Clauses for Using Knife Gate Valves for Pulverized Fuel Application
Knife Gate Valves for Pulverized Fuel application
Standards applicable:NFPA 8503 – Standard for Pulverized Fuel Systems –1997 Edition – is Obsolete and consolidated in
NFPA 85 – Boiler and Combustion Systems Hazards Code – 2001 Edition (NFPA 85 is consolidation of NFPA 8501,8502,8503,8504,8505 &8506) Clauses applicable for Knife Gate valves for pulverized fuel application in NFPA 85 :1.3.171 1.3.171.1 Valve Barrier Valve – A valve, not necessarily gas tight, used to inhibit hot gases from traveling back into any system component open for inspection or maintenance. Burner Shut-off valve – In a pulverized fuel system, a valve that is installed in the fuel line between the pulverizer and the Burner. Dust tight Valve – In a pulverized fuel system, a tight sealing valve installed in the fuel supply pipe to the burner to allow or stop flow. Vent Valve – a valve used to allow venting of air or gas from the system to the atmosphere. Pulverizer System Component Design Requirements All components of the pulverized fuel system as described below that are designed to be operated at no more than gauge pressure of 2psi(13.8 kPa) shall be designed to withstand an internal explosion gauge pressure of 50psi(344 kPa) for containment of possible explosion pressures. For operating gauge pressures in excess of 2 psi (13.8 kPa) the equipment as described below shall be designed to withstand an internal explosion pressure 3.4 times the absolute operating pressure.
1.3.171.2 1.3.171.5 1.3.171.9
6.4.6 6.4.6.1.1
6.4.6.1.2
6.4.6.1.3
6.4.6.1.4
Equipment design strength shall incorporate the combined stresses from Mechanical loading, operating, and explosion and implosion pressures plus an allowance for wear which shall be determined by agreement between the manufacturer and the purchaser. Some parts of the pulverized fuel system, such as large flat areas and sharp corners can be subjected to shock wave pressures. These pressures shall be included in the design, based on
Standards applicable:NFPA 8503 – Standard for Pulverized Fuel Systems –1997 Edition – is Obsolete and consolidated in
NFPA 85 – Boiler and Combustion Systems Hazards Code – 2001 Edition (NFPA 85 is consolidation of NFPA 8501,8502,8503,8504,8505 &8506) Clauses applicable for Knife Gate valves for pulverized fuel application in NFPA 85 :1.3.171 1.3.171.1 Valve Barrier Valve – A valve, not necessarily gas tight, used to inhibit hot gases from traveling back into any system component open for inspection or maintenance. Burner Shut-off valve – In a pulverized fuel system, a valve that is installed in the fuel line between the pulverizer and the Burner. Dust tight Valve – In a pulverized fuel system, a tight sealing valve installed in the fuel supply pipe to the burner to allow or stop flow. Vent Valve – a valve used to allow venting of air or gas from the system to the atmosphere. Pulverizer System Component Design Requirements All components of the pulverized fuel system as described below that are designed to be operated at no more than gauge pressure of 2psi(13.8 kPa) shall be designed to withstand an internal explosion gauge pressure of 50psi(344 kPa) for containment of possible explosion pressures. For operating gauge pressures in excess of 2 psi (13.8 kPa) the equipment as described below shall be designed to withstand an internal explosion pressure 3.4 times the absolute operating pressure.
1.3.171.2 1.3.171.5 1.3.171.9
6.4.6 6.4.6.1.1
6.4.6.1.2
6.4.6.1.3
6.4.6.1.4
Equipment design strength shall incorporate the combined stresses from Mechanical loading, operating, and explosion and implosion pressures plus an allowance for wear which shall be determined by agreement between the manufacturer and the purchaser. Some parts of the pulverized fuel system, such as large flat areas and sharp corners can be subjected to shock wave pressures. These pressures shall be included in the design, based on