GB/T 18442.6-2019Static vacuum insulated cryogenic pressure vessels—Part 6: Safety protection (English PDF)

Foreword

GB/T 18442 "Static vacuum insulated cryogenic pressure vessel" is divided into the following 7 parts.

- Part 1: Rules;

- Part 2: Materials;

- Part 3: Design;

- Part 4: Fabrication;

- Part 5: Inspection and test;

- Part 6: Safety device requirements;

- Part 7: Rules of pressure strengthening for inner vessels.

This part is Part 6 of GB/T 18442.

This part was drafted in accordance with the rules given in GB/T 1.1-2009.

This part replaces GB/T 18442.6-2011 "Static vacuum insulated cryogenic pressure vessel - Part 6: Safety device requirements". Compared with GB/T 18442.6-2011, the main technical changes except for editorial changes are as follows:

- MODIFY the general requirements; ADD the explosion-proof requirements of electrical control components, as well as the connection requirements of safety valves, instruments and handling accessories and pipelines;

- MODIFY the setting requirements of the overpressure relief device of the inner vessel; MODIFY the schematic diagram of the typical setting of the overpressure relief device;

- MODIFY the design requirements of overpressure relief devices;

- ADD the installation requirements of the overpressure relief device of the inner vessel, the type of the explosion-proof device of the outer casing, the requirements of the installation location;

- MODIFY the requirements for the setting of the emergency shut-off valve, the grounding resistance value of the static conductive grounding device, the requirements for the liquid level measuring device and the pressure measuring device, the requirements for handling accessories;

- ADD the relevant requirements for temperature measuring devices, vacuum measuring devices, measuring devices with sensors or electrical control elements;

- DELETE handling hoses and related requirements;

- In Appendix A, ADD the provisions for the calculation method of the safe discharge volume of tanks storing non-flammable and explosive media; MODIFY the formula (A.5).

The calculation of the safe discharge volume of the tank body and the discharge capacity of the overpressure relief device in this part refers to ISO 21013-3:2016 "Cryogenic vessels - Pressure-relief accessories for cryogenic service - Part 3. Sizing and capacity determination".

1 Scope

This part of GB/T 18442 specifies the selection principles and setting requirements of safety accessories, gauges, handling accessories used in static vacuum insulated cryogenic pressure vessels (hereinafter referred to as "cryogenic vessels"), as well as the calculation of the safety discharge volume of tank, the calculation of the discharge capacity of the overpressure relief device.

This part applies to cryogenic vessels that meet the following conditions at the same time.

a) The working pressure of the inner vessel is not less than 0.1 MPa;

b) The geometric volume is not less than 1 m³;

c) The insulation method is vacuum powder insulation, vacuum composite insulation or high vacuum multilayer insulation;

d) The storage medium is a refrigerated liquefied gas with a standard boiling point not lower than -196 °C.

This part does not apply to cryogenic vessels in the following ranges.

a) The inner vessel and outer shell materials are non-ferrous or non-metallic;

b) Spherical structure;

c) Stacked and insulated;

d) Mobile;

e) Store frozen liquefied gas medium with standard boiling point lower than -196 °C;

f) The storage medium is a toxic gas according to GB 12268;

g) Special requirements for national defense and military equipment.

2 Normative references

The following documents are essential to the application of this document. For the dated documents, only the versions with the dates indicated are applicable to this document; for the undated documents, only the latest version (including all the amendments) are applicable to this standard.

GB/T 150 (all parts) Pressure vessel

GB/T 567.1 Bursting disc safety device - Part 1: Basic requirements

GB/T 567.2 Bursting disc safety device - Part 2: Application, selection and installation

GB/T 567.3 Bursting disc safety device - Part 3: Classification and installation dimensions

GB/T 567.4 Bursting disc safety device - Part 4: Type test

GB/T 18442.1 Stationary vacuum thermal-insulating cryogenic pressure vessel - Part 1: Rule

GB/T 18442.3 Stationary vacuum thermal-insulating cryogenic pressure vessel - Part 3: Design

GB/T 18442.5 Stationary vacuum thermal-insulating cryogenic pressure vessel - Part 5: Inspection and test

3 Terms and definitions

The terms and definitions as defined in GB/T 150, GB/T 18442.1, GB/T 18442.3, GB/T 18442.5 apply to this document.

4 Safety accessories, instruments and handling accessories

4.4.1.4 The device equipped with a remote-control interface to facilitate the closing operation of the remote-control system shall be set in a location that is easy for personnel to reach in the engineering system.

4.4.1.5 The connection between the emergency shut-off valve and the liquid phase port, gas phase port, and booster port of the tank can be flanged or welded.

4.10.2 The measuring range and accuracy level of the measuring device shall meet the requirements of the design documents.

4.10.3 The installation structure of the measuring device shall be firm and reliable; its connecting wires and conduits shall not interfere with adjacent parts.