API MPMS 17.11 -2016 pdf download.Manual of Petroleum Measurement Standards Chapter 17.11 Measurement and Sampling of Cargoes On Board Tank Vessels Using Closed and Restricted Equipment El Hydrocarbon Management HM 52.
1 Scope This document provides guidance on the use, maintenance, and calibration of restricted and closed measurement and sampling equipment. It also provides guidance on preferred size and positioning for gauging and sampling fittings on vessels. 2 Normative References This document should be used in conjunction with the following referenced documents. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. API Manual of Petroleum Measurement Standards (MPMS) Chapter 1 , Vocabulary API MPMS Chapter 2, Tank Calibration API MPMS Chapter 3.1 A-2005, Manual Gauging of Petroleum and Petroleum Products API MPMS Chapter 7, Temperature Determination API MPMS Chapter 8.1, Manual Sampling of Petroleum and Petroleum Products API MPMS Chapter 1 7.4, Method of Quantification of Small Volumes on Marine Vessels (OBQ/ROB) API Recommended Practice 2003, Protection Against Ignitions Arising Out of Static, Lightning, and Stray Currents EI HM 4, Manual Level Measurement for Petroleum Liquids ISO 31 70:2004 1 , Petroleum Liquids—Manual Sampling 3 Terms and Definitions For the purposes of this document, the following definitions apply. 3.1 air-saturated vapor pressure ASVP The observed pressure exerted in vacuo by air-saturated petroleum products, components, and feedstocks, in the absence of undissolved water. 3.2 assay The procedure to determine the presence, absence, or quantity of one or more components. 3.3 dead bottom sample A sample obtained from the lowest accessible point in a tank.
3.4 decanting To pour (a liquid) from one container into another. 3.5 density For a quantity of a homogeneous substance, the ratio of its mass to its volume. The density varies as the temperature changes and is therefore generally expressed as the mass per unit of volume at a specified temperature. 3.6 flash point The minimum temperature to which a product shall be heated for the vapors emitted to ignite momentarily in the presence of a flame when operating under standardized test conditions and for the flame to propagate across the liquid surface. 3.7 inert gas Gas that does not react with the surroundings. 3.8 inerting A procedure used to reduce the oxygen content of a vessel’s cargo spaces by introducing an inert gas such as nitrogen or carbon dioxide or a mixture of gases such as processed flue gas. 3.9 portable sampling unit PSU Intrinsically safe device used in conjunction with a vapor control valve to obtain required cargo samples under closed or restricted system conditions. 3.10 portable measurement unit PMU Intrinsically safe device used in conjunction with a vapor control valve to obtain required liquid level and/or temperatures under closed or restricted system conditions. 3.11 on board quantity OBQ Refers to materials present in a vessel’s cargo tanks, void spaces, and/or pipelines before the vessel is loaded. On board quantity includes a combination of water, oil, slops, oil residue, oil/water emulsions, sludge, and sediment. 3.12 remaining on board ROB Material remaining in a vessel’s cargo tanks, void spaces, and/or pipelines after the cargo is discharged. ROB includes any combination of water, oil, slops, oil residue, oil/water emulsions, sludge, and sediment. 3.13 standpipe A vertical section of pipe extending from the top of a marine vessel tank through which measurements and samples of tank contents can be obtained.
3.14 static accumulator oils Oils having a conductivity of less than 50 pS/m; these oils relax (dissipate charge) slowly. 3.15 UTI Ullage, temperature, and interface 3.16 vapor control valve VCV Valve fitted on a standpipe, expansion trunk, or the deck that permits use of the portable handheld gauging instruments while restricting the release of vapors into the atmosphere. 3.17 vapor pressure RVP, TVP Reid vapor pressure (RVP): The vapor pressure of a liquid at 1 00 ° F (37.8 ° C, 311 ° K) as determined by ASTM D323. True vapor pressure (TVP): The pressure at which the fluid is in equilibrium between its liquid and gas state. 3.18 volatile organic compounds VOCs Organic chemicals that have a high vapor pressure and easily form vapors at normal temperature and pressure. 3.19 washing, crude oil COW Use of a high pressure stream of the crude oil cargo to dislodge or dissolve clingage and sediment from the bulkheads, bottom, and internal tank structures of a vessel during the discharge operation. 4 Health and Safety Precautions 4.1 General Personnel involved with the gauging and sampling of petroleum and petroleum-related substances should be familiar with their physical and chemical characteristics, including potential for fire, explosion, and reactivity, and with the appropriate emergency procedures as well as potential toxicity and health hazards. Personnel should comply with the individual company safe operating practices and with local, state, federal, and national regulations, including the use of appropriate protective clothing and equipment. Personnel involved in inspection, measurement, and/or sampling on board a vessel using equipment via a vapor control valve (VCV) shall at all times be accompanied by a designated ship’s representative.