1 HVACR316 - Piping Related Codes Trade Math 1 Related Codes Trade Math 1

2 Related Codes General : All refrigerant piping shall be installed, tested and placed in operation in accordance with code. Pipe Enclosures : Rigid or flexible metal enclosures or pipe ducts shall be provided for soft, annealed copper tubing and used for refrigerant piping erected on the premises and containing other than Group A1 or B1 refrigerants. General : All refrigerant piping shall be installed, tested and placed in operation in accordance with code. Pipe Enclosures : Rigid or flexible metal enclosures or pipe ducts shall be provided for soft, annealed copper tubing and used for refrigerant piping erected on the premises and containing other than Group A1 or B1 refrigerants.

3 Related Codes Condensation : All refrigerating piping and fittings, brine piping and fittings that, during normal operation, will reach a surface temperature below the dew point of the surrounding air, and are located in spaces or areas where condensation will cause a safety hazard to the building occupants, structure, electrical equipment or any other equipment or appliances, shall be protected in an approved manner to prevent such damage.

4 Related Codes Materials for refrigerant pipe & tube: Steel Pipe : Carbon steel pipe with a wall thickness not less than Schedule 80 shall be used for Group A2, A3, B2 or B3 refrigerant liquid lines for sizes 1.5 inches and smaller. Materials for refrigerant pipe & tube: Steel Pipe : Carbon steel pipe with a wall thickness not less than Schedule 80 shall be used for Group A2, A3, B2 or B3 refrigerant liquid lines for sizes 1.5 inches and smaller.

5 Related Codes Carbon steel pipe with a wall thickness not less than Schedule 40 shall be used for Group A1 or B1 refrigerant liquid lines 6 inches or smaller, Group A2, A3, B2 or B3 refrigerant liquid lines sizes 2 inches through 6 inches and all refrigerant suction and discharge lines 6 inches or smaller.

6 Related Codes Copper tube : Copper tube used for refrigerant piping erected on the premises shall be seamless copper tube of Type ACR (hard or annealed) complying with ASTM B 280. Where approved, copper tube for refrigerant piping erected on the premises shall be seamless copper tube of Type K,L or M (drawn or annealed) in accordance with ASTM B 88. Annealed temper copper tube shall not be used in sizes larger than a 2 inch nominal size.

7 Related Codes Copper tubing joints : Copper tubing joints used in refrigerating systems containing Group A2, A3, B2 or B3 refrigerants shall be brazed. Soldered joints shall not be used in such refrigerating systems.

8 Related Codes Aluminum tubing : Type aluminum tubing with high pressure fittings shall not be used with methyl chloride and other refrigerants known to attack aluminum.

9 Related Codes Joints & Refrigerant Containing Parts in Air ducts: Joints and all refrigerant containing parts of a refrigerating system located in an air duct of an air conditioning system carrying conditioned air to and from humanly occupied space shall be constructed to withstand, without leakage, a pressure of 150 percent of the higher of the design pressure or pressure relief valve setting.

10 Related Codes Exposure of Refrigerant Pipe Joints: Refrigerant pipe joints erected on the premises shall be exposed for visual inspection prior to being covered or enclosed.

11 Related Codes Stop Valves : All systems containing more than 6.6 pounds of a refrigerant in systems using positive displacement compressors shall have stop valves installed as follows: −At the inlet of each compressor, compressor unit or condensing unit. −At the discharge outlet of each compressor, compressor unit or condensing unit and of each liquid receiver. Stop Valves : All systems containing more than 6.6 pounds of a refrigerant in systems using positive displacement compressors shall have stop valves installed as follows: −At the inlet of each compressor, compressor unit or condensing unit. −At the discharge outlet of each compressor, compressor unit or condensing unit and of each liquid receiver.

12 Related Codes Exceptions: −Systems that have a refrigerant pump-out function capable of storing the entire refrigerant charge in a receiver or heat exchanger −Systems that are equipped with provisions for pump- out of the refrigerant using either portable or permanently installed recovery equipment. −Self contained systems. Exceptions: −Systems that have a refrigerant pump-out function capable of storing the entire refrigerant charge in a receiver or heat exchanger −Systems that are equipped with provisions for pump- out of the refrigerant using either portable or permanently installed recovery equipment. −Self contained systems.

13 Trade Math How to write and read decimals: −Fractions such as 2/10 and.2 are both read the same, two tenths. When there is one digit at the right of the decimal point, we read the decimal as tenths. If there are two digits at the right of the decimal point, the decimal is in hundredths, three digits is in thousandths, four figures is in ten thousandths. How to write and read decimals: −Fractions such as 2/10 and.2 are both read the same, two tenths. When there is one digit at the right of the decimal point, we read the decimal as tenths. If there are two digits at the right of the decimal point, the decimal is in hundredths, three digits is in thousandths, four figures is in ten thousandths.

14 Trade Math Sample fraction/decimal conversions:

15 Trade Math Practice Exercises 1 Write the following common fractions as decimals: 1. 3/ /1, /10, / /1, / /1,000 Write the following common fractions as decimals: 1. 3/ /1, /10, / /1, / /1,000

16 Trade Math Practice Exercises 1 Answers: Answers:

17 Trade Math Practice Exercises 2 Change the following into fractions: 1) A dowel is.5 inches in diameter. 2)A strip of sheet metal is cut so it is.907 inches wide. 3) The thickness of a template is.145 inches. 4) An insulated wire has a diameter of.091 inches. 5) The insulation around a wire is.0305 inches. Change the following into fractions: 1) A dowel is.5 inches in diameter. 2)A strip of sheet metal is cut so it is.907 inches wide. 3) The thickness of a template is.145 inches. 4) An insulated wire has a diameter of.091 inches. 5) The insulation around a wire is.0305 inches.

18 Trade Math Practice Exercises 2 Answers: 1) 5/10 2) 907/1,000 3) 145/1,000 4) 91/1000 5) 305/10,000 Answers: 1) 5/10 2) 907/1,000 3) 145/1,000 4) 91/1000 5) 305/10,000