GB23971-2025
Organic heat transfer fluids
有机热载体
GB 23971-2025 is an upcoming mandatory Chinese national standard for Organic heat transfer fluids. It appears in the Chemicals compliance cluster with a energy efficiency focus and has an implementation date of Nov 1, 2026.
Applicability depends on product scope, certification route, competent authority notices and transition rules. Requst for the translation or verify source before using this record in a compliance decision.
Compliance overview
Scope and applicability
This standard specifies the classification, marking, requirements, and testing methods for unused organic heat transfer fluids used in various types of indirect heat transfer systems. It applies to both mineral oil type and synthetic type organic heat transfer fluids. This standard is mandatory for manufacturers of organic heat transfer fluids in China. It does not apply to fluids directly used for heating or cooling oxidizing chemicals, nor to fluids produced from reclaimed oil. Additionally, products classified as L-QA according to GB/T 7631.12 are excluded.
Technical requirements
The standard outlines the physical and chemical requirements for organic heat transfer fluids, categorized into L-QB, L-QC, and L-QD types based on their maximum permitted bulk temperature. Key parameters include auto-ignition point, flash point (closed and open cup), sulfur content, and chlorine content. Manufacturers must ensure that the maximum working temperature is at least 10°C lower than the maximum permitted bulk temperature. The standard also specifies limits for acid value, copper strip corrosion, and water content to ensure system safety and fluid longevity. For fluids used in the food or pharmaceutical industries, additional national safety regulations apply. Animal and vegetable oils or their processed products must not be used as organic heat transfer fluids. The standard also defines requirements for thermal stability and thermal oxidation stability, which are critical for high-temperature operations. Viscosity, density, and distillation range are required to be reported by the manufacturer to assist users in system design.
Testing methods
The standard references various testing methods to verify compliance. Auto-ignition point is tested according to GB/T 21860, while flash point uses GB/T 261 and GB/T 3536. Thermal stability is evaluated using GB/T 23800, which measures the deterioration rate at the maximum permitted temperature. Specific testing for total chlorine content is conducted using the microcoulometric method detailed in Annex A. Thermal oxidation stability is assessed via the method in Annex B, involving heating with a steel rod catalyst for at least 72 hours.
FAQs
What products are regulated under GB 23971-2025?
GB 23971-2025 regulates unused organic heat transfer fluids, including both mineral oil type and synthetic type fluids used in indirect heat transfer systems.
Are there any updates from the previous version of GB 23971?
Yes, the 2025 version replaces GB 23971-2009. Key updates include the addition of regulations for fluids used in the food or pharmaceutical industries, a change in the sulfur content limit to ≤500 mg/kg, and updated testing methods for auto-ignition point and kinematic viscosity.
Does GB 23971-2025 apply to reclaimed oil products?
No, this standard explicitly excludes organic heat transfer fluids produced from reclaimed or recycled oil. It only applies to unused fluids.
The summary above provides a high-level overview of GB 23971-2025. To ensure complete compliance for your products entering the Chinese market, a precise and professional translation of the full technical specifications is essential. Purchase our high-quality English translation of GB 23971-2025 today to access all detailed parameters, tables, and testing procedures.
Applicability hints
- Type
- Product
- CCS
- E 34
- ICS
- 75.100
- Competent department
- National Energy Administration
- Technical committee
- National Technical Committee on Petroleum Products and Lubricants of Standardization Administration of China
Relationships
Replaces:GB 23971-2009 (Current)