Maryland Journeyman Plumber / Gas Fitter

Maryland Journeyman Plumber / Gas Fitter — 8 questions (8% of exam)

Key Concepts

IPC scope and applicability (Chapter 1, Part 1) - The code applies to the erection, installation, alteration, repairs, relocation, replacement, addition to, use or maintenance of plumbing systems in the jurisdiction. Fuel gas distribution piping and equipment, fuel-gas-fired water heaters and water heater venting systems are regulated by the International Fuel Gas Code (IPC 101.2, Page 1). Exception: detached one- and two-family dwellings and townhouses not more than three stories high with separate means of egress comply with the IRC. - Conflicts: where a general requirement conflicts with a specific requirement, the specific requirement governs; where different sections specify different materials, methods of construction or other requirements, the most restrictive governs (IPC 102.1, Page 1). - Referenced standards: where conflicts occur between this code and a referenced standard, the provisions of this code apply (IPC 102.8.1). - IFGC scope exclusion:…

Maryland Journeyman Plumber / Gas Fitter (6 questions, 6% of exam)

Key Concepts

Metallic pipe (IFGC Section 403.4) - Cast iron pipe shall not be used (Section 403.4.1). - Steel, stainless steel and wrought-iron pipe shall be not lighter than Schedule 10 and shall comply with the dimensional standards of ASME B36.10M and one of: ASTM A53/A53M, ASTM A106, ASTM A312 (Section 403.4.2, Page 69). - Copper and copper alloy pipe shall not be used if the gas contains more than an average of 0.3 grains of hydrogen sulfide per 100 standard cubic feet (0.7 mg per 100 liters). Threaded copper, copper alloy and aluminum-alloy pipe shall not be used with gases corrosive to such materials (Section 403.4.3, Page 69). - Aluminum-alloy pipe shall comply with ASTM B241 (alloy 5456 prohibited), shall be coated where in contact with masonry, plaster or insulation or subject to repeated wettings, and **shall not be used in exterior…

Maryland Journeyman Plumber / Gas Fitter — 4 questions (4% of exam) All references: IPC 2018, Chapter 10, Traps, Interceptors and Separators

Key Concepts

Fixture traps (Section 1002.1). Each plumbing fixture shall be separately trapped by a liquid-seal trap. The vertical distance from the fixture outlet to the trap weir shall not exceed 24 inches (610 mm); the horizontal distance shall not exceed 30 inches (762 mm), measured from the centerline of the fixture outlet to the centerline of the inlet of the trap. A fixture shall not be double trapped. Exception 2 permits a combination fixture on one trap where one compartment is not more than 6 inches (152 mm) deeper than the other and the waste outlets are not more than 30 inches (762 mm) apart. Exception 3: a grease interceptor may serve as the trap for a single fixture or a combination sink of not more than three compartments, where the…

Key Concepts

Minimum fixture counts (Section 403). Fixtures are provided in the minimum number shown in Table 403.1, based on actual use; occupant load is determined by the International Building Code (403.1). Per Section 403.1.1, "the total occupant load shall be divided in half" to get male and female loads. Table 403.1 footnote a: one fixture is the minimum required "for the number of persons indicated or any fraction of the number of persons indicated." Per Section 403.2, Exception 4, separate facilities for each sex are not required in business occupancies where the maximum occupant load is 25 or fewer.

Fixture clearances and setting (Section 405). Not less than 21 inches clearance in front of a water closet, urinal, lavatory or bidet to any wall, fixture or door (405.3.1). Floor flanges: not less than 0.125 inch thick for copper alloy, 0.25 inch for plastic, and 0.25 inch with a 2-inch caulking depth for cast…

Maryland Journeyman Plumber / Gas Fitter — 8 questions (8% of exam)

Key Concepts

Backflow prevention - Pressure vacuum breaker assembly: critical level not less than 12 inches above all downstream piping and outlets (UPC 608.14.5; IPC 2018 608.14.5). - Pipe-applied atmospheric-type vacuum breakers: not less than 6 inches above the flood level rim of the fixture, receptor or device served (IPC 2018 608.16.4). Deck-mounted or integral vacuum breakers: 1 inch (IPC 2018 608.16.4.1). - Vacuum breakers for hose connections in health care or laboratory areas: not less than 6 feet above the floor; bedpan washer hoses: 5 feet (UPC 608.3.1). - Barometric loop: precedes the point of connection and extends vertically to 35 feet; usable only as an atmospheric-type or pressure-type vacuum breaker (UPC 608.14.4; IPC 2018 608.14.4). - Reduced pressure principle assembly relief opening: discharges by air gap and shall be prevented from being submerged (IPC 2018 608.14.2). - Pressure vacuum breaker…

(IPC 2018)

Key Concepts

Cross connections - Cross connections in a potable water supply system are prohibited, except where approved backflow prevention assemblies, backflow prevention devices or other means or methods are installed to protect the potable water supply (IPC 2018, 608.7). - Cross connections between a private water supply and a potable public supply are prohibited — no backflow preventer makes this acceptable (608.7.1).

Hazard classification - "High hazard" = contamination as defined in Section 202 (substances that could cause illness or death). "Low hazard" = pollution as defined in Section 202 (aesthetically objectionable, not necessarily dangerous to health) (Table 608.1 footnotes).

Device ratings (Table 608.1) - Double check backflow prevention assembly (ASSE 1015) — low hazard only; protects against backpressure and backsiphonage. - Backflow preventer for carbonated beverage machines (ASSE 1022) — low hazard only; backpressure and backsiphonage. - Dual check backflow preventer (ASSE 1024 or CSA B64.6) — low hazard (pollution);…

Key Concepts

Slope. Horizontal drainage piping is installed in uniform alignment at uniform slopes. Minimum slopes (Table 704.1): 2½ inches or less — ¼ inch per foot; 3 to 6 inches — 1/8 inch per foot; 8 inches or larger — 1/16 inch per foot. Where the drainage piping is upstream of a grease interceptor, the slope shall be not less than ¼ inch per foot (2-percent slope), regardless of size (Section 704.1).

Pipe size and connections. Size shall not be reduced in the direction of flow; a 4-inch by 3-inch water closet flange is not considered a reduction (Section 704.2). Horizontal branches shall connect to the bases of stacks not less than 10 times the diameter of the drainage stack downstream (Section 704.3).

Key Concepts

Materials & installation - Cast-iron pipe shall not be used (403.4.1). Copper tubing joints shall be brazed with material having a melting point in excess of 1,000°F; brazing alloys shall not contain more than 0.05-percent phosphorus (403.10.2). - Shield plates protecting concealed piping in light-frame assemblies shall be steel not less than 0.0575 inch (No. 16 gage) (404.7.3). Exception: black steel and galvanized steel piping are not required to be protected (404.7). - Underground piping: minimum 12 inches below grade; individual lines to outdoor lights, grills and similar appliances not less than 8 inches where approved and not susceptible to damage (404.12, 404.12.1). - Shutoff valves are prohibited in concealed locations and furnace plenums (409.1.2). - Support intervals, Table 415.1: 1/2-inch steel — 6 ft; 3/4 or 1 inch — 8 ft; 1-1/4 inch or larger horizontal — 10 ft; vertical — every floor level.

Key Concepts

Fitting allowances. For a threaded fitting, the fitting allowance = center-to-face (A) − thread-in/thread engagement (B); the total allowance for an assembly adds this for each fitting opening involved (Pages 40–41). For copper, the allowance (G) = center-to-face − depth of the solder cup (Pages 44–45). For butt-weld fittings: long-radius 90° elbow = 1½ times the pipe size; short-radius 90° elbow and butt-weld tee = 1 times the pipe size; 45° elbow = ⅝ times the pipe size, plus an additional ⅛ inch for weld penetration (Pages 52, 54).

Cut length sequence. (1) Obtain center-to-center from the drawing or field measurement; (2) subtract the total fitting allowance to get end-to-end length (Pages 38–41).