The purpose of IOGP S-728 specification documents is to define a minimum common set of requirements for the procurement of reciprocating positive displacement pumps in accordance with API Standard 674 Positive Displacement Pumps—Reciprocating, Third Edition, December 2010, including Errata 2, April 2015, reaffirmed November 2016 for application in the petroleum and natural gas industries. The IOGP S-728 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.