GB/T 33215-2025 Pressure relief devices for gas cylinders English, Anglais, Englisch, Inglés, えいご
This is a draft translation for reference among interesting stakeholders. The finalized translation (passing through draft translation, self-check, revision and verification) will be delivered upon being ordered.
ICS 97.200.01
CCS H 57
National Standard of the People's Republic of China
GB/T 33215-2025
Replaces GB/T 33215-2016
Pressure relief devices for gas eylinders
Issue date: 2025-08-29 Implementation date: 2026-03-01
Issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
the Standardization Administration of the People's Republic of China
Contents
Foreword
1 Scope
2 Normative References
3 Terms, Definitions, and Symbols
4 Types and Structural Forms of Pressure Relief Devices
5 Installation Requirements for Pressure Relief Devices
6 Selection Requirements for Pressure Relief Devices
7 Basic Requirements for Pressure Relief Devices
8 Safety Venting Capacity and Rated Discharge of Pressure Relief Devices
9 Determination Requirements for Set Pressure and Set Temperature of Pressure Relief Devices
10 Marking, Installation, and Maintenance of Pressure Relief Devices
Appendix A (Informative) Compressibility Factor of Gases
References
Safety Pressure Relief Devices for Gas Cylinders
1 Scope
This document specifies the types, structural forms, installation requirements, selection criteria, basic requirements, calculation methods for safety venting capacity and rated discharge, determination requirements for set pressure or set temperature, as well as marking, installation, and maintenance of safety pressure relief devices for gas cylinders.
This document applies to gas cylinders of various structural types and containing various gases.
2 Normative References
The following referenced documents contain provisions that are essential to this document through normative citations. For dated references, only the version cited applies; for undated references, the latest version (including any amendments) applies.
GB/T 8337 Fusible Alloy Plug Devices for Gas Cylinders
GB/T 13005 Terminology for Gas Cylinders
GB/T 16918 Bursting Disc Safety Devices for Gas Cylinders
GB/T 17268 Non-refillable Welded Steel Cylinders for Industrial Use
GB 18428 Glass Bulbs for Automatic Fire Extinguishing Systems
GB/T 42536 Combination Valves for High-Pressure Hydrogen Storage Cylinders in Vehicles
3 Terms, Definitions, and Symbols
3.1 Terms and Definitions
Terms and definitions as defined in GB/T 13005 and the following apply to this document.
3.1.1
Pressure relief device
A pressure release device installed on a gas cylinder to rapidly and automatically vent gas under accidental high-temperature conditions, preventing cylinder rupture.
Note: Includes temperature-activated or pressure-activated relief devices.
3.1.2
Safety venting capacity
The minimum gas flow rate required to prevent further pressure increase in a gas cylinder after reaching its allowable pressure under accidental high-temperature conditions.
3.1.3
Rated capacity
The mass of gas discharged per unit time by a pressure relief device under specified venting conditions.
3.1.4
Thermally activated pressure relief device (TPRD)
A temperature-activated pressure relief device.
Note: Includes fusible alloy plug devices, fusible alloy-driven devices, and glass bulb-driven devices.
3.1.5
Vent area (A)
The minimum geometric flow cross-sectional area of a pressure relief device for discharging the medium.
3.2 Symbols
The following symbols apply to this document:
A – Vent area of the pressure relief device, in square millimeters (mm²).
A₀ – External surface area of the gas cylinder, in square meters (m²).
C – Gas characteristic coefficient.
K – Discharge coefficient of the pressure relief device.
k – Adiabatic index of the gas.
M – Molar mass of the medium in the cylinder, in kilograms per kilomole (kg/kmol).
P – Relief pressure (absolute), in megapascals (MPa).
Note: For bursting disc devices, it is the design burst pressure; for TPRDs, it is the saturated vapor pressure of the medium at the set temperature (for liquefied gases) or the ideal gas pressure at the set temperature (for compressed gases); for safety valves, it is the rated relief pressure.
Pc – Critical pressure (absolute), in megapascals (MPa).
q – Latent heat of vaporization of the medium in the cylinder at the relief pressure, in kilojoules per kilogram (kJ/kg).
T – Temperature of the medium at the relief pressure (absolute), in kelvins (K).
Tc – Critical temperature (absolute), in kelvins (K).
V – Nominal water capacity of the gas cylinder, in liters (L).
Wr – Rated discharge capacity of the pressure relief device, in kilograms per hour (kg/h).
Ws – Safety venting capacity of the gas cylinder, in kilograms per hour (kg/h).
Z – Compressibility factor of the gas at absolute pressure (P) and absolute temperature (T).
4 Types and Structural Forms of Safety Pressure Relief Devices
4.1 Fusible Alloy Plug Device
Composed of a fusible alloy and a plug seat, directly connected to the cylinder body or valve. When the temperature reaches a predetermined value, the fusible alloy melts, directly venting the gas. Fusible alloy plug devices shall comply with GB/T 8337.
4.2 Fusible Alloy Actuated Device
Composed of a fusible alloy and an actuator, connected to the valve body. When the temperature reaches a predetermined value, the fusible alloy melts, causing the actuator to open and vent the gas.
4.3 Glass Bulb Actuated Device
Composed of a glass bulb (or glass sphere), a support, and an actuator, connected to the valve body. When the temperature reaches a predetermined value, the glass bulb shatters, causing the actuator to open and vent the gas.
4.4 Bursting Disc Device
Composed of a bursting disc, a retainer ring, and fasteners (for non-refillable welded cylinders, the disc may be directly welded to the cylinder opening). When the internal pressure reaches a predetermined value, the disc ruptures, venting the gas. Bursting disc devices shall comply with GB/T 16918.
4.5 Safety Valve
A pressure-controlled, reusable device consisting of a valve seat, disc, and spring. When the internal pressure reaches a predetermined value, the disc lifts off the seat, venting the gas. The disc recloses when the pressure drops below the set value.
4.6 Bursting Disc-Fusible Alloy Plug Composite Device
Standard
GB/T 33215-2025 Pressure relief devices for gas cylinders (English Version)
GB/T 33215-2025 Pressure relief devices for gas cylinders English, Anglais, Englisch, Inglés, えいご
This is a draft translation for reference among interesting stakeholders. The finalized translation (passing through draft translation, self-check, revision and verification) will be delivered upon being ordered.
ICS 97.200.01
CCS H 57
National Standard of the People's Republic of China
GB/T 33215-2025
Replaces GB/T 33215-2016
Pressure relief devices for gas eylinders
Issue date: 2025-08-29 Implementation date: 2026-03-01
Issued by the General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China
the Standardization Administration of the People's Republic of China
Contents
Foreword
1 Scope
2 Normative References
3 Terms, Definitions, and Symbols
4 Types and Structural Forms of Pressure Relief Devices
5 Installation Requirements for Pressure Relief Devices
6 Selection Requirements for Pressure Relief Devices
7 Basic Requirements for Pressure Relief Devices
8 Safety Venting Capacity and Rated Discharge of Pressure Relief Devices
9 Determination Requirements for Set Pressure and Set Temperature of Pressure Relief Devices
10 Marking, Installation, and Maintenance of Pressure Relief Devices
Appendix A (Informative) Compressibility Factor of Gases
References
Safety Pressure Relief Devices for Gas Cylinders
1 Scope
This document specifies the types, structural forms, installation requirements, selection criteria, basic requirements, calculation methods for safety venting capacity and rated discharge, determination requirements for set pressure or set temperature, as well as marking, installation, and maintenance of safety pressure relief devices for gas cylinders.
This document applies to gas cylinders of various structural types and containing various gases.
2 Normative References
The following referenced documents contain provisions that are essential to this document through normative citations. For dated references, only the version cited applies; for undated references, the latest version (including any amendments) applies.
GB/T 8337 Fusible Alloy Plug Devices for Gas Cylinders
GB/T 13005 Terminology for Gas Cylinders
GB/T 16918 Bursting Disc Safety Devices for Gas Cylinders
GB/T 17268 Non-refillable Welded Steel Cylinders for Industrial Use
GB 18428 Glass Bulbs for Automatic Fire Extinguishing Systems
GB/T 42536 Combination Valves for High-Pressure Hydrogen Storage Cylinders in Vehicles
3 Terms, Definitions, and Symbols
3.1 Terms and Definitions
Terms and definitions as defined in GB/T 13005 and the following apply to this document.
3.1.1
Pressure relief device
A pressure release device installed on a gas cylinder to rapidly and automatically vent gas under accidental high-temperature conditions, preventing cylinder rupture.
Note: Includes temperature-activated or pressure-activated relief devices.
3.1.2
Safety venting capacity
The minimum gas flow rate required to prevent further pressure increase in a gas cylinder after reaching its allowable pressure under accidental high-temperature conditions.
3.1.3
Rated capacity
The mass of gas discharged per unit time by a pressure relief device under specified venting conditions.
3.1.4
Thermally activated pressure relief device (TPRD)
A temperature-activated pressure relief device.
Note: Includes fusible alloy plug devices, fusible alloy-driven devices, and glass bulb-driven devices.
3.1.5
Vent area (A)
The minimum geometric flow cross-sectional area of a pressure relief device for discharging the medium.
3.2 Symbols
The following symbols apply to this document:
A – Vent area of the pressure relief device, in square millimeters (mm²).
A₀ – External surface area of the gas cylinder, in square meters (m²).
C – Gas characteristic coefficient.
K – Discharge coefficient of the pressure relief device.
k – Adiabatic index of the gas.
M – Molar mass of the medium in the cylinder, in kilograms per kilomole (kg/kmol).
P – Relief pressure (absolute), in megapascals (MPa).
Note: For bursting disc devices, it is the design burst pressure; for TPRDs, it is the saturated vapor pressure of the medium at the set temperature (for liquefied gases) or the ideal gas pressure at the set temperature (for compressed gases); for safety valves, it is the rated relief pressure.
Pc – Critical pressure (absolute), in megapascals (MPa).
q – Latent heat of vaporization of the medium in the cylinder at the relief pressure, in kilojoules per kilogram (kJ/kg).
T – Temperature of the medium at the relief pressure (absolute), in kelvins (K).
Tc – Critical temperature (absolute), in kelvins (K).
V – Nominal water capacity of the gas cylinder, in liters (L).
Wr – Rated discharge capacity of the pressure relief device, in kilograms per hour (kg/h).
Ws – Safety venting capacity of the gas cylinder, in kilograms per hour (kg/h).
Z – Compressibility factor of the gas at absolute pressure (P) and absolute temperature (T).
4 Types and Structural Forms of Safety Pressure Relief Devices
4.1 Fusible Alloy Plug Device
Composed of a fusible alloy and a plug seat, directly connected to the cylinder body or valve. When the temperature reaches a predetermined value, the fusible alloy melts, directly venting the gas. Fusible alloy plug devices shall comply with GB/T 8337.
4.2 Fusible Alloy Actuated Device
Composed of a fusible alloy and an actuator, connected to the valve body. When the temperature reaches a predetermined value, the fusible alloy melts, causing the actuator to open and vent the gas.
4.3 Glass Bulb Actuated Device
Composed of a glass bulb (or glass sphere), a support, and an actuator, connected to the valve body. When the temperature reaches a predetermined value, the glass bulb shatters, causing the actuator to open and vent the gas.
4.4 Bursting Disc Device
Composed of a bursting disc, a retainer ring, and fasteners (for non-refillable welded cylinders, the disc may be directly welded to the cylinder opening). When the internal pressure reaches a predetermined value, the disc ruptures, venting the gas. Bursting disc devices shall comply with GB/T 16918.
4.5 Safety Valve
A pressure-controlled, reusable device consisting of a valve seat, disc, and spring. When the internal pressure reaches a predetermined value, the disc lifts off the seat, venting the gas. The disc recloses when the pressure drops below the set value.
4.6 Bursting Disc-Fusible Alloy Plug Composite Device
