Manual of Petroleum Measurement Standards Chapter 5—Metering

Section 1—General Considerations for

Measurement by Meters

FOURTH EDITION, SEPTEMBER 2005 ERRATA 1, JUNE 12, 2008

ERRATA 2, JUNE 27, 2011

REAFFIRMED, JULY 2016

Manual of Petroleum Measurement Standards Chapter 5—Metering

Section 1—General Considerations for Measurement by Meters

Measurement Coordination

FOURTH EDITION, SEPTEMBER 2005 ERRATA 1, JUNE 12, 2008

ERRATA 2, JUNE 27, 2011

REAFFIRMED, JULY 2016

SPECIAL NOTES

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Copyright © 2005 American Petroleum Institute

FOREWORD

Chapter 5 of the API Manual of Petroleum Measurement Standards (API MPMS) pro- vides recommendations, based on best industry practice, for the custody transfer metering of liquid hydrocarbons. The various sections of this Chapter are intended to be used in con- junction with API MPMS Chapter 6 to provide design criteria for custody transfer metering encountered in most aircraft, marine, pipeline, and terminal applications. The information contained in this chapter may also be applied to non-custody transfer metering.

The chapter deals with the principal types of meters currently in use: displacement meters, turbine meters and Coriolis meters. If other types of meters gain wide acceptance for the measurement of liquid hydrocarbon custody transfers, they will be included in subsequent sections of this chapter.

Nothing contained in any API publication is to be construed as granting any right, by implication or otherwise, for the manufacture, sale, or use of any method, apparatus, or prod- uct covered by letters patent. Neither should anything contained in the publication be con- strued as insuring anyone against liability for infringement of letters patent.

This document was produced under API standardization procedures that ensure appropri- ate notification and participation in the developmental process and is designated as an API standard. Questions concerning the interpretation of the content of this publication or com- ments and questions concerning the procedures under which this publication was developed should be directed in writing to the Director of Standards, American Petroleum Institute, 1220 L Street, N.W., Washington, D.C. 20005. Requests for permission to reproduce or translate all or any part of the material published herein should also be addressed to the director.

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iii

CONTENTS

Page

1. INTRODUCTION 1

2. SCOPE 1

   1. Field of Application 1

3. REFERENCED PUBLICATIONS 1

4. CONSIDERATIONS FOR THE DESIGN OF METER INSTALLATIONS 1

5. FACTORS TO CONSIDER IN SELECTING METERS AND

   METER ACCESSORY EQUIPMENT 2

6. GUIDELINES FOR SELECTING TYPE OF METER 2

   1. Displacement Meters 3

   2. TurbineMeters 3

   3. Coriolis Meters 4

7. INSTALLATION 4

   1. Valves 4

   2. Piping Installation 4

   3. Electrical Installations 6

8. METER PERFORMANCE 6

9. METER OPERATION AND MAINTENANCE 7

   1. Conditions That Affect Operations 7

   2. Precautions for Operating Newly Installed Meters 7

   3. Instructions for Operating Meter Systems 7

   4. Meter Proving 7

   5. Methods of Controlling Meter Factors 8

   6. Meter Maintenance 8

Figures

1. Selection Guide for Displacement and Turbine Meters 3

2. Turbine Meter Performance Characteristics 6

v

Manual of Petroleum Measurements Standards Chapter 5—Metering

Section 1—General Considerations for Measurement by Meters

1. Introduction

   API MPMS Chapter 5 covers the general installation and operation of meters and accessory equipment, without respect to the arrangements necessary to meet special problems. The guidelines are common to all metering systems, but appropri- ate precautions should be taken when they are used for spe- cialized metering systems, as discussed in API MPMS Chapter 6, “Metering Assemblies,” and for mass measure- ment, as discussed in API MPMS Chapter 14.8, “Liquefied Petroleum Gas Measurement.”

   Some of the advantages of metering are as follows:

   1. Metering can increase the availability of tanks, since no tank needs to be isolated for the sole purpose of measurement.

   2. Metering lends itself to the calculation, indication, and dis- play of instantaneous flow rate and volume.

   3. Metering can deliver a measured volume taken from sev- eral sources at the same time into a single receiver, or it can deliver a measured volume taken from a single source into several receivers.

   4. Metering accuracy can be readily checked by the use of standard references.

   5. Metering allows dynamic volume averaging of tempera- tures and samples to be applied to volumes.

   This publication does not endorse or advocate the preferen- tial use of any specific type of equipment or systems, nor is it intended to restrict future development of such equipment.

   
   

2. Scope

   API MPMS Chapter 5 is intended to be a guide for the proper specification, installation, and operation of meter runs designed to dynamically measure liquid hydrocarbons so that acceptable accuracy, service life, safety, reliability, and qual- ity control can be achieved. API MPMS Chapter 5 also includes information that will assist in troubleshooting and improving the performance of meters.

   
   

   5.1.2.1 FIELD OF APPLICATION

   The field of application of API MPMS Chapter 5 is the measurement of liquid hydrocarbons and chemicals by meter, at the temperature and pressure conditions that prevail inside a meter during flowing conditions. API MPMS Chapter 5 is also concerned with the metering of hydrocarbons that can,

   1

   by heating, cooling, and/or compressing, be made and kept liquid by maintaining the proper temperature and pressure.

   The chapter does not apply to the metering of two-phase fluids.

   
   

3. Referenced Publications

   As stated in the foreword, this edition of API MPMS Chap- ter 5 contains six main sections; others may be added if the need arises. The current editions of the following API MPMS Standards contain information applicable to this chapter:

   API Manual of Petroleum Measurement Standards

   Chapter 1 “Vocabulary” Chapter 4 “Proving Systems”

   Chapter 6 “Metering Assemblies” Chapter 7 “Temperature”

   Chapter 8 “Sampling”

   Chapter 9 “Density”

   Chapter 11 “Physical Properties Data”

   Chapter 12 “Statistical Aspects of Measuring and Sampling”

   Chapter 13 “Application of Statistical Methods” Chapter 14 “Natural Gas Fluids Measurement” Chapter 20.1 “Allocation Measurement”

   Chapter 21.2 “Flow Measurement Using Electronic Metering Systems”

   
   

4. Considerations for the Design of Meter Installations

The design of meter installations should take into account the following considerations:

1. The installation should be capable of satisfying the required performance characteristics for the application between the maximum and minimum flow rates, at the maxi- mum operating pressure, and over the temperature range and liquid types to be measured. If necessary, the installation should include protective devices that keep the operation of the meter within design limits.

2. The installation should ensure a maximum, dependable operating life. Strainers, filters, air/vapor eliminators, or other protective devices may be provided upstream of the meter to remove solids and/or gases that could cause meter damage, premature meter wear and/or measurement error.

3. The installation should maintain adequate pressure on the liquid in the metering system at all temperatures to ensure