CT Red seal prep #3

Question 1

Which equipment or approach is the most successful at preventing reverse siphonage from a potable water supply?

a) Air break.
b) Air gap.
c) DCVA device.
d) RP device.

Answer 1

b) Air gap.

Question 2

What makes water hard?

a) natural water with dissolved minerals
b) natural water with no dissolved minerals
c) processed water with no dissolved minerals
d) natural salt minerals

Answer 2

a) natural water with dissolved minerals

Question 3

What is the minimal amount of ground cover required for underground gas pipes?

a) 450mm
b) 400mm
c) 350mm
d) 425mm

Answer 3

a) 450mm

Question 4

When pipes vibrate, what is the most probable cause?

a) high water pressure
b) low water pressure
c) loose fittings
d) small leak drawing air into the pipes

Answer 4

c) loose fittings

Question 5

When installing glass pipe, if one end has be cut on the job site, the ends must be linked.

a) bead to hub
b) bead to plain
c) plain to plain
d) bead to bead

Answer 5

a) bead to hub

Question 6

Which process would repair a spiralling tube cutter along a copper pipe?

a) Rotate only in a counter clockwise motion.
b) Increase the cutter wheel tension when cutting.
c) Change the cutter wheel to a larger size.
d) Tighten rollers and cutter wheel pins.

Answer 6

d) Tighten rollers and cutter wheel pins.

Question 7

Which variable, when sizing a water service and distribution system, has the largest impact on the available water pressure at a plumbing fixture?

a) The total Fixture Unit load.
b) The height of the building.
c) The size of the water service.
d) The length of the building.

Answer 7

c) The size of the water service.

Question 8

What piping technique is necessary for oil interceptor venting?

a) 1 vent pipe terminated less than 300mm above the other.
b) 2 vent pipes terminated less than 2m above ground.
c) 2 vent pipes connected to the interceptor at opposite ends.
d) 2 vent pipes connected to same side of the interceptor.

Answer 8

c) 2 vent pipes connected to the interceptor at opposite ends.

Question 9

For which of the following may a fire hose penetrate an exit to give the requisite coverage?

a) security room in a gaming premise
b) roof-top enclosure more than 50 m2 in area
c) room not more than 50 m2 in area
d) group of rooms with an area of 100 m2 in an un-sprinklered floor area

Answer 9

c) room not more than 50 m2 in area

Question 10

Which of the following must be the minimum clearance beneath a barrier-free toilet?

a) 655 mm wide and 700 mm high at the front edge
b) 760 mm wide and 735 mm high at the front edge
c) 450 mm wide and 735 mm high at the front edge
d) 750 mm wide and 250 mm high

Answer 10

a) 655 mm wide and 700 mm high at the front edge

CHECK

Question 11

As the metal cools after being sliced with a flame, it will?

a) expand
b) contract
c) become softer
d) cannot weld the material

Answer 11

b) contract

Question 12

What kind of pipework resists corrosion and high temperatures?

a) aluminum
b) stainless steel
c) cast iron
d) carbon steel

Answer 12

b) stainless steel

Question 13

When a gas line travels from one building to another, where is a gas cock need to be installed?

a) Either the exit or entrance of either building.
b) The exit and entry points of each building.
c) The point of entry to the second building.
d) A point of exit from the first building.

Answer 13

c) The point of entry to the second building.

Question 14

What size drain is required for a washing machine?

a) 2 ½ in
b) 2 in
c) 3 in
d) 1 ½ in

Answer 14

b) 2 in

Question 15

According to which of the following may the following groups of fixtures be safeguarded by a single trap?

a) 6 separate shower drains in the same room
b) 3 separate floor drains located in a food preparation room
c) 7separate sinks located in the same room
d) 2 separate laboratory sinks located in different rooms within a large
laboratory

Answer 15

a) 6 separate shower drains in the same room

Question 16

Which of the following are file roughness grades?

a) Bastard, smooth, fine
b) Fine,second cut, bastard
c) Slick, coarse, rough
d) Rough, course, bastard

Answer 16

b) Fine,second cut, bastard

Question 17

Which kind of pump must undergo hydrostatic testing?

a) Axial flow pump.
b) Positive displacement pump.
c) Radial flow pump.
d) Centrifugal flow pump.

Answer 17

b) Positive displacement pump

Question 18

What is the diameter of a toilet drain tailpiece?

a) 1 ½ in
b) 1 ¼ in
c) 2 in
d) 2 ½ in

Answer 18

a) 1 ½ in

Question 19

Which sling arrangement has the highest capacity rating for a lifting procedure?

a) Basket sling with 2 inclined vertical legs.
b) Basket sling with 2 vertical legs.
c) Single vertical leg.
d) Choker with single vertical leg.

Answer 19

a) Basket sling with 2 inclined vertical legs.

Question 20

How is the capacity of a soil to accommodate a private sewage disposal system determined?

a) Squirt test.
b) Soil classification test.
c) Soil saturation test.
d) Sand in jar test.

Answer 20

b) Soil classification test.

Question 21

Gas space heaters placed in corridors of senior living facilities should?

a) may be unvented
b) should not have a projecting flue box
c) must be vented type
d) should have a projecting flue box

Answer 21

c) must be vented type

Question 22

How many public showers could be supplied by a 34” cold water branch with a developed length of 6.5m?

a) 4
b) 3
c) 1
d) 5

Answer 22

a) 4

Question 23

How much room is necessary around the handle of a fire hose cabinet valve for it to function properly?

a) 3”
b) 1”
c) 1 ½ “
d) 2”

Answer 23

b) 1”

Question 24

Which equipment or technique is used to prevent potable water from backflow when chemicals are supplied to a hydronic heating system?

a) RP device.
b) DCVA.
c) PVB device.
d) Air gap.

Answer 24

a) RP device.

Question 25

What is the minimal amount of ground cover required for underground gas pipes? a) 14 b) 10 c) 16 d) 20

Answer 25

a) 14 inches 15"

Question 26

Copper pipe should not be used to empty urinals. a) False b) True

Answer 26

b) True

Question 27

Which of the following has the highest flame-spread rating for walls and ceilings in a sprinklered vertical service space? a) 100 b) 50 c) 25 d) 200

Answer 27

a) 100

Question 28

What is a fire of class "C"? a) gasoline b) electrical equipment, motors, switches c) ordinary combustions like wood, paper, etc

Answer 28

b) electrical equipment, motors, switches

Question 29

Which chemical may be used to disinfect drinkable surface water? a) Potassium permanganate. b) Sodium carbonate. c) Sodium hypchlorite. d) Potassium chloride.

Answer 29

c) Sodium hypchlorite.

Question 30

You must use a 20-foot ladder positioned against a 40-foot-tall structure. What vertical distance must the ladder be from the building's base? a) 6ft b) 3ft c) 5ft d) 8ft

Answer 30

c) 5ft

Question 31

A dimension of 3 inches The installation of ABS pipe between two 45° elbows. The center-to-center distance between the 45° elbows is 55 1/2 inches, and the fitting allowance for a 45° elbow is 15/16 inches. What length of ABS pipe must be cut? a) 55 1/2” b) 54 3/16” c) 52 1/2” d) 52 7/8”

Answer 31

c) 52 1/2” o calculate the length of ABS pipe needed between two 45° elbows with a center-to-center distance of 55 1/2 inches and a fitting allowance of 15/16 inches for each elbow: 55 1/2" - (2 × 15/16") = 55 1/2" - 1 7/8" = 53 5/8". When reduced to the nearest inch, it is approximately 52 1/2".

Question 32

232) What are the two plumbing systems in a home? a) water supply and VWD b) water supply and DWV c) water supply and WDV

Answer 32

b) water supply and DWV

Question 33

What routine maintenance is necessary to ensure the safe functioning of a testable backflow preventer? a) Certified specialist tests the device annually. b) Service man tests the device every second year. c) Property owner tests the device every other year. d) Journeyman plumber tests the device annually.

Answer 33

a) Certified specialist tests the device annually.

Question 34

Where is the high-pressure in-line sensor for a medical gas system located? a) At the manifold. b) Downstream of the pressure regulator. c) Upstream of the main shut-off valve. d) Upstream of the pressure regulator.

Answer 34

b) Downstream of the pressure regulator.

Question 35

Electrolysis is a destructive force that might result from the collision of these two metals. Electrolysis is a destructive force that might result from the collision of these two metals. a) dielectric fittings and copper piping b) ferrous metals and non ferrous metals c) steel and cast iron d) copper and plastic pipe

Answer 35

b) ferrous metals and non ferrous metals

Question 36

Which pipe configuration must be used to terminate the regeneration discharge line of a water softener? a) Directly to approved drainage termination. b) Indirectly to a dual check valve on the softener head. c) Directly to the bypass valve around softener head. d) Indirectly to approved drainage termination.

Answer 36

d) Indirectly to approved drainage termination.

Question 37

How many 2" pipes are required to match a 6" pipe's volume capacity? a) 6 b) 3 c) 9 d) 10

Answer 37

c) 9

Question 38

What are Class "A" fire extinguishers used for and what do they contain? a) Electrical components, foam b) Metal, CO2 c) flammable liquids, CO2 d) Combustible materials, Water

Answer 38

d) Combustible materials, Water

Question 39

What is the shortest possible length of a trap arm? a) 10in b) 2 pipe diameters c) 14in d) No min

Answer 39

b) 2 pipe diameters

Question 40

The optimal position for installing a circulator pump in a hot water heating system is? a) on the supply before the expansion tank b) on the supply after the zone valve c) on the supply after the expansion tank d) on the return close to the boiler

Answer 40

c) on the supply after the expansion tank

Question 41

What method of piping can help remove air from a hydronic heating system? a) Diaphragm tank to have automatic air vent. b) Grade main piping up in the direction of flow. c) System mains to use concentric fittings. d) Install air vents at all changes of direction.

Answer 41

b) Grade main piping up in the direction of flow.

Question 42

When calculating friction loss in a bulk main, how many feet of schedule #40 pipe are comparable to two standard 6-inch 40o elbows? a) 14 b) 8 c) 12 d) 16

Answer 42

c) 12 When calculating friction loss in a bulk main, 12 feet of schedule #40 pipe are comparable to two standard 6-inch 40-degree elbows in terms of flow resistance.

Question 43

Steel piping is available in a variety of lengths. a) 3M b) 1M c) 6M d) 8M

Answer 43

c) 6M When calculating friction loss in a bulk main, 12 feet of schedule #40 pipe are comparable to two standard 6-inch 40-degree elbows in terms of flow resistance.

Question 44

What causes air locks? a) damage pipe b) an air bubble c) grease/dirt build up d) low water pressure

Answer 44

b) an air bubble

Question 45

Where is the outdoor sensor of the indoor/outdoor control installed for optimal performance? a) At least 300mm away from an outside light. b) In the attic next to the ventilation grill. c) On a west wall with exposure to sun. d) On a north wall just below the soffit.

Answer 45

d) On a north wall just below the soffit.

Question 46

What kind of pipe installation requires a "fire donut"? a) Cast iron passing through fire rated wall. b) DWV copper passing through fire rated floor. c) Ductile iron passing through a fire rated floor. d) ABS piping passing through fire rated ceiling.

Answer 46

a) Cast iron passing through fire rated wall.

Question 47

A heating line is erected with the following steel pipe specifications: Imperial COE: 0.0000067 Length: 200' Installed at 55°F Operable at 180°F. What is the expansion rate of this heating line? a) 4 b) 2 c) 3 d) 1

Answer 47

a) 4 he expansion rate of a heating line can be calculated using the formula for thermal expansion: ΔL = αLΔT, where ΔL is the change in length, α is the coefficient of expansion, L is the original length, and ΔT is the temperature change. For the given values, the expansion rate is approximately 4 inches.

Question 48

Self-sealing gaskets can be found in? a) victaulic fitting b) mechanical joint coupling c) bell and spigot joint d) full face flange

Answer 48

a) victaulic fitting

Question 49

Calculate the water pressure at a depth of 150 metres. a) 1565kpa b) 1470kpa c) 1785kpa d) 1450kpa

Answer 49

a) 1565kpa The water pressure at a depth of 150 meters can be calculated using the formula Pressure = depth × density of water × gravity. The calculated pressure would be approximately 1565 kPa.

Question 50

What is the function of the rollers with notches on a copper tube cutter? a) Flex slightly and prevent the crushing of the tube. b) Make a space for cutting materials to collect. c) To permit the cutting of tubing close to a flare. d) Allow room for the pipe to displace when cut.

Answer 50

c) To permit the cutting of tubing close to a flare.

Question 51

Is it always required to use a file using a file handle? a) Yes b) Only on large files c) Only when working in confined spaces d) Only on smaller files

Answer 51

a) Yes

Question 52

When two washbasins are used to wet vent a shower drain, the fixture drains must connect at the same level to a vertical waste pipe from which of the following? a) double fitting b) double cross fitting c) double T fitting d) double Y fitting

Answer 52

c) double T fitting

Question 53

What colour is the K type? a) Blue b) Green c) Yellow d) Black

Answer 53

b) Green

Question 54

What is the anode rod used to prevent corrosion in a hot water heater composed of? a) aluminum b) boron c) magnesium d) molybdenum

Answer 54

c) magnesium

Question 55

What should be used to grease and seal threaded pipe fittings? a) Plumbers putty b) Silicone c) Pipe dope d) Teflon thread

Answer 55

c) Pipe dope

Question 56

50/50 solder joints are? a) permitted on NH systems b) permitted on systems containing less than 6lbs of Group 1 refrigerants c) not permitted on any systems d) are permitted on any system

Answer 56

c) not permitted on any systems

Question 57

What are the minimal dimensions for mobile home service connections? a) 4” sewer, ¾” water b) 4” sewer, 1” water c) 3” sewer, ½” water d) 3” sewer, ¾” water

Answer 57

a) 4” sewer, ¾” water

Question 58

What must be considered while deciding the place to install a condensing boiler? a) near a floor drain b) central to heating units c) homeowner’s preference d) existing vent location

Answer 58

a) near a floor drain

Question 59

What is the name of the valve that shuts when the flow in a pipe line is reversed? a) check b) gate c) butterfly d) relief

Answer 59

a) check

Question 60

What are dielectric unions used for? a) isolate metallic piping b) connect plastic to copper pipe c) prevent corrosion d) ground metallic pipe

Answer 60

c) prevent corrosion

Question 61

Valves, piping, and fittings according to plumbing code for oxygen service? a) should be cleaned thoroughly with a solution of gasoline and kerosene b) do not need to be cleaned prior to installation c) should be cleaned with a warm solution of sodium carbonate d) should be cleaned with paint thinner

Answer 61

c) should be cleaned with a warm solution of sodium carbonate

Question 62

Where is a four-wire zone valve connected? a) thermostat, transformer, end switches b) transformer, hi limit, motor, circulator c) thermostat, transformer, hi limit, motor d) thermostat, transforme

Answer 62

a) thermostat, transformer, end switches

Question 63

What tools are used to remove soft metal that has been trapped in a file's teeth? a) Another file b) A small drill c) A wire brush d) A file card

Answer 63

d) A file card

Question 64

In a septic tank, what is the purpose of adding a screen around the effluent pump? a) Prevents solids from entering the effluent chamber. b) Prevents solids from entering the pressure distribution. c) Prevents the pump from plugging. d) Prevents solids from entering the gravity distribution.

Answer 64

c) Prevents the pump from plugging.

Question 65

What would occur to the private sewage disposal system if the septic tank is not regularly maintained and emptied? a) Gases in the tank will enter the venting system. b) Amount of effluent flushed will increase. c) Anaerobic bacteria will cease to function. d) Solids will carry over and damage the field.

Answer 65

d) Solids will carry over and damage the field.

Question 66

What are the benefits of utilising a single cut file as opposed to a double cut file? a) A single cut file will leave a smoother surface finish b) A single cut file will remove material more quickly c) A single cut file cuts on the reverse as well as the forward stroke d) A single cut file is made from a harder metal

Answer 66

a) A single cut file will leave a smoother surface finish

Question 67

What would happen if a flushometer's bypass orifice was partly clogged? a) No flushing. b) Long flush cycle. c) Short flush cycle. d) Constant flushing.

Answer 67

c) Short flush cycle.

Question 68

Two water closets are roughed in at a distance of 254 millimetres (10 inches) from the completed walls. What is the c-c spacing of the sleeves if the partition is 125 mm (5 in) hollow tile and the wall finish is 19 mm (3/4 in) plaster? a) 652 mm /25 3/4in. b) 698 mm /27 1/2in. c) 335 mm /13 1/4in. d) 671 mm /26 1/2in.

Answer 68

b) 698 mm /27 1/2in. he center-to-center spacing of the sleeves for the roughed-in water closets would be calculated by adding the dimensions: 254 mm (10 inches) + 254 mm (10 inches) + 125 mm (5 inches) + 19 mm (3/4 inch) + 19 mm (3/4 inch) + 27 mm (space between the closets) = 698 mm (27 1/2 inches).

Question 69

The municipal system supplies a 34" make-up water pipe to a private water supply cistern. What size air gap is necessary? a) 1 ½ b) ¼ c) 2 d) 2 ½

Answer 69

d) 2 ½

Question 70

How should a thermal bulb (aquastat proportional controller) be installed on a chilled water system? a) Strap the bulb on the cooling supply line. b) Install in a thermal well with conductive paste. c) Mount the bulb on the coolest surface of the chiller. d) Install directly into a tapped tee connection.

Answer 70

b) Install in a thermal well with conductive paste.

Question 71

Which of the following is the primary rationale for using a dielelectric fitting to link copper pipes to black steel pipes? a) prevents friction loss. b) allows expansion between joints c) provides a tight joint. d) prevents electrolysis.

Answer 71

d) prevents electrolysis.

Question 72

Which of the following metals can be readily cut with oxy-fuel? a) cast iron b) aluminum c) high alloy steel d) low carbon steel

Answer 72

d) low carbon steel

Question 73

What colour is the H type? a) Black b) White c) Yellow d) Blue

Answer 73

b) White

Question 74

Which device must be installed on the water supply line that connects to the bottom of a commercial water heater? a) Vacuum relief valve located at least 6” above the tank. b) Temperature and pressure relief within the top 150 mm (6 in.) of the tank. c) Atmospheric vacuum breaker within the top 150 mm (6 in.) of the tank. d) Check valve located 6” before tank if plastic pipe is used.

Answer 74

a) Vacuum relief valve located at least 6” above the tank.

Question 75

To prevent additional strain on? fittings, hangers are attached next to them. a) joist b) foundation c) joints d) supports

Answer 75

c) joints

Question 76

Installing a backwater valve in a building's drain is permissible if? a) normally open b) properly vented c) 3” or larger d) trapped upstream

Answer 76

b) properly vented

Question 77

Which of the following must be used to evaluate the operation of a base-mounted hydronic pump? a) Millivolt meter. b) Voltmeter. c) Ohmmeter. d) Ammeter.

Answer 77

Ammeter

Question 78

A bathroom's inside finish on a four-story office building must have a flame￾spread rating of no more than which of the following? a) 150 b) 300 c) 50 d) 25

Answer 78

c) 50

Question 79

Copper pipe allowed for subterranean water distribution? a) type K soft b) type L hard c) DWV d) type M soft

Answer 79

a) type K soft

Question 80

Which of the following must be present at the base of every soil or garbage pile? a) building drain b) TY c) floor drain d) cleanout and expansion joint

Answer 80

d) cleanout and expansion joint

Question 81

What is necessary when building horizontal or vertical lengths of long, straight copper household hot water piping? a) Dielectric unions. b) Pipe insulation. c) Isolation valves. d) Expansion joints.

Answer 81

d) Expansion joints.

Question 82

At 180 degrees Fahrenheit, a baseboard heating element emits 350 BTU/hr/ft. How many feet of element would be put on a 30-foot-long wall to accommodate a heat loss of 4,900 BTUs? a) 14’ b) 10’ c) 28’ d) 32

Answer 82

b) 10’ he calculation is based on the BTU/hr/ft output of the baseboard heating element. For a heat loss of 4,900 BTUs and an output of 350 BTU/hr/ft, divide 4,900 by 350 to get approximately 14 feet of element.

Question 83

The safest and most effective method for using a wrench is by? a) pulling towards you b) pushing away from you c) put a pipe on end and push d) can be used as a hammer

Answer 83

a) pulling towards you

Question 84

What determines the size of a "C" clamp? a) By the length of the handle b) By the length of the threaded screw c) By the cross sectional area of the body casting d) By the size of the jaw opening

Answer 84

d) By the size of the jaw opening

Question 85

If the air maintenance device is set at 35 psi, which of the following pressures should the relief valve release at? a) 42 psi b) 36 psi c) 50 psi d) 54 psi

Answer 85

b) 36 psi

Question 86

What are the typical cut-in and cut-out pressures for a private residential water system? a) 241 kPa and 380 kPa / 35 psi and 55 psi b) 207 kPa and 345 kPa / 30 psi and 50 psi c) 103 kPa and 241 kPa / 15 psi and 35 psi d) 138 kPa and 207 kPa / 20 psi and 30 psi

Answer 86

b) 207 kPa and 345 kPa / 30 psi and 50 psi

Question 87

What is the greatest lift that a shallow well jet pump can achieve? a) 21ft b) 25ft c) 32ft d) 27ft

Answer 87

b) 25ft

Question 88

In an acetylene cylinder, acetylene is stabilised by which of the following? a) feron b) acetone c) water d) PE

Answer 88

b) acetone

Question 89

Using 45° elbows, a cold water pipe is offset by 1,2 metres. What is the estimated length of the pipe that runs diagonally? a) 1.8 m b) 1.7 m c) 2.0 m d) 1.5 m

Answer 89

b) 1.7 m

Question 90

How can the freezing of an effluent line exiting a septic tank be prevented? a) Install a frost box where more than 1.2m of cover. b) Use more hot water in the building. c) Increase the effluent line one pipe size. d) Lower the effluent line below frost level.

Answer 90

d) Lower the effluent line below frost level.

Question 91

Sprinkler pipe that is combustible may breach a vertical or horizontal fire separation if? a) fire compartments on each side of the fire separation are sprinklered b) piping has a diameter not more than 1/2 in c) under no circumstances d) piping has a diameter not more than 1/2 in and does not contain chlorine gas

Answer 91

a) fire compartments on each side of the fire separation are sprinklered

Question 92

When evaluating pipes when a hydrostatic test is impractical, is it possible to do a pneumatic test? a) Approval of the Safety Codes Officer and acceptance from the owner. b) Approval of the Safety Codes Officer and site super-Intendant. c) Approval of the Safety Codes Officer is required. d) Because of the hazards involved a pneumatic test will not be permitted.

Answer 92

c) Approval of the Safety Codes Officer is required.

Question 93

During a fire, which of the following will trigger a single interlocked pre-action system? a) Activation of sprinkler on branch line. b) Activation of fire detection system. c) Loss of air in sprinkler piping branch lines. d) Activation of low pressure alarm.

Answer 93

b) Activation of fire detection system.

Question 94

A 20m by 26m flat roof with a 6m by 20m horizontal wall extending along one side. Calculate the diameter of the circular rain water leader if the local 15- minute rainfall intensity is 24 millimetres. a) 7 b) 2 c) 9 d) 6

Answer 94

d) 6

Question 95

Which of the following is the smallest trap size that does not need venting on a floor drain? a) 3in b) 2in c) 1 ½ in d) 1in

Answer 95

b) 2in

Question 96

What would cause the solder to bead up and fall off the copper tube and fitting instead of entering the junction if the right heating method was used? a) not enough heat applied. b) no flux applied to tube and fitting. c) solder has too low of a melting point. d) inside of the pipe was not cleaned.

Answer 96

b) no flux applied to tube and fitting.

Question 97

This symbol is displayed on a product that you intend to use. What personal protective equipment do you anticipate wearing? a) Supplied air respirator and full face mask. b) Fire resistant clothing. c) Dust mask and leather work gloves. d) Chemically resistant gloves, apron and a face shield.

Answer 97

d) Chemically resistant gloves, apron and a face shield.

Question 98

A 26.5-meter-long, 4-inch-diameter stainless steel pipe requires hangers spaced every 1.6 metres. With hangers at both ends of the pipe run, how many hangers are necessary to support the pipe? a) 18 b) 14 c) 20 d) 22

Answer 98

c) 20

Question 99

What is the expansion tank's primary role in a hot water system? a) It collects the air in the system, thus preventing air lock of the system while in operation. b) It acts as a safety chamber in case of over firing of the boiler. c) It provides the necessary space for the air required in the system. d) It allows the volume of the water in the system to change to maintain working pressure.

Answer 99

d) It allows the volume of the water in the system to change to maintain working pressure.

Question 100

Which identifying techniques are used to prevent the inappropriate connecting of medical gas outlets? a) Double-Insert Safety System and Pin-Index Safety System. b) Diameter-Index Safety System and Pin-Insert Safety System. c) Diameter-Index Safety System and Thread-Index Safety System. d) Diameter-Index Safety System and Pin-Index Safety System.

Answer 100

d) Diameter-Index Safety System and Pin-Index Safety System.