"The material in Sections 2-6 was previously presented in several sections of Part 1 of API Recommended Practice 550@ which is now out of print: a. Section 2 - API Recommended Practice 550@ Part I@ Section 1@ ""Flow."" b. Section 3 - API Recommended Practice 550@ Part I@ Section 2@ ""Level."" c. Section 4 - API Recommended Practice 550@ Part I@ Section 4@ ""Pressure."" d. Section 5 - API Recommended Practice 550@ Part I@ Section 3@ ""Temperature."" e. Section 6 - API Recommended Practice 550@ Part I@ Section 8@ ""Seals@ Purges@ and Winterizing."" The procedures for installation of the instruments covered in this recommended practice are based on experience with and evaluation of many installations. They represent the installation practices that yield the most consistently accurate results and have proved to be practical and safe. Process and environmental protection is covered in a general fashion in Section 6. Where required@ specific instances of process and environmental protection are covered in Sections 2 - 5. Tank gauging is outside the scope of Section 3. The applicable publication is referenced in that section. Where appropriate@ installation drawings@ cautionary notes@ and explanations are included. Valves and piping that are typically covered in piping standards have been omitted from most installation drawings."