Plumbing 3rd Importance

Question 1

Continuous wastes and fixture tailpieces for lavatories and similar fixtures shall not be less than____________inches O.D.

Answer 1

1-1/4 inches

Lavatories shall have a waste outlet and fixture tailpiece not less than 1-1/4 inches (32 mm) in diameter. Continuous wastes and fixture tailpieces shall be constructed from the materials specified in Section 701.4. Waste outlets shall be provided with an approved topper or strainer.
(2018 UPC - 701.4 Continuous Wastes.)

Question 2

Metered faucets shall deliver not more than____________gallons of water per use.

Answer 2

0.25 gallons

Metered faucets shall deliver a maximum of 0.25 gallons (1.0 L)per metering cycle.

Question 3

Sand and similar interceptors must have a minimum water seal of:

Answer 3

6 inches

Sand and similar interceptors for every solid shall be so designated and located as to be readily accessible for cleaning, shall have a water seal of not less than 6 inches (152 mm), and shall be vented.

Question 4

The waste line in an oil and flammable interceptor must be a minimum of_____________
in diameter with a full-size cleanout to grade.

Answer 4

3 inches

The waste line shall be not less than 3 inches (80 mm) in diameter with a full-size cleanout to grade. Where an interceptor is provided with an overflow, it shall be provided with an overflow line [not less than 2 inches (50 mm) in diameter] to an approved waste oil tank having a minimum capacity of 550 gallons (2082 L) and meeting the requirements of the Authority Having Jurisdiction.

Question 5

Each fixture trap shall have a water seal of not more than_____________inches.

Answer 5

4 inches

Each fixture trap shall have a liquid seal of not less than 2 inches(51 mm) and not more than 4 inches (102 mm), except where a deeper seal is found necessary by the Authority Having Jurisdiction. Traps shall be set true with respect to their liquid seals and, where necessary, they shall be protected from freezing.

Question 6

If a plumbing system is lawfully in existence at the time of the adoption of this code, it is permitted to have its maintenance, repair or use continued, as long as no hazard to_____________
is created by such system.

Answer 6

Life, health, or property

Plumbing systems lawfully in existence at the time of the adoption of this code shall be permitted to have their use, maintenance, or repair continued where the use, maintenance, or repair is in accordance with the original design and location and no hazard to life, health, or property has been created by such plumbing system.

Question 7

What may a reclaimed water system NOT be connected to?

Answer 7

Potable water system

Reclaimed (recycled) water systems shall have no connection to a potable water supply or alternate water source system. Potable water is permitted to be used as makeup water for a reclaimed(recycled) water storage tank provided the water supply inlet is protected by an air gap or reduced-pressure principle backflow preventer in accordance with this code.

Question 8

What is the minimum clearance in front of water heater service panels mounted in an enclosure on the roof?

Answer 8

30 inches

Appliances on roofs shall be designed or enclosed so as to withstand climatic conditions in the area in which they are installed. Where enclosures are provided, each enclosure shall permit easy entry and movement, shall be of reasonable height, and shall have not less than a 30 inch (762 mm) clearance between the entire service access panel(s) of the appliance and the wall of the enclosure. [NFPA 54:9.4.1.1]
(NFPA 54: National Fuel Gas Code)

Question 9

In cold climate areas, backflow assemblies and devices shall be protected from_______________by a method acceptable to the Authority Having Jurisdiction.

Answer 9

Freezing

In cold climate areas, backflow assemblies and devices shall be protected from freezing with an outdoor enclosure that complies with ASSE 1060 or by a method acceptable to the Authority Having Jurisdiction.

Question 10

Forced draft systems shall be designed and constructed so as to develop a______________flow adequate to remove flue or vent gases to the outside atmosphere.

Answer 10

Positive

Forced draft systems and portions of induced draft systems under positive pressure during operation shall be designed and installed so as to prevent leakage of the flue or vent gases into a building.
[NFPA 54:12.4.3.3]
(NFPA 54: National Fuel Gas Code)

Question 11

What is defined as an assembly of listed semirigid or flexible tubing and fittings to carry fuel between a fuel piping outlet and a fuel-burning appliance?

Answer 11

Appliance Fuel Connector

An assembly of listed semi-rigid or flexible tubing and fittings to carry fuel between a fuel piping outlet and a fuel-burning appliance

Question 12

Rainwater tank openings must be protected to prevent the entrance of_________________into the tank.

Answer 12

All the above

Rainwater tank openings shall be protected to prevent the entrance of insects, birds and rodents into the tank. Rainwater tank access openings exceeding 12 inches (305 mm) in diameter shall be secured to prevent tampering and unintended entry by either a lockable device or other approved method.

Question 13

Rainwater tank access openings exceeding
__________in diameter must be secured to prevent tampering and unintended entry by either a lockable device or other approved method.

Answer 13

12 inches

Rainwater tank openings shall be protected to prevent the entrance of insects, birds and rodents into the tank. Rainwater tank access openings exceeding 12 inches (305 mm)in diameter shall be secured to prevent tampering and unintended entry by either a lockable device or other approved method.

Question 14

What is the minimum flow rate per outlet for nitrogen?

Answer 14

15 cfm

Medical gas and vacuum systems shall be capable of supplying the flow rates listed in Table 1305.2.

Question 15

Listed flexible copper water connectors shall be installed in____________locations, unless
otherwise listed.

Answer 15

Readily accessible

Flexible water connectors shall be installed in readily accessible locations, and where under continuous pressure shall comply with ASME A112.8.6/CSA B125.6. Flexible water connectors with an excess flow shutoff device shall comply with CSA B125.5/APMO Z600.

Question 16

What is the minimum distance between a gray water disposal field and a septic tank?

Answer 16

5 feet

No gray water system or part thereof shall be located on a lot other than the lot that is the site of the building or structure that discharges the gray water, nor shall a gray water system or part thereof be located at a point having less than the minimum distance indicated in Table 1503.4.

Question 17

True or False: Where exhaust fans, clothes dryers and kitchen ventilation systems interfere with the operation of appliances, makeup air must be provided.

Answer 17

True

Where exhaust fans, clothes dryers, and kitchen ventilation systems interfere with the operation of appliances, makeup air shall be provided. [NFPA 54:9.3.1.5]
(NFPA 54: National Fuel Gas Code)

Question 18

Floor-mounted fixtures must be rigidly secured to the drainage connection (and to the floor)by screws or bolts of:

Answer 18

Copper or copper alloy

Floor-outlet or floor-mounted fixtures shall be rigidly secured to the drainage connection and to the floor, where so designed, by screws or bolts of copper, copper alloy, or other equally corrosion-resistant material.

Question 19

Where a fixture comes in contact with the wall or floor, the joint between the fixture and the wall or floor shall be made___________.

Answer 19

Watertight

When a fixture comes in contact with the wall or floor, the joint between the fixture and the wall or floor shall be made watertight.

Question 20

After-coolers, dryers, receivers, and separators, must be equipped with:

Answer 20

Drains

Drains shall be installed on dryers, after-coolers, separators, and receivers.

Question 21

Heat exchangers used for heat transfer, heat recovery, or solar heating shall protect the potable water system from being____________ by the heat transfer medium.

Answer 21

Contaminated

Heat exchangers used for heat transfer, heat recovery, or solar heating shall protect the potable water system from being contaminated by the heat-transfer medium. Single-wall heat exchangers used in indirect-fired water heaters shall meet the requirements of Section 505.4.1. Double-wall heat exchangers shall separate the potable water from the heat-transfer medium by providing a space between the two walls that are vented to the atmosphere.

Question 22

Unless it can be demonstrated that the fire-resistive rating of the penetration is maintained, unshielded couplings may not be used to connect:

Answer 22

Noncombustible piping

Unshielded couplings shall not be used to connect noncombustible piping unless it is capable of being demonstrated that the fire-resistive integrity of the penetration is maintained.

Question 23

Where can subsoil drains be piped to?

Answer 23

Alley, storm drain, street curb

Subsoil drains shall be piped to a storm drain, to an approved water course, to the front street curb or gutter, to an alley, or the discharge from the subsoil drains shall be conveyed to the alley by a concrete gutter. Where a continuously flowing spring or groundwater is encountered, subsoil drains shall be piped to a storm drain or an approved water course.

Question 24

Where should medical gas and medical vacuum risers NOT be located?

Answer 24

Elevator shafts

Piping shall not be installed in kitchens, elevator shafts, elevator machine rooms, areas with open flames, electrical service equipment exceeding 600 volts, and areas prohibited under NFPA 70 except for the following locations:
(1) Room locations for medical air compressor supply systems and
medical-surgical vacuum pump supply systems.
(2) Room locations for secondary distribution circuit panels and breakers
having a voltage rating not exceeding 600 volts. [NFPA 99:5.1.10.11.3.2]
(NFPA 99: Health Care Facilities Code)

Question 25

From the fixture outlet of a bar sink to the receptor, developed lengths may not be more than.

Answer 25

5 feet

Where the sink in a bar, soda fountain or counter is so located that the trap serving the sink cannot be vented, the sink drain shall discharge through an air gap or an air break (see Section
801.3.3)into an approved receptor that is vented. The developed length from the fixture outlet to the receptor shall not exceed 5 feet (1524 mm).

Question 26

Food preparation sinks, steam kettles, potato peelers, ice cream dipper wells, and similar equipment shall be indirectly connected to the drainage system by means of an_______________.

Answer 26

Airgap

Food-preparation sinks, steam kettles, potato peelers, ice cream dipper wells and similar equipment shall be indirectly connected to the drainage system by means of an air gap. Bins, sinks, and other equipment having drainage connections and used for the storage of unpackaged ice used for human ingestion, or used in direct contact with ready-to-eat food, shall be indirectly connected to the drainage system by means of an air gap. Each indirect waste pipe from food-handling fixtures or equipment shall be separately piped to the indirect waste receptor and shall not combine with other indirect waste pipes. The piping from the equipment to the receptor shall be not less than the drain on the unit, and in no case less than 1/2 of an inch (15 mm).

Question 27

A pump meant to supply water to trap primers, urinals, and water closets must be able to deliver at least____________ residual pressure at the most remote and highest outlet.

Answer 27

15 psi

Pumps serving rainwater catchment systems shall be listed. Pumps supplying water to water closets, urinals, and trap primers shall be capable of delivering not less than 15 pounds-force per square inch (psi) (103 kPa) residual pressure at the highest and most remote outlet served.

Question 28

Plastic gas piping shall installed outside, ________________only.

Answer 28

Underground

Plastic piping shall be installed outdoors, underground only.
Exceptions:
(1) Plastic piping shall be permitted to terminate above ground where an anode-less riser is used.
(2) Plastic piping shall be permitted to terminate with a wall head adapter aboveground in buildings, including basements, where the plastic piping is inserted in a piping material permitted for use in buildings. [NFPA
54:7.1.7.1]
(NFPA 54: National Fuel Gas Code)

Question 29

The building drain shall extend _____________feet outside of the building walls before connecting to the sewer?

Answer 29

2 feet.

That part of the lowest piping of a drainage system that receives the discharge from soil, waste, and other drainage pipes inside the walls of the building and conveys it to the building sewer beginning 2 feet (610 mm) outside the building wall.

Question 30

What is required for threaded joints in medical gas piping systems?

Answer 30

Tapered pipe thread complying with ASME B1.20.1

(2) They shall be tapered pipe threads complying with ASME

Question 31

True or False: Each plumbing fixture shall be provided with an adequate supply of potable running water arrange as to flush and keep it clean and sanitary without danger of backflow or cross-connection.

Answer 31

True

Except where not deemed necessary for safety or sanitation by the Authority Having Jurisdiction, each plumbing fixture shall be provided with an adequate supply of potable running water piped thereto in an approved manner, so arranged as to flush and keep it in a clean and sanitary condition without danger of backflow or cross-connection. Water closets and urinals shall be flushed by means of an approved flush tank or flushometer valve.

Question 32

Water heaters installations in bedrooms and bathrooms shall be of the_______________type.

Answer 32

Direct-vent

(2) Water heater shall be of the direct vent type [NFPA
54:10.27.1(2)]
(NFPA 54: National Fuel Gas Code)

Question 33

Fuel-burning water heaters are permitted to be installed in a closet located in the:

Answer 33

Bedroom or bathroom

(1) Fuel-burning water heaters shall be permitted to be installed in a closet located in the bedroom or bathroom provided the closet is equipped with a listed, gasketed door assembly and a listed self-closing device. The self-closing door assembly shall meet the requirements of Section 504.1.1.
The door assembly shall be installed with a threshold and bottom door seal and shall meet the requirements of Section 504.1.2. Combustion air for such installations shall be obtained from the outdoors in accordance with Section 506.4. The closet shall be for the exclusive use of the water heater.

Question 34

What is the maximum downstream pressure from a pump serving a gray water irrigation field?

Answer 34

20 psi

Where pressure at the discharge side of the pump exceeds 20pounds-force per square inch (psi) (138 kPa), a pressure-reducing valve able to maintain downstream pressure not exceeding20 psi (138 kPa) shall be installed downstream from the pump and before an emission device.

Question 35

Shutoff valves serving decorative gas appliances shall be________________to be installed in fireplaces if listed for such use.

Answer 35

Permitted

Each appliance connected to a piping system shall have an accessible, approved manual shutoff valve with a nondisplaceable valve member or a listed gas convenience outlet. Appliance shutoff valves and convenience outlets shall serve a single appliance only. The shutoff valve shall be located within 6 feet (1829 mm)of the appliance it serves. Where a connector is used, the valve shall be installed upstream of the connector. A union or flanged connection shall be provided downstream from the valve to permit removal of appliance controls. Shutoff valves serving decorative appliances shall be permitted to be installed in fireplaces if listed for such use. [NFPA 54:9.6.5, 9.6.5.1(A)(B)] (NFPA 54: National Fuel Gas Code)

Question 36

Plastic pipe and the fittings used for plastic pipe, other than those for gas, must meet the requirements of:

Answer 36

NSF 14

Plastic pipe, plastic pipe fittings, and components other than those for gas, shall meet the requirements of NSF 14.

Question 37

Non-metallic sub-pans or linings may be built-up on the job site of not less than 3 layers of standard grade__________________pound asphalt impregnated roofing felt.

Answer 37

15 pound

Nonmetallicshower sub pans or lining shall be permitted to be built up on the job site of not less than three layers of standard grade 15 pound (6.8 kg) asphalt impregnated roofing felt. The bottom layer shall be fitted to the formed subbase and each succeeding layer thoroughly hot-mopped to that below. Corners shall be carefully fitted and shall be made strong and watertight by folding or lapping. and each corner shall be reinforced with suitable webbing hot-mopped in place.

Question 38

Plumbing fixtures must be constructed of________________material.

Answer 38

Dense, durable, non-absorbent

Plumbing fixtures shall be constructed of dense, durable, non-absorbent materials and shall have smooth, impervious surfaces, free from unnecessary concealed fouling surfaces.

Question 39

Drinking fountains may be installed with_______________wastes.

Answer 39

Indirect

Drinking fountains shall be permitted to be installed with indirect waste

Question 40

Not more than_____________ trap shall be permitted on a trap arm.

Answer 40

One

Each plumbing fixture, shall be separately trapped by an approved type of liquid seal trap. This section shall not apply to fixtures with integral traps. Not more than one trap shall be permitted on a trap arm.

Question 41

The minimum size of any piping outlet for a mobile home shall be___________ inch.

Answer 41

3/4 inch

The size of the supply piping outlet for a gas appliance shall be not less than 1/2 of an inch in diameter (15 mm).
The size of a piping outlet for a mobile home shall be not less than3/4 of an inch in diameter (20 mm).

Question 42

Fixtures shall be so designed that they are free from concealed___________surface.

Answer 42

Fouling

Plumbing fixtures shall be constructed of dense, durable, non-absorbent materials and shall have smooth, impervious surfaces, free from unnecessary concealed fouling surfaces.

Question 43

Automatically controlled flushometer valves may be substituted for________________.

Answer 43

Flush tanks

Except where not deemed necessary for safety or sanitation by the Authority Having Jurisdiction, each plumbing fixture shall be provided with an adequate supply of potable running water piped thereto in an approved manner, so arranged as to flush and keep it in a clean and sanitary condition without danger of backflow or cross-connection. Water closets and urinals shall be flushed by means of an approved flush tank or flushometer valve.

Question 44

True or False: No building supply shall be located in any lot other than the lot which is the site of the building or structure served by such building supply.

Answer 44

True

Except as provided in Section 609.7, no building supply shall be located in a lot other than the lot that is the site of the building or structure served by such building supply.
(2018 UPC - 609.7 Abutting Lot.)

Question 45

Where practical, all pipes from fixtures shall be run to the_____________ wall.

Answer 45

Nearest

Plumbing fixtures shall be installed in a manner to afford easy access for repairs and cleaning. Pipes from fixtures shall be run to the nearest wall.

Question 46

The minimum wall thickness (schedule) of galvanized steel pipe that is allowed for an above grade sanitary or rainwater drainage system is:

Answer 46

Schedule 40

Pipe, tube, and fittings conveying rainwater shall be of such materials and design as to perform their intended function to the satisfaction of the Authority Having Jurisdiction. Conductors within a vent or shaft shall be of cast-iron, galvanized steel, wrought iron, copper, copper alloy, lead,
Schedule 40 ABS DWV, Schedule 40 PVC DWV, stainless steel 304 or 316L [stainless steel 304 pipe and fittings shall not be installed underground and shall be kept not less than 6 inches (152 mm) aboveground], or other approved materials, and changes in direction shall be in accordance with the requirements of Section 706.0.

Question 47

Access to a water heater, on the roof, by a trap door, shall not be less than______________inches.

Answer 47

22 inches x 24 inches.

The inside means of access shall be a permanent or fold away inside stairway or ladder, terminating in an enclosure, scuttle, or trap door. Such scuttles or trap doors shall be at least 22 inches by 24 inches (559 mm by 610 mm) in size, shall open easily and safely under all conditions, especially snow; and shall be constructed so as to permit access from the roof side unless deliberately locked on the inside.

Question 48

When the requirements within the jurisdiction of this Plumbing Code conflict with the requirements of the Mechanical code ,______________shall prevail.

Answer 48

This code

Where the requirements within the jurisdiction of this plumbing code conflict with the requirements of the mechanical code, this code shall prevail. In instances where this code, applicable standards, or the manufacturer’s installation instructions conflict, the more stringent provisions shall prevail. Where there is a conflict between a general requirement and a specific requirement, the specific requirement shall prevail.

Question 49

Female PVC screwed fittings for water piping shall be used with plastic male fittings and plastic male_______________only.

Answer 49

Threads

Threads shall comply with ASME B1.20.1. A minimum of Schedule 80 shall be permitted to be threaded. Molded threads on adapter fittings for transition to threaded joints shall be permitted. Thread sealant compound that is compatible with the pipe and fitting, insoluble in water and nontoxic shall be applied to male threads. The joint between the pipe and transition fitting shall be of the solvent cement type. Caution shall be used during assembly to prevent over tightening of the PVC components once the thread sealant has been applied. Female PVC threaded fittings shall be used with plastic male threads only.

Question 50

Condensate or waste water shall not drain over a ___________________.

Answer 50

Public way

Condensate from air washers, air-cooling coils, condensing appliances, and the overflow from evaporative coolers and similar water-supplied equipment or similar air-conditioning equipment shall be collected and discharged to an approved plumbing fixture or disposal area. Where discharged into the drainage system, equipment shall drain by means of an indirect waste pipe. The waste pipe shall have a slope of not less than 1/8 inch per foot (10.4 mm/m) or 1 percent slope and shall be of approved corrosion-resistant material not smaller than the outlet size in accordance with Section 814.3 or Section 814.4 for air-cooling coils or condensing appliances, respectively. Condensate or wastewater shall not drain over a public way.

Question 51

All piping passing under or through walls shall be protected from_____________.

Answer 51

Breakage

Piping passing under or through walls shall be protected from breakage. Piping passing through or under cinders or other corrosive materials shall be protected from external corrosion in an approved manner. Approved provisions shall be made for expansion of hot water piping. Voids around piping passing through concrete floors on the ground shall be sealed.

Question 52

Which of the following should supply outdoor combustion air?

Answer 52

One or two permanent openings.

Two permanent openings, one commencing within 12 inches (305mm) of the top and one commencing within 12 inches (305 mm) of the bottom of the enclosure shall be provided.

Question 53

Combination stop-and-waste valves or cocks shall not be installed_____________.

Answer 53

Underground

Potable water outlets, freeze-proof yard hydrants, combination stop-and-waste valves, or other fixtures that incorporate a stop and waste feature that drains into the ground shall not be installed underground.

Question 54

Required combustion air ducts shall not be less than_____________inches in the least dimension.

Answer 54

3 inches

(1) Each opening shall have a free area of not less than 1 square inch per 1000 Btu/h (0.002 m2/kW) of the total input rating of appliances in the space, but not less than 100 square inches (0.065 m2). One opening shall commence within12 inches (305 mm) of the top of the enclosure, and one opening shall commence within 12 inches (305 mm) of the bottom of the enclosure (see Figure 506.3).
The dimension of air openings shall be not less than 3 inches (76 mm).

Question 55

Stormwater shall not be drained into sewers intended for______________drainage only.

Answer 55

Sanitary

Storm water shall not be drained into sewers intended for sanitary drainage.

Question 56

Piping installed above ground shall be securely supported and located where it will be protected from physical:

Answer 56

Damage

Piping installed aboveground shall be securely supported and located where it will be protected from physical damage. Where passing through an exterior wall, the piping shall also be protected from corrosion by coating or wrapping with an inert material approved for such applications.
The piping shall be sealed around its circumference at the point of exterior penetration to prevent the entry of water, insects, and rodents. Where piping is encased in a protective pipe sleeve, the annular spaces between the gas piping and the sleeve and between the sleeve and the wall opening shall be sealed.

Question 57

Attic and underfloor water heater locations shall be provided with an __________ outlet at or near the water heater.

Answer 57

Electric outlet

A permanent 120 V receptacle outlet and a lighting fixture shall be installed near the appliance. The switch controlling the lighting fixture shall be located at the entrance to the passageway. [NFPA
54:9.5.3]
(NFPA 54: National Fuel Gas Code)

Question 58

Water heaters may be vented by means of a mechanical draft system of______________draft design.

Answer 58

Either forced or induced

Appliances requiring venting shall be permitted to be vented by means of mechanical draft systems of either forced or induced draft design. [NFPA 54:12.4.3.2]
(NFPA 54: National Fuel Gas Code)

Question 59

Attic and underfloor water heater locations shall be provided with an ___________fixture at or near the water heater.

Answer 59

Lighting fixture

A permanent 120 V receptacle outlet and a lighting fixture shall be installed near the appliance. The switch controlling the lighting fixture shall be located at the entrance to the passageway. [NFPA
54:9.5.3]
(NFPA 54: National Fuel Gas Code)

Question 60

True or False: In multi-dwelling units, the water supply to each unit must be able to be shut off without stopping water supply or other units.

Answer 60

True

In multidwelling units, one or more shutoff valves shall be provided in each dwelling unit so that the water supply to a plumbing fixture or group of fixtures in that dwelling unit can be shut off without stopping water supply to fixtures in other dwelling units. These valves shall be accessible in the dwelling unit that they control.

Question 61

‘S’ traps, bell traps, and crown-vented traps
shall be_____________.

Answer 61

Prohibited

No form of trap that depends for its seal upon the action of movable parts shall be used. No trap that has concealed interior partitions, except those of plastic, glass, or similar corrosion-resisting material, shall be used. “S” traps, bell traps, and crown-vented traps shall be prohibited. No fixture shall be double trapped. Drum and bottle traps shall be installed for special conditions. No trap shall be installed without a vent, except as otherwise provided in this code.

Question 62

No urinal shall be set closer than________________ inches from its center to any side wall or partition.

Answer 62

12 inches

Fixtures shall be set level and in proper alignment with reference to adjacent walls. No water closet or bidet shall be set closer than 15 inches (381 mm) from its center to a side wall or obstruction nor closer than 30 inches (762 mm) center to center, to a similar fixture.
The clear space in front of a water closet or bidet shall be not less than 24 inches (610 mm). No urinal shall be set closer than 12 inches (305 mm) from its center to a side wall or partition or closer than 24 inches (610 mm) center to center.

Question 63

Caulked joints for cast iron bell-and-spigot soil pipe and other similar joints shall be firmly packed with____________or hemp and filled
with molten lead to a depth of not less than 1”

Answer 63

Oakum

Caulked joints shall be firmly packed with oakum or hemp and filled with molten lead to a depth of not less than 1 inch (25.4 mm)in one continuous pour. The lead shall be caulked thoroughly at the inside and outside edges of the joint. After caulking, the finished joint shall not exceed 1/8 of an inch (3.2 mm) below the rim of the hub. No paint, varnish, or other coatings shall be permitted on the joining material until after the joint has been tested and approved.

Question 64

For each elbow up to and including____________ degrees in the common vent, the maximum common vent capacity listed in the venting tables shall be reduced by 5 percent.

Answer 64

45 degrees

The vent connector capacities listed in the common vent sizing tables include allowance for two 90 degree (1.57 rad) elbows. For each additional elbow up to and including 45 degrees (0.79 rad), the maximum vent connector capacity listed in the venting tables shall be reduced by 5 percent. For each elbow greater than 45 degrees(0.79 rad) up to and including 90 degrees (1.57 rad), the maximum vent connector capacity listed in the venting tables shall be reduced by 10 percent. [NFPA
54:13.2.71
(NFPA 54: National Fuel Gas Code)