ISO 7876-5:2021

Fuel injection equipment - Vocabulary - Part 5: Common rail fuel injection system

This document establishes a vocabulary for common rail (CR) fuel injection systems for diesel (compression-ignition) engines and their components. The terms defined in this document are unique to common rail fuel injection systems, terms and definitions relating to other fuel injection systems are found in the other parts of the ISO 7876 series.

Équipement d'injection de combustible — Vocabulaire — Partie 5: Système d'injection de combustible à rampe commune

General Information

• Status: Published
• Publication Date: 09-Dec-2021
• ICS: 01.040.43 - Road vehicle engineering (Vocabularies)
• ICS: 43.060.40 - Fuel systems
• Technical Committee: ISO/TC 22/SC 34 - Propulsion, powertrain and powertrain fluids
• Drafting Committee: ISO/TC 22/SC 34/WG 2 - Injection equipment
• Current Stage: 6060 - International Standard published
• Start Date: 10-Dec-2021
• Due Date: 20-May-2022
• Completion Date: 10-Dec-2021

Relations

• Revises: ISO 7876-5:2004 - Fuel injection equipment - Vocabulary - Part 5: Common rail fuel injection system
• Effective Date: 17-Jul-2021

Overview

ISO 7876-5:2021 - Fuel injection equipment - Vocabulary - Part 5: Common rail fuel injection system - is the ISO international vocabulary for common rail (CR) fuel injection systems used on diesel (compression‑ignition) engines. This second edition (2021) updates and extends the terminology used worldwide to describe CR components, functions and injection strategies. The standard is descriptive (no normative references) and is part of the wider ISO 7876 series covering fuel injection equipment.

Key topics and defined terms

This document establishes precise definitions for terms unique to common rail systems, enabling consistent communication across design, testing and regulatory contexts. Important entries and technical topics include:

• Common rail fuel injection system (CRS) - defined by a high‑pressure supply pump, a rail or distribution block, and CR injectors; rail pressure is electronically controlled and independent of engine speed/load.
• CR injector - an injector with an electrical valve (solenoid or piezo) to control start/end of injection; may include a pressure amplifier.
• High‑ and low‑pressure supply components:
  • fuel feed pump (low‑pressure)
  • high‑pressure supply pump
  • internal transfer pump
• Pressure and flow control devices:
  • pressure control valve (electrically actuated spill valve)
  • inlet control valve and outlet control valve
  • pressure limiter (safety valve)
  • CR pressure sensor
• Rail and distribution:
  • rail (long tube‑type high‑pressure chamber) and distribution block (non‑long shaped high‑pressure chamber)
  • flow limiter and flow damper
• Injection strategies:
  • multiple injection, pre (pilot) injection, main injection, post (after) injection

The Introduction notes that terms have been added to reflect updated CR functionality aimed at improved engine performance, emissions control, fuel economy and NVH.

Applications and users

ISO 7876-5:2021 is practical for organizations and professionals who need unambiguous, standardized terminology for common rail systems, including:

• Engine and powertrain designers and calibration engineers
• OEMs and component suppliers (injectors, rails, pumps, sensors, valves)
• Test laboratories and validation teams
• Technical writers, translators and documentation teams
• Regulatory bodies, certification authorities and procurement specialists
• Training providers and maintenance/repair organizations

Using the standardized vocabulary reduces misinterpretation in specifications, design reviews, service manuals and regulatory submissions.

Related standards

• ISO 7876 series - other parts for different fuel injection systems (see ISO website for the full list)
• ISO 7876-2 - Fuel injectors vocabulary
• ISO 2710 (all parts) - Reciprocating internal combustion engines - Vocabulary

Keywords: ISO 7876-5:2021, common rail, CRS, CR injector, fuel injection equipment, diesel engines, vocabulary, fuel system terminology.

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 7876-5
Second edition
2021-12
Fuel injection equipment —
Vocabulary —
Part 5:
Common rail fuel injection system
Équipement d'injection de combustible — Vocabulaire —
Partie 5: Système d'injection de combustible à rampe commune
Reference number
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
Bibliography . 4
iii
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 34,
Propulsion, powertrain, and powertrain fluids.
This second edition cancels and replaces the first edition (ISO 7876-5:2004), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— additional terms, already in use worldwide, have been added to Clause 3.
A list of all parts in the ISO 7876 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
Introduction
Since this document was published in 2004, the common rail fuel injection system has updated its
functions or component performances to improve diesel engine performance and exhaust after
treatment with respect to driveability, engine power, emission, fuel consumption, noise, vibration and
so on. New terms are defined to describe this updated functionality.
v
INTERNATIONAL STANDARD ISO 7876-5:2021(E)
Fuel injection equipment — Vocabulary —
Part 5:
Common rail fuel injection system
1 Scope
This document establishes a vocabulary for common rail (CR) fuel injection systems for diesel
(compression-ignition) engines and their components. The terms defined in this document are unique
to common rail fuel injection systems, terms and definitions relating to other fuel injection systems are
found in the other parts of the ISO 7876 series.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
ISO and IEC maintain terminological databases for use in standardization at
...