4 General Technical Specification of Bhilai Steel Plant, SAIL ...

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General Technical Specification
DN
Bleeder pipe dia. DN (mm)
(mm) Low Pressure Fuel gas Natural gas/Corex Gas
200 50 25
250 50 25
300 50 25
400 80 50
500 80 50
600 80 50
700 100 80
800 100 80
900 100 80
1000 150 100
1100 150 100
1200 150 100
1300 150 150
1400 150 150
1500 200 150
1600 200 -
1800 200 -
2000 250 -
2200 250 -
2400 250 -
2500 250 -
2800 250 -
3000 250 -
3200 300 -
3500 300 -
02.11. VALVES AND ISOLATING DEVICES
Isolating devices shall be provided in piping system for isolation of pipe sections as well
as for isolation of all other mounted accessories for the purpose of operation and
maintenance. They shall be suitable for the service conditions in all respects and located
suitably considering ease of operation and maintenance.
Isolation valves shall be provided at the following locations:
• On all pipe lines both at the source and at consumer ends
• On all branch pipes to individual buildings and shops
• On all bleeder / vent pipes, purge gas inlet points, drain points, sampling
connections, etc.
• On all by-pass lines for large valve, regulators, filters, moisture traps etc.
• Instrumentation tapping points.
Selection of Isolating devices:
The gas cut-off arrangement shall ensure the possibility of complete cut-off gas along
with fast and safe operation. Gate valves with rising stem shall be used normally for
isolation in piping system.
Pipe work for fuel gases such as Blast Furnace Gas, Coke Oven Gas, Converter Gas,
Mixed Gas with low operating pressure shall have some means of gas tight isolation of
sections of the pipe work to facilitate maintenance work. These may be water seals,
goggle valves, spectacle blinds, or gas tight isolators / slide plate valves, etc.
Necessary water pipe work shall be provided for water seal.
Gases & Liquid Fluids
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GS-02