1 General provisions
1.0.1 This specification is formulated in order to reasonably design the heptafluoropropane foam extinguishing system, thus ensuring its construction quality and use function, reducing fire hazards and protecting personal and property safety.
1.0.2 This specification is applicable to the heptafluoropropane foam extinguishing system installed in vertical flammable liquid storage tanks.
1.0.3 In addition to this specification, the design, construction, acceptance, maintenance and management of heptafluoropropane foam extinguishing system shall also meet the requirements of current relevant national standards.
2 Terms and symbols
2.1 Terms
2.1.1 heptafluoropropane foam extinguishing system
extinguishing system which is composed of water supply system, foam concentrate storage tank, heptafluoropropane storage device and its starting device, foam proportioning set, heptafluoropropane proportioning set, heptafluoropropane foam maker, valve, pipeline, etc. and which is able to produce heptafluoropropane foam
2.1.2 heptafluoropropane proportioning set
set for mixing liquid heptafluoropropane and foam solution at a specified concentration
2.1.3 heptafluoropropane foam solution
solution prepared from liquid heptafluoropropane and foam solution at a specific ratio
2.1.4 heptafluoropropane concentration
volume percentage of liquid heptafluoropropane in heptafluoropropane foam solution
2.1.5 heptafluoropropane foam maker
device for foaming and producing heptafluoropropane foam by gasification of liquid heptafluoropropane in heptafluoropropane foam solution
2.2 Symbols
C——heptafluoropropane concentration;
K——margin coefficient;
k——flow characteristic coefficient of heptafluoropropane foam maker;
Nc——quantity of heptafluoropropane storage vessels required for the system;
P——inlet pressure of heptafluoropropane foam maker;
Pc——storage pressure of heptafluoropropane storage vessel;
Pcs——residual pressure of heptafluoropropane storage vessel;
q——flow of heptafluoropropane foam solution for heptafluoropropane foam maker;
Vc——volume of a single heptafluoropropane storage vessel;
Vcs——residual amount of liquid heptafluoropropane in a single storage vessel;
Vjs——residual amount of liquid in the header pipe of heptafluoropropane storage device;
Vq——design consumption of liquid heptafluoropropane;
V0——design consumption of heptafluoropropane foam solution.
3 Extinguishing agent and system components
3.1 Selection and storage of extinguishing agent
3.1.1 For the foam concentrate, the extinguishing performance shall be of Grade I or Grade AR I, and the burn resistance shall be of Grade A.
3.1.2 When extinguishing water-soluble liquid fire or using a system to protect water-soluble and water-insoluble liquid storage tanks at the same time, anti-soluble foam concentrate must be selected.
3.1.3 The heptafluoropropane extinguishing agent shall comply with the current national standard GB 18614 Fire extinguishing agent heptafluoropropane (HFC227ea).
3.1.4 The heptafluoropropane concentration shall not be less than 5%.
3.1.5 The heptafluoropropane storage device should be set in a ventilated and dry room at 0~50℃, and the distance between the wall and the protected storage tank shall not be less than 30m.
Foreword i
1 General provisions
2 Terms and symbols
2.1 Terms
2.2 Symbols
3 Extinguishing agent and system components
3.1 Selection and storage of extinguishing agent
3.2 System components
4 Design
5 Construction
5.1 General requirements
5.2 Admission inspection
5.3 Installation
5.4 Commissioning
6 Acceptance
7 Maintenance and management
Annex A Division of section works, sub-section works and sub-item works
Annex B Records on system construction and acceptance
Annex C Records on system maintenance and management
Explanation of wording in this specification
List of quoted standards
