This document establishes the standards for dimensions@ coupling action@ activation@ and other requirements necessary to achieve full interchangeability between components of various manufactures. It also recommends other optional features which component manufactures should consider@ if they are to satisfy the full scope of users existing requirements. Purpose This standard and accompanying recommendations are intended to achieve the following: ?Establish the acceptable structure and operating integrity of the components involved. ?Provide a uniform coupling configuration and arrangement at the hydrant pit which will permit interchangeability between the components of different manufactures. ?Maximize standardization by recognizing and considering to the fullest extent possible the requirements of other applications (e.g. API-RP1004 Tank Vehicle Bottom Loading and Unloading). ?Assist component manufactures in their design efforts by setting forth those features of components which are considered desirable based upon experience in aircraft fueling. ?Describe the alternative arrangements of hydrant pit components that are typical for four inch hydrant systems and thereby assist component manufactures and aircraft fueling system operators in their efforts.