The purpose of the IOGP S-713 specification documents is to define a minimum common set of requirements for the procurement of special-purpose gears in accordance with API Standard 613, Sixth Edition, July 2021, Special-purpose Gears for Petroleum, Chemical and Gas Industry Services, for application in the petroleum and natural gas industries. The IOGP S-713 specification documents follow a common structure comprising a specification, also known as a technical requirements specification (TRS), a procurement data sheet (PDS), an information requirements specification (IRS) and a quality requirements specification (QRS). These four specification documents, together with the purchase order, define the overall technical specification for procurement.