Type L copper tubing is often used for domestic water service, natural gas, compressed air or fire protection. It has certain specifications set out by the American Society for Testing and Materials, or ASTM. Type L copper tubing is available in annealed or drawn form. The annealed form has been treated with heat to strengthen it, while the drawn has merely been formed into lengths of tubing and is softer.
Type L copper tubing is available in coils or straight lengths. Drawn copper tubing is not available in coils, but annealed tubing is available in diameters from 1/4-inch to 2-inches. Coil lengths range from 40 or 45 feet for 2-inch tubing to 100 feet for 1/4-inch to 1-inch tubing. Drawn and annealed tubing is available in straight lengths; up to 20 feet long for 1/4-inch to 10-inch tubes and 18 feet for 12-inch tubing. The wall thickness for type L tubing ranges from .03 inches for the 1/4-inch tubing to .28 inches for 12-inch tubing. 1/4-inch tube weighs .13 pounds per linear foot, while 12-inch tubing weighs 40.4 pounds per linear foot.
Each size of type L copper tubing has a specific capacity for liquid. These capacities range from .004 gallons per linear foot for 1/4-inch tubing to 5.45 gallons for 12-inch tubing. In cubic feet, the capacities range from .0005 to .73 cubic feet per linear foot. The weight of the tubing when it is filled with water ranges from .16 pounds per linear foot for 1/4-inch tubing to 85.8 pounds per linear foot for 12-inch tubing.
Rated Internal Working Pressure
The rated internal working pressure is based on the formula set by the ASTM. This formula includes the maximum allowable stress the pipe can be under, the wall thickness and the outside diameter of the tubing. The rating also includes a working temperature. The working temperature of the copper tubing can be up to 400 degrees Fahrenheit. Annealed copper tubing can have maximum stress from 3,000 to 6,000 pounds per square inch. Drawn tubing can have stress from 9,400 to 10,300 psi. The lowest rated internal working pressure for annealed tubing is 253 psi for 12-inch pipe and the highest rating is 912 psi for 1/4-inch tubing. 12-inch drawn copper tubing has a minimum rating of 397 psi and 1/4-inch tubing has a maximum rating of 1,569 psi.
Actual Burst Pressures
The rated internal working pressure is much lower than the actual pressure that will cause the tubing to burst. Annealed copper tubing will burst at between 3,885 psi for 1/2-inch pipe and 1,910 psi for 2-inch pipe. A 1/2-inch drawn tubing will burst at 7,765 psi and 8-inch drawn tubing will burst at 2,650 psi. These pressures are an average of three tests performed on every available type and sizes of tubing.