hard ones

Question 1

(3.8) In what systems are scroll compressors usually found?

Answer 1

in new residential and light commercial air conditioning applications.

Question 2

(6.2) What is the name of a rivet and pin together?

Answer 2

a mandrel

Question 3

(6.3) How are wood crews specified?

Answer 3

by shank number (0 to 24) and length (in inches)

Question 4

(6.3) What are sheet metal screws also known as?

Answer 4

tapping screws

Question 5

(7.2) How is copper piping categorized?

Answer 5

K, L, M , DWV (K being heavy duty, DWV is used for drainage and waste).

Question 6

(7.2) How is ACR sized

Answer 6

by OD

Question 7

(7.2) Define annealing

Answer 7

the process of heating and slowly cooling a metal in order to strengthen it.

Question 8

(7.7) What is the soldering temperature range?

Answer 8

361F to 500F

Question 9

(7.7) What is the brazing temperature range?

Answer 9

1205F to 1550F

Question 10

(7.16) What are the only type of threads used on steel pipe in the industry?

Answer 10

tapered threads

Question 11

(7.18) What is ABS piping for?

Answer 11

drainage, waste, ventilation.

Question 12

(7.18) What is PE piping for?

Answer 12

cold water, gas, irrigation.

Question 13

(8.3) How do you check for cumulative microleaks?

Answer 13

use a helium mass spectrometer

Question 14

(8.3) How do you check for combination-dependent leaks?

Answer 14

pressure, then vibration, then heat.

Question 15

(8.7) How many microns are in 1 inch of mercury?

Answer 15

25,400

Question 16

(9.2) Where is good ozone located?

Answer 16

stratosphere

Question 17

(9.2) where is bad ozone located?

Answer 17

troposphere

Question 18

(9.5) Why is July 1st, 1992 an important date?

Answer 18

it became illegal to intentionally vent CFC and HCFC refrigerants.

Question 19

(9.5) When were CFCs phased out?

Answer 19

January 1st, 1996

Question 20

(9.5) What is the GWP and ODP of CFCs?

Answer 20

high both of them.

Question 21

(9.5) What are some examples of CFC refrigerants?

Answer 21

any R-10s like R-11 and R-12

Question 22

(9.6) What is the GWP and ODP of HCFC refrigerants?

Answer 22

medium GWP, medium ODP

Question 23

(9.6) When are HCFCs scheduled to be phased out?

Answer 23

by 2030

Question 24

(9.6) What did the montreal protocol accomplish?

Answer 24

signed in 1987 to control the release of ozone depleting substances.

Question 25

(9.7) Why is November 15, 1995 an important date?

Answer 25

it became illegal to intentionally vent HFC refrigerants

Question 26

(9.7) What are some examples of HFC refrigerants?

Answer 26

R-134A, R-410A