PLUMBING

Question 1

A 60 US gallon water heater weighs 52.5lbs when its empty. How much does it weigh when its full?

Answer 1

552.3lbs

60usgal x 8.33lbs/usgal = 499.8lbs

499.8lbs + 52.5lbs= 552.3lbs

Question 2

What is installed either as part of a grease interceptor or immediatly at the inlet connection point to make it more efficient?

Answer 2

Flow control device

Question 3

What would be the result of a partially plugged bypass orifice in a flushometer?

Answer 3

Long flush cycle

Question 4

The inner dimmension of a grease interceptor measures 9’ long, 4’6” wide and 5’ deep with a required 20% free board. What is the liquid capacity in the interceptor in Imp gallons?

Answer 4

9’ x 4.5’ x 5’ = 202.5cubic feet

202.5cubicft x 0.8(20%) =162cubicft

162cubicft x 62.4lb/cubicft =10108.8lb

10108.8lb / 10impgal/lb = 1010.88impgal

Question 5

When cutting borosilicate glass tube what lubricant should be used?

Answer 5

Water

Question 6

What length of cast iron soil pipe should be removed when installing an MJ wye?

Answer 6

1/4” to 1/2” longer than the wye

Question 7

What method, in addition to concrete thrust blocks, can be used to further restrain spigot PVC water service joints from seperating?

Answer 7

Serrated harnesses with lugs

Question 8

What is the required flow rate for a system that has a total heat loss of 175000 BTU and a DELTA T of 15°F?

Answer 8

(175000 BTU/hr) / (8.33lb/usgal x 15°F x 1 BTU/lb/°F)

After units cancel
175000 (hr) / (8.33 (usgal) x 15)
175000 (hr) / 124.95 (usgal)

= 1400.56 USgal/hr

(1400.56USgal/hr) / (60min/hr)

= 23.3 GPM

Question 9

What effect would a larger DELTA T have on an appliance?

Answer 9

BTU output would increase

• increase water temp
• decrease air temp

Question 10

A hydronic heating system requires an in-line flow switch. Where would this type of switch be located?

Answer 10

Supply main

Question 11

What is required when installing long, straight horizontal or vertical runs of copper domestic hot water piping?

Answer 11

Expansion joint

Question 12

What is the ideal DELTA P for compressed air systems?

Answer 12

15 psi

Question 13

Intercoolers are installed with which style of compressor?

Answer 13

On two stage compressors

Question 14

Air intakes for compressor systems should be located where?

Answer 14

In the coolest place possible

Question 15

The inspector can ask for a minimum of ___ fittings in a medical gas to be removed and inspected to see if there is oxidation present?

Answer 15

3

Question 16

Where is the in-line high pressure sensor for a medical gas system located?

Answer 16

Downstream of the pressure regulator

Question 17

Freeze packs are designed to work on ______ water

Answer 17

Standing

Question 18

What is the minimun size of copper tube permitted for medical gas distribution systems?

Answer 18

1/2”

Question 19

If performing hot work on a frozen line what must be done?

Answer 19

Re apply freeze pack to the site every 15 minutes

Question 20

All medical gases must be tested for the purity of the gas. What concentration must those gases be at?

Answer 20

100% oxygen, nitrogen and nitrous and 21% for medical air

Question 21

If you have a medical gas system with with an anticipated operating pressure of 125 psi what pressure test would it need to maintain to pass inspection?

Answer 21

187. 5 psi for 24 hours

1. 5x operating

Question 22

Which fixtures and appliances must be installed with a shut-off valve in a public building?

Answer 22

All fixtures and appliances

Private (residential) only requires water closet, building iso and hot water tank

Question 23

What water treatment equipment is required if coliforms are detected in a water supply?

Answer 23

Chlorinator

Question 24

If there is a pressure of 50 psi at street level, how high will the pressure lift water contained in a 2” veritcal water pipe?

Answer 24

50psi x 2.31psi/foot = 115.5’

Question 25

A jet pump was seen operating properly at instllation. The installer properly set the cut in and cut out to 30-50psi. Months later the owner is seeing pressures as high as 70 psi before the pump shuts down. What is most likely the reason?

Answer 25

Obstructed or slightly kinked pressure switch tubing

Question 26

What is the minimum size water service?

Answer 26

3/4”

Question 27

Polybutylene piping should not come in contact with what?

Answer 27

Chlorine

Question 28

What is your grade % if you have 216” of drop and 500’ of run?

Answer 28

500’ x 12” = 6000” 6000” / 216” = 0.036 0.036 x 100 = 3.6%

Question 29

How many GPG does soft water have?

Answer 29

Less than 1 gpg (hardness)

Question 30

Where a 4” building trap is installed in a system what provisions must be met?

Answer 30

- it must have a cleanout upstream and downstream of the building trap - must have a 4” fresh air inlet not more than 1.2m upstream of the building trap

Question 31

What is a class K fire extinguisher used for?

Answer 31

Grease

Question 32

What device is installed on the downstream side of a high pressure steam safety valve that vents to the roof?

Answer 32

Drip pan elbow

Question 33

What is the purpose of an insulated service valve insatlled on gas pipe exiting the ground and entering the building?

Answer 33

It breaks the contact between the ground and the building piping

Question 34

How should you properly prepare a CPVC end?

Answer 34

Deburr and bevel

Question 35

Regarding DWV piping, what is the maximum plus or minus pressure allowed in a system?

Answer 35

1” WC

Question 36

A PVC DWV system is running horizontally for 136m, how many clevis hangers will need to be ordered?

Answer 36

PVC/ABS hanger spacing = 1.2m 136m / 1.2m = 113.333333 Round up add 1 =115

Question 37

What can be installed to correct periodic discharge from a reduced pressure principle backflow preventer when the water distribution pressure is expected to fluctuate?

Answer 37

Install a swing check upstream of the RP

Question 38

What would the size of the required yoke vent be in a high rise if the vent stack is 2” and the waste stack is 3”?

Answer 38

11/2” 1 size smaller than smallest connected pipe

Question 39

The base of a soil stack is 6” in diameter and the stack vent on top of it is 3” in size. The stack is required to have a nominally horizontal offset greater than 1.5m. The offset relief vent required on either side of the offset will be required to be what size?

Answer 39

2” 1 size smaller than the stack vent

Question 40

What is the minimum sized vent that must be provided for any future installations in a building?

Answer 40

11/2”

Question 41

A flat roof that measures 25m x 50m with a perpendicular wall that is 7m x 50m will require what size leader if local rainfall intensity is 20mm for 15 minutes?

Answer 41

25m x 50m = 1250m 7m x 50m = 350m - Take 50% of perpendicular wall area 350m x 0.5 = 175m 1250m + 175m = 1425m 1425 x 20(rainfall intensity) = 28500 Size off of 2.4.10.11 (6” leeder)

Question 42

What fitting would be used to attatch a field cut glass tube to a non-field cut glass tube?

Answer 42

Bead to Plain

Question 43

What decice is required on a water supply connecting to the bottom of a commercial hot water heater?

Answer 43

Vaccume relief valve installed at least 6” above the tank

Question 44

What provision must be made for a gas room heater insatalled in a hallway in a seniors home?

Answer 44

Must be vented type | Applicable in any public place

Question 45

How should a threaded joint be made between threaded galvanized steel piping and copper tubing?

Answer 45

Brass MIP

Question 46

What determines the minimum size of a suction pipe on a well pump?

Answer 46

Size of the inlet of the pump

Question 47

What is the sacrificial anode in a hot water tank manufactured from?

Answer 47

Magnesium

Question 48

Steel piping comes in what usual lengths?

Answer 48

6m 21 feet in the real world

Question 49

What color codes are type k, l and m copper?

Answer 49

K (kermit) = green L (lake) = blue M (murder) = red

Question 50

What type of thread is on acetylene fittings?

Answer 50

Left

Question 51

A 3/4” extracted tee may be formed from?

Answer 51

1” type K Tee is 1 size smaller than pipe size and always use type K

Question 52

What force would be exerted on a 9” blind flange at the base of a 30’ column filled with water?

Answer 52

Convert feet to psi 30’ x 0.433psi/foot = 12.99 psi Find surface area of flange A= 3.14(4.5)Squared A= 63.585 63.585 x 12.99 = 825.98psi

Question 53

How do you convert height into pressure? How do you convert pressure into height?

Answer 53

#feet x 0.433 #psi x 2.31

Question 54

What should the relief valve on a compressed air receiver tank be set to discharge at if the cut out pressure of the compressor is set to 45psi?

Answer 54

55 psi 10psi above cut out

Question 55

What size is the cleanout on a 6” sanitary building drainas it exits a building?

Answer 55

4”

Question 56

What backflow preventer is not testable?

Answer 56

DuC Dual check valve

Question 57

How do you determine maximum trap arm length?

Answer 57

Fall of 1 pipe diamter

Question 58

What is the maximum practical lift of a shallow well pump?

Answer 58

25’

Question 59

What provision must be made for an autopsy table that receives potentially dangerous bio-hazard waste?

Answer 59

Must be installed with a cleanout above flood level rim

Question 60

How should piping in a pneumatic system be installed?

Answer 60

Graded towards the oulets with branches rising up off the mains

Question 61

A combined building sewer has a sanitary hydraulic load of 549 fixture units and 8 rainwater leaders with 2750 litres each. What size is the sewer graded at 1%?

Answer 61

2750L x 8 = 22000L 549 FU X 9.1L/FU = 4995.9L 22000L + 4995.9L = 26995.9 Size according to 2.4.10.9 (10”)

Question 62

How many pounds are in a US gallon?

Answer 62

8.33 lb/gal Example… 60USgal x 8.33 lb/USgal = 499.8lb

Question 63

How much does 1 cubic foot of water weigh?

Answer 63

62.4 lb/cubicft

Question 64

How many litres are in an imperial gallon?

Answer 64

4.54 l/impgal

Question 65

How do you calculate linear expansion?

Answer 65

Table A-2.3.3.9. Length change = original length x coefficient of expansion x temp change

Question 66

The waste for the closed coupled tank type W.C. is roughed in at?

Answer 66

305 mm (12") from finished wall

Question 67

A blowout W.C. cannot be?

Answer 67

Horizontally wet vented

Question 68

A floor drain can be protected from back flow by a?

Answer 68

Gate valve | Screw cap

Question 69

The minimum distance permitted between two shower heads is?

Answer 69

750mm

Question 70

A relief vent is most closely related to a?

Answer 70

Vent stack

Question 71

Not more than how many showers can be served by one drain?

Answer 71

6

Question 72

A yoke vent is required when the soil or waste stack extends through a number of storeys. An additional circuit vent is also required when?

Answer 72

More than 8 fixtures are installed between vents

Question 73

The minimum air break for an indirect waste pipe that is 1 ¼" is?

Answer 73

1 1/4”

Question 74

Which does not require a vent?

Answer 74

a) Lavatory trap b) Trap forming part of an indirect drainage system c) Trap on a subsoil drainage system d) Sewage sumpe Either b) or c) Answer: c)