ISO 11366:2025

Petroleum and related products - In-servicing of steam, gas and combined cycle turbines lubricating oils - Guidance and requirements

This document provides guidance and requirements for the maintenance in service of mineral oils used as lubricating oils and control fluids used to lubricate steam, gas and combined cycle turbines in service.

This document is applicable to lubricants classified in ISO 6743-5 and specified in ISO 8068, except the grades TSD, TGD and TCD (phosphate esters) for which ISO 11365 is more relevant, and the grades TGCE, THA, THCH, THCE and THE.

This document also gives guidance and requirements with respect to the corrective actions that are taken to maximize service life.

To comply with a standard, you need to quickly understand its issues in order to determine its impact on your activity.

The Requirements department helps you quickly locate within the normative text:
- mandatory clauses to satisfy,
- non-essential but useful clauses to know, such as permissions and recommendations.

The identification of these types of clauses is based on the document “ISO / IEC Directives, Part 2 - Principles and rules of structure and drafting of ISO documents ”as well as on a constantly enriched list of verbal forms.

With Requirements, quickly access the main part of the normative text!

The Redline + service - standards comparator allows you to easily and simply identify major changes between the current standard and its last canceled version.

At a glance, you will be able to identify the additions, deletions or modifications to a text, table, figure and formula.


The Redlines + service is offered to you on the collection of French standards in force, in French language and in HTML and PDF format.

For an overview of the service, click on View a standard in redline format

COBAZ is the simple and effective solution to meet the normative needs related to your activity, in France and abroad.

Available by subscription, CObaz is THE modular solution to compose according to your needs today and tomorrow. Quickly discover CObaz!

Request your free, no-obligation live demo

I discover COBAZ