Vietnam: What are the technical requirements for fire hydrants under National Standard TCVN 6379: 1998? What is the definition of fire hydrant?
- What is the definition of fire hydrant in Vietnam specified in National Standard TCVN 6379: 1998?
- What are the technical requirements for fire hydrants in Vietnam under National Standard TCVN 6379: 1998?
- What are the regulations on labeling, packaging, transportation, and storage of fire hydrants in Vietnam?
What is the definition of fire hydrant in Vietnam specified in National Standard TCVN 6379: 1998?
Regarding National Standard TCVN 6379: 1998, this National Standard applies to all fire hydrants (fire hydrants installed in common water supply systems such as urban water supply, and external water supply of houses or buildings).
Accordingly, fire hydrants are defined as specialized equipment installed into the water supply pipeline system used to collect water for firefighting. The fire hydrant consists of the main parts such as valves, hydrant bodies, and waiting throats of standard size.
Fire hydrants are divided into two types: floating fire hydrants (floating hydrants) and underground fire hydrants (underground hydrants).
What are the technical requirements for fire hydrants in Vietnam under National Standard TCVN 6379: 1998?
Pursuant to Section 5 of National Standard TCVN 6379: 1998 as follows:
TECHNICAL REQUIREMENTS:
5.1. Fire hydrants must be manufactured in accordance with this standard. When fabricating fire hydrants of similar and other special textures and dimensions, approval from the fire protection agency must be obtained.
5.2. Fire hydrants must withstand a test pressure of not less than 1.5Mpa. When tested according to 6.10, do not allow the Fire hydrant to show signs of cracking or residual deformation.
5.3. After assembling the fire hydrant, it must ensure:
Sealed with hydraulic pressure not less than 1Mpa;
The swing torque for opening and closing the fire hydrant valve when the water pressure is not less than 1Mpa must be not greater than 150Nm. When tested according to 6.11 in a closed valve state, no leakage, or "sweating" is allowed at the joints and on the hydrant body.
5.4. The fire hydrant valve and valve drive mechanism shall withstand an axial load not less than 3.104N. When tested according to 6.13, do not allow the valve to break, thread failure, or latch failure.
5.5. The amount of water stagnant in the fire hydrant must not be greater than 50 cm3. When the amount of standing water is larger, the consent of the competent authority must be obtained.
5.6. The diameter of the standing water discharge hole of the hydrant body is not less than 8mm, at the outlet of the stagnant water discharge hole is the cylindrical pipe "Cell 1/2" according to TCVN 4681: 1989.
5.7. The outer thread of the coupling with the water intake column of the underground hydrant is a cylindrical pipe thread "Box 6" with a tolerance of 8g according to TCVN 1917: 1993.
5.8. The waiting throat of the floating hydrant must be suitable for connector type DR.2-125 (M150x6) for large throat and connector type DT.1-77 for small throat according to TCVN 5739: 1993.
5.9. Valve shaft thread is trapezoidal thread according to TCVN 209: 1996; TCVN 210:1966: TCVN 2254:1977.
5.10. The threaded joint between the valve blade and the valve body is 7H/8g according to TCVN 1917: 1993.
5.11. The body and valve of the Fire hydrant shall be made of materials with mechanical properties and corrosion resistance not lower than gray cast iron GX 15-32.
5.12. The valve shaft of the threaded part of the Fire hydrant shall be made of stainless steel with mechanical and physical properties not lower than steel 30 Cr 13.
5.13. The threaded part of the screw joint of the underground hydrant shall be made of materials with mechanical properties and corrosion resistance not lower than Cu5Sn5Zn5Pb copper alloy or CuZn4Si brass.
The structure and way of fixing the valve shaft of the Fire hydrant must ensure the strength and reliability of the coupling, and there must be no possibility of the coupling being rotated when unlocking the hydrant to take fire water.
5.14. The valve sealing ring must be made of heat-resistant, cold-resistant, wear-resistant, high-hardness rubber, and resistant to corrosive environments according to TCVN 2003-77. It is permissible to use other types of materials with equivalent properties.
5.15. Error in size and mass of castings from gray cast iron – accuracy level 3 according to TCVN 385-70.
5.16. The details of the valve, the part connected to the shaft must be made of materials with basic properties no less than copper alloy grade Cu5Sn5Zn5Pb or brass grade CuZn4Si.
5.17. The paint layer on the surface outside the water hydrant must not peel, under prescribed operating conditions. The floating hydrant must be painted orange or yellow in the entire valve shaft protection cover at the top of the hydrant.
5.18. The square part of the shaft for connecting the underground hydrant to the fire water intake column has a size of 22x22mm with a square part size accuracy of -0.5. The surface of the square section has a hardness of 26 to 38 HRC.
5.19. The cover of the underground hydrant must be of the flip type, without obstructing the installation of the water intake column. The cover of the water throat and valve shaft of the floating hydrant must open with the Z22 5-side key.
Thus, fire hydrants in Vietnam must meet the basic technical requirements mentioned above.
What are the regulations on labeling, packaging, transportation, and storage of fire hydrants in Vietnam?
Pursuant to Section 7 of National Standard TCVN 6379: 1998, the regulations on labeling, packaging, transportation, and storage of fire hydrants in Vietnam include:
- The following contents must be clearly and fully stated on each fire hydrant:
+ Name or sign of goods of the manufacturer;
+ Type of fire hydrant;
+ Year of manufacture;
+ This National Standard number;
The label is affixed at the rear of the large throat for the floating hydrant and on the lower body for the underground hydrant.
- Open threads and surfaces of unpainted metal parts must be greased and preserved.
- Each fire hydrant must be accompanied by instructions for installation and operation as prescribed in Appendices A and B promulgated together with TCVN 6379: 1998.
- Fire hydrants must be stored in dry places. The valve must be closed when storing and transporting the fire hydrant.
- When transporting, fire hydrants must be separately packed and securely fixed. If the fire hydrant is packaged in bales, each bale must not exceed 6 pieces for floating hydrants and 10 pieces for underground hydrants.
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