ANSI ISA 18.2-2016 pdf free download

ANSI ISA 18.2-2016 pdf free download.Manual of Petroleum Measurement Standards Chapter 18.2 Custody Transfer of Crude Oil from Lease Tanks Using Alternative Measurement Methods.
1 Scope This standard defines the minimum equipment and methods used to determine the quantity and quality of crude oil being loaded from a lease tank to a truck trailer without requiring direct access to a lease tank gauge hatch. Methods and equipment described are grouped by tank zone, trailer zone, and the transition zone between the two (see Section 5). The equipment used for measurement is dependent on the existing design of the lease equipment, the equipment used to transport the product, or a combination of the two. Some sites may require measurements from multiple zones in order to arrive at an accurate load quantity and quality. 2 Normative References The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. API MPMS Chapter 2, Tank Calibration – All relevant sections API MPMS Chapter 3.1 A, Standard Practice for the Manual Gauging of Petroleum and Petroleum Products API MPMS Chapter 3.1 B, Standard Practice for Level Measurement of Liquid Hydrocarbons in Stationary Tanks by Automatic Tank Gauging API MPMS Chapter 3.6, Measurement of Liquid Hydrocarbons by Hybrid Tank Measurement Systems API MPMS Chapter 4, Proving Systems – All relevant sections API MPMS Chapter 5.2, Measurement of Liquid Hydrocarbons by Displacement Meters API MPMS Chapter 5.3, Measurement of Liquid Hydrocarbons by Turbine Meters API MPMS Chapter 5.6, Measurement of Liquid Hydrocarbons by Coriolis Meters API MPMS Chapter 5.8, Measurement of Liquid Hydrocarbons by Ultrasonic Flow Meters API MPMS Chapter 6.1 , Lease Automatic Custody Transfer (LACT) Systems API MPMS Chapter 7, Temperature Determination – All relevant sections
3 Terms and Definitions For the purposes of this document, the following definitions apply. NOTE See API MPMS Chapter 1 , online Terms and Definitions Database, for additional terms and definitions applicable to this document. 3.1 crude oil lease tank A tank that is calibrated per API MPMS Chapter 2 standards that stores crude oil from producing leases waiting to be transported by a carrier. 3.2 crude oil truck driver COTD Assumes that the driver is also the gauger; however, it should be recognized that these duties may be divided between different individuals: a person who only drives the tank truck and a gauger or applicable representative who is responsible for measurement and testing. 3.3 linearized tank table LTT The linearized tank table value corresponding to the opening gauge measurement, closing gauge measurement, and free water gauge measurement. 3.4 merchantability A term applied to liquid hydrocarbons judged to be acceptable for custody transfer to a carrier. The oil is settled and contains no more than a set amount of suspended sediment and water (S&W) and other impurities. The amount of S&W or other impurities shall be agreed upon by both parties to have a mutual understanding of what is merchantable product. 4 Safety Safety is an essential part of crude oil trucking operations both on roadways and during custody transfer. API MPMS Chapter 1 8.1 was developed for applications where access to lease tanks to perform the associated measurement and quality tasks was not restricted and where the settling and weathering of crude oil prior to custody transfer was possible. There are many applications today where these conditions cannot be met. Opening thief hatches of storage tanks can lead to the rapid release of high concentrations of hydrocarbon gases and vapors. Be aware that those may result in very low oxygen levels and toxic and flammable conditions around and over the hatch.