 11

13. When referring to tin lead solders, what is given 1st?

Answer 11

The tin content is customarily given first, for example 40/60 refers to 40 percent tin and 60 percent lead by weight.

Question 12

14. What is usually the flux requirement per pound of solder?

Answer 12

2 ounces pre pound of solder.

Question 13

15. Difference between brazing alloy BCuP and BAg?

Answer 13

BCuP is low silver alloy 30% silver.

Question 14

16. How is seamless copper pipe joined?

Answer 14

Generally by mechanical means such as threading , but can also be welded or brazed.

Question 15

17. What is the flux requirement for soldering job?

Answer 15

Usually 2 ounces per pound of solder.