Hot Water Pipe Insulation Sizes

1-Inch Pipes or Less

• Household piping is generally 1-inch diameter. For regular household hot water use a minimum of 1-inch-thick insulation is needed. In a low-pressure steam application, 1 1/2-inch thickness is needed. In a medium-pressure steam situation, use 2-inch pipe insulation, and for high-pressure steam applications, go with a 2 1/2-inch pipe insulation.

1 1/4-Inch to 2-inch Pipes

• Apartments and smaller commercial buildings may use 1 1/4-inch to 2-inch pipe sizes. For these pipe sizes, hot water up to 200 degrees Fahrenheit are covered with 1-inch insulation. In a low-pressure steam application, 1 1/2-inch thickness is needed. In a medium pressure and a high-pressure steam application, use 2 1/2-inch pipe insulation.

2 1/4-Inch to 4-inch Pipes

• Commercial operations commonly use 2 1/4-Inch to 4-inch pipes. For hot water up to 200 F, cover them with 1 1/2-inch insulation. In a low-pressure steam application, 2-inch thickness is used. In medium-pressure applications, use 2 1/2-inch insulation, and when confronted with a high-pressure steam application, 3-inch pipe insulation is required.

5-Inch Pipes and Above

• Industrial applications use 5-Inch pipes and above. For hot-water usage up to 200 F, they must be covered with 1 1/2-inch insulation. In a low-pressure steam application, cover them with 2-inch thickness insulation. For medium-pressure applications, a 3-inch insulation thickness is required, and for high-pressure steam applications, use 3 1/2-inch pipe insulation.