i have an interview in Qatar Petroleum. So please provide
the all details abt fire & gas systems
Answer Posted / welcome4ujd
providing all details here is difficult, i will try to give
some basics.
The Fire and Gas system (FGC) is designed to give the
earliest possible warning and location of:
a) A fire in its initial stage.
b) A flammable gas leakage or accumulation up to the
lower explosive limit (LEL%).
c) Any toxic gas likely to be present up to the
occupational exposure limit (OEL).
the architecture is
Detectors(input)--detector interface module--Fire and gas
control panel--outputinterface module--interface relay --
output devices
Description of the items :
1- The detectors are Manual Call Points, Fire
Detectors or Toxic Gas Detectors.
2- All incoming detector field circuitry interface
with the Fire & Gas control panel (F & GCP) by means of a
detector interface modules.
3- The F&GCP (Fire & Gas control panel) looks at all
of the connected Inputs and acts on the information from
certain number of the inputs that agree. This is commonly
known as a 'voting' system.
4- Output interface modules receive the outputs from
the proccessing unit and provide to the output circuits
(Relays)
5- The Interface relay provides electrical isolation
between the plant and fire &Gas control panel and provide
the output devices with the required power for operation.
6- The output devices are either alarms(
audible /optical) and/or control circuits.
Normally a protected plant is divided into fire areas and
each fire area has its own detection, alarm, control and
extinguishing system (if used).
If both fire and gas detection are required, these systems
share common control panels.
The fire detection and alarm system has manually operated
call points and automatic smoke, heat and flame detectors
located in areas where a fire hazard may exist.
Manual initiation of critical control actions overrides any
software-based system.
A brief description of the types of detectors and output
systems is given on the following pages.
The type of a Fir & Gas control panel and associated
detectors/outputs depends on the type of the controller it
self.
Addressable type system
If the controller is intelligent type, the detectors will
be addressable types, which are individually identified at
the F&GCP via a data highway. If the detector is not
addressable type then it is normally connected through a
dedicated interface module located near to the detector.
The addressable detectors and detector interface modules
respond to regular polls from the control panel and report
its type and status on the same loop (normal, alarm, open
circuit, short circuit...etc.).
Traditional type system
If the controller is traditional type (composed of discreet
electronic modules), the detectors are of the traditional
type, which changes the value of the electrical current in
its loop via normal wiring connections.
Each loop is identified on the F&GCP as a Zone.
The zone could include one or more of the traditional
detectors.
The activated detectors can not be individually identified
on the F&GCP, only they can be identified by observing the
integral LED on their locations.
| Is This Answer Correct ? | 42 Yes | 3 No |
Post New Answer View All Answers
i want to know the interview format fot gail, instrumentation. pls answer me in habib.sami1003@gmail.com
dear friends, i have seen flow as the selection critriea in presure guage (bourdon tube) and i would like to know what is the relation between flow and performance of pressure guage other parameters i found in the data sheet are pressure max. 1ksc temperature max. - 50 deg c line size - 80NB operating range - 1ksc pr. guage range - 0-2 ksc thank u,
can u briefly explain aboutan aryton shunt multirange DC ammeter?
What is compensation for flow ? Why we use compensation ? What are the factors of different compensation ? We not use then what problems may happen ?
How can measure flow in oil line?which type of transmitter is generally used?
how to calibrate load cell
PT RTD Range: -200 to 500 degree celsius If I configured in DCS Lower range and Upper range . In face plate it shows red colour due to overa range how was the characteristics look If the temperature is more than operating range. how was the characteristics look . whether its in Resistance vs Temperature curve is Linear or Non linear
what is exact time to study dcs and plc cources
1.what is controller proportional gain 2.what is the controller intergral action time. 3.A proportional plus derivative controller that has a proportional band of 20% and a derivative action time of 0.1 minutes. Construct the shape of the output waveform for the triangular input if the input rises and falls at the rate of 4 units per minute.
why we are using digital signals for I/O & how to measure this signals is getting or not ?
What are the application of bernoulli’s theorem?
Explain why plc require in analog input 4-20amp & 0-10 volt?
how many type conductivity sensor ?
hye SAM acn u send your e mail id, so that i can solve my query through e mail?
please can any one tell me clearly about pid tuning i am confusing about this .how to tune pid easly?