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

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Safety Shut-Off Valves
General Technical Specification
These shall shut-off in case the pressure on the upstream side of the valve becomes
less than preset values. The valves shall be of globe type for DN 50 and below and
butterfly type for sizes above DN 50; the material shall be suitable for service conditions.
The valves shall be actuated by electromagnetic or pneumatic device working in
conjunction with pressure switches located on the pipelines being safeguarded and shall
include all components required for its functioning.
Electrical continuity
Metallic electro static jumpers shall be provided at all locations on all flanged
connections, in case of flammable gases and oxygen. This is to prevent accumulation of
static electricity in pipe sections. Piping system shall be suitably earthed at a regular
length of pipeline.
Measuring and control devices
Instrumentation and control devices shall be provided for monitoring the fluid distribution
system, regulation of pressure and flow.
Flow measurement shall be provided at battery limit of all production and consuming
units, inlet/ outlet piping of storage installations, on surplus gas bleeder piping to flare
system etc. When orifice plates are used, proper care shall be taken in piping layout for
preventing accumulation of condensate by providing suitable slope or drain system.
Requirement of straight length upstream and downstream of flow sensors shall be
maintained as per instrumentation requirements. Normally the straight length
recommended is 10 times pipe dia before inlet and 5 times pipe dia after outlet of device.
Pressure measurement shall be provided at battery limits of production and consumer
units, at outlet of storage systems, inlet and outlet of pressure regulators/ controllers, etc.
Pressure and Flow Control valves shall be provided at gas mixing stations, main
pressure regulating stations, flare stack piping, inlet/ outlet piping of storage installations
(gas holders). For low pressure gas lines, butterfly type control valves shall be used. For
high pressure gases, globe valves may be used. Sizing of control valves shall be based
on flow rate and pressure parameters.
02.12. HOSES & HOSE BOXES
General purpose oxygen and propane shall be provided with necessary isolating valves,
pressure control valves, Hoses & Hose boxes at each consumer points. Nipples along
with quick coupling hoses shall be provided for steam, compressed air and Nitrogen for
purging and other needs.
02.13. SPECIAL CONSIDERATIONS FOR OXYGEN PIPING
Filters should be installed in the oxygen pipeline system at the following points:
a) At the outlet of the oxygen plant.
b) Upstream of components having soft seating in contact with the oxygen stream e.g.
pressure regulator and control valves.
c) Upstream of components that have moving parts in contract with the oxygen stream e.g.
flow measuring and limiting devices.
Provision shall be made for safe and easy access for frequent cleaning and / or
replacement of the filter element. The larger capacity filters like (a) above should be
provided with differential pressure gauge for monitoring the condition and providing
Gases & Liquid Fluids
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GS-02