1. Q: What is the main material used for fire protection steel pipe?
A: Fire protection steel pipe is typically made of galvanized carbon steel (such as Q235B), coated with zinc for enhanced corrosion resistance. High-pressure systems may use seamless steel pipe (such as 20# steel).
For example, indoor fire hydrant systems often use DN65-DN150 galvanized welded steel pipe, while high-pressure spray systems may use SCH40 seamless steel pipe.
2. Q: What are the connection methods for fire protection steel pipe?
A: Common methods include:
Threaded connection (galvanized pipe DN ≤ 80mm, such as fire hydrant branch pipes);
Flange connection (large-diameter pipes or locations requiring frequent disassembly, such as pump inlets and outlets);
Groove connection (clamp) (pipe DN ≥ 100mm, quick installation, such as shopping mall fire main pipes).
For example, a high-rise building's fire riser uses a groove connection to prevent welding from damaging the galvanized coating.
3. Q: What anti-corrosion treatments are required for fire protection steel pipe?
A:
Galvanizing: Conventional corrosion protection, suitable for humid environments (such as basements);
Epoxy resin coating: Chemical resistance, used in chemical plants;
External wall coating: Buried pipes require 3PE corrosion protection (such as outdoor fire protection pipe networks).
For example, the fire protection pipes in a chemical plant are protected with a double layer of galvanizing and epoxy resin.
4. Q: How is the design pressure of fire protection steel pipes determined?
A: It depends on the system type:
Fire hydrant systems are typically 1.0-1.6 MPa;
Sprinkler systems have high-pressure areas exceeding 2.5 MPa.
For example, the steel pipe design pressure for a high-pressure water mist system in a data center is 3.0 MPa, and SCH80 seamless steel pipe is used.
5. Q: What are the acceptance criteria for fire protection steel pipes?
A: The following standards must be met:
GB/T 3091-2015 (Galvanized welded steel pipes for low-pressure fluid transportation);
GB 50974-2014 (Technical specification for fire-fighting water supply and fire hydrant systems);
Hydraulic pressure test: 1.5 times the working pressure, maintained for 30 minutes with no leakage.
