i. Any closed vessel exceeding 22.75
liters (5 gallons) in capacity which is used exclusively for generating steam
under any pressure and include any mounting or other fittings attached to such
vessels, which is wholly or partly under pressure when steam is shut-off.
ii. Any equipment which receives steam
condensate to produce flash steam that is used in Process, will fall under IBR
purview, irrespective of pressure and quantity of steam produced.
iii. Any equipment which receives steam
condensate to produce flash steam that is vented to atmosphere (without
isolation), will not fall under IBR purview irrespective of pressure and
quantity of steam produced.
- Piping:
i. Steam pipeline for which the design
pressure excceds 3.5 kg/cm2g.
ii. Pipe size exceeds 254 mm internal
diameter ( for any steam pressure).
iii. All steam / condensate pipelines
interconnecting equipment under IBR purview, irrespective of pressures.
iv. BFW pipelines from BFW pumps to
Boilers.
- Following are not in IBR scope –
i. Steam Tracing piping
ii. Heating Coils
iii. Heating Tubes in Tanks
iv. Steam Jacketed Piping
- All steam users (heat exchangers,
vessels, condensate pots etc) where outlet condensate is drained to atmosphere
or flashed to atmospheric pressure (as in a Deaerator) and vented
(without isolation) do not fall under IBR purview. The IBR specification break
in such cases is done at last isolation valve on the steam line upstream
of equipment.
- All steam users where the outlet
condensate piping is connected to an IBR equipment are covered under IBR.
In case of steam turbines even if the condensate is connected to an IBR equipment,
the steam turbine is not covered under IBR.
- Deaerator operating at 1.05
kg/cm2a pressure and the BFW pumps do not fall under IBR
purview. The BFW pump discharge pipeline to boiler falls under IBR
purview.
- Safety valves/ relief valves on IBR
system do not have isolation valve.
- Flash steam drums have to be provided a PSV without any upstream or downstream isolation valve.
- Main steam headers shall be protected from overpressure by provision of a set of 2 PSVs and also a PIC control valve.
- If a pressure reducing station or a desuperheater is provided in a steam line then the downstream of this pipeline after the desuperheater shall be protected by a set of PSVs. Set for lower pressure conditions, to take care of the possibility of malfunctioning of Pressure reducing station / desuperheater station which would result in high pressure steam being carried into lower pressure system.
