Q.NO QUESTIONS

1 WHAT IS THE OBJECTIVE OF THIS PLANT?

2 WHO HAS GIVEN THE BASIC TECHNOLOGY FOR THIS PLANT?

3 WHO DID THE DETAILED ENGINEERING AND CONSTRUCTION OF THIS UNIT?

4 WHOSE TECHNOLOGY IS USED IN GAS SWEETENING UNIT?

5 WHAT IS THE RATED CAPACITY OF THIS PLANT?The rated capacity of this unit is to handle an Hydraulic load of 9.0 MMSCMD feed gas.

6 FROM WHERE ALL THE FEED FOR THIS PLANT COME FROM?

7 HOW MUCH OF FEED IS COMING FROM EACH LOCATION?

8 WHERE THEY ARE RECEIVED FIRST INSIDE THE BATTERY LIMIT?

They are first received at the Dahej Terminal inside R-DMD.

9 WHAT IS THE PRESSURE AND TEMPERATURE AT THAT LOCATION?

10 WHO LOOKS AFTER THAT AREA?

11 WHAT ARE THE ASSOCERIES GIVEN AT THAT LOCATION BEFORE IT IS RECEIVED AT PLANT B/L?

12 DESCRIBE THE UTILITY OF THE ASSOCERIES?

The objective of this plant is to prepare feed for Gas Cracker unit i.e.,separating the C2C3+ components from the feed gas.

The Basic technology was given by KTI-FISH, USA. This company is taken over by M/S. Tecnip-USA in the year 2002

M/S. SAMSUNG-S.KOREA has done the detailed engineering and construction of this plant.

The Gas Sweetening Unit technology from M/S. DOW CHEMICALS is dow-tailed to this KTI TECHNOLOGY for process unit.

Feed Gas is received from three sources, viz., GAIL-Gandhar, GAIL-Hazira, PMT-JV-Hazira

The feed receipt from these locations are as under:(a) GAIL GANDHAR 3.6 MMSCMD;(b) GAIL HAZIRA 4.2 MMSCMD;(c )PMT-JV, HAZIRA 1.7 MMSCMD

The pressure maintained at that location is around 40 Kg/Cm2g; temperature is ambient.

M/S. PIIPL (Pipe line infrastructure India Pvt. Ltd.) based at Bharuch looks after the operations and maintenance of these pipe lines and the terminal.

There are pressure control system, emergency shut-off system, filters, gas measurement instruments and Pigging arrangements given at that location

Pigging arrangement is to do a periodic cleaning of these pipelines once in 5 years as required by the statutory authorities; all other systems are self explanatory.

13 WHAT ARE CONDITION OF THE FEED WHEN IT IS RECEIVED AT THE PLANT B/L?

At the battery limit of the plant the gas is received at 30 Kg/Cm2g and at Ambient temp.

14

15 WHAT IS THE FUNCTION OF VESSEL V-0101?

16 WHAT ARE ALL THE INSTRUMENTS CONNECTED TO THAT VESSEL?

17 WHAT IS THE FUNCTION OF EACH ONE?

18 WHAT ARE THE OTHER LINES JOINING TO V-0101?

19 WHERE THE LIQUID COLLECTED IN V-0101 IS SENT?It is sent to Closed Drain (CD)

20 WHAT IS GIVEN INSIDE THE VESSEL V-0101? WHAT IT DOES?

21 WHAT IS THE COMPOSITION OF THE FEED GAS DESIGNED?

22 WHAT IS THE NAME OF THE EQUIPMENT K-0101?

K-0101 is known as INLET-GAS Compressor.

WHAT ARE THE INSTRUMENTS AND FIXTURES GIVEN IN THE INLET LINE FROM B/L UP TO V-0101?Following are the instruments and fixtures given in the line till it reaches V-0101:FT/FQI/FIC-0202 to measure total inlet flow; PT/PIC/PV-0200 to control turbine inlet pressure; PT-0202 for pressure correction to FIC-0202; TI-0202 for temperature correction to FIC-0202; TI-0204 local indicator; PI-0203 local indicator; PSHH-0205 A/B/C switches with Trip Inter-Lock of the machine; Additional Pressure Control PIC-0201(PV value generated from PT-0200) to control Turbine Speed.Sampling arrangement SC-4 for manual sampling ;PSV-0206/0207 with I/V's on both sides ( set to pop at 49.3 Kg/Cm2g).

This is vessel is known as Inlet Gas separator and is given to remove any liquid coming along with the gas.

The level saddle hold a LG and a LT; a LSLL and a LSHH switch are also mounted on it.A pressure Gauge is given on the top of the vessel.

LG is for checking the level physically; LT measures the level and transmits to DCS for control. LSLL will caution and ensures the closure of LV-0215 for not blowing gas to blowdown. LSHH cautions to prevent liquid carry over into the compressor by tripping the machine (Vendor Inter-lock). .

There are two lines joining to this vessel, namely, the minimum flow by-pass line from discharge after cooler and the analyzers' (AI-0703,0630 & 0310) fast loop return.

A de-mister arrangement is given to prevent liquid carry-over and also for prevention of dust to go with the gas.

The design composition of the feed is as given below in MOL %:N2: 1.14; CO2: 3.36; C1: 82.93; C2: 9.36; C3: 2.99; C3+: 0.21

22 HOW MANY STAGES ARE THERE INSIDE THAT MACHINE?

This Inlet machine is a single stage compressor.

23 HOW MANY IMPELLERS ARE THERE FOR EACH STAGE?

There are 2 NO (S) impellers in the Inlet-Casing.

24

The suction pressure is around 30 Kg; the compression ratio is around 1.45--1.5

25 WHAT OTHER INSTRUMENTS / ARRANGEMENTS GIVEN IN THE SUCTION LINE?

26 WHAT IS THE DISCHARGE PRESSURE OF THE MACHINE?

The discharge pressure of the machine is around 44.5 Kg/Cm2g.

27 HOW MANY INTERCOOLERS/ AFTER COOLERS ARE GIVEN TO THIS MACHINE?

28 WHAT IS THE DESIGN DISCHARGE TEMPERATURE AND THE ACTUAL?

The design discharge temperature is around 75*C; in actual this remains around 60*C.

29 UP TO WHAT TEMPERATURE IT IS COOLED IN THE AFTER COOLER? HOW IT IS ACHIEVED?

30 WHAT DO YOU UNDERSTAND BY THE TERM SURGE?

Surge is a Head Vs Flow phenomenon for a measured speed of a Centrifugal machine.

31 HOW THIS MACHINE IS PROTECTED FROM REACHING TO THAT STAGE?

32 WHAT DO YOU UNDERSTAND BY THE TERM "CRITICAL SPEED"?

33 WHAT IS THE CRITICAL SPEED FOR THIS MACHINE K-0101?

The critical speed for K-101 is ------RPM.

34 HOW VIBRATION IS OCCURRING?

WHAT IS THE SUCTION PRESSURE AT THE INLET OF THE MACHINE AND WHAT IS THE COMPRESSION RATIO?

There is a strainer with a differential pressure measurement (PDI - 0231);PSLL-0225 with TRIP Inter-Lock;PSL -0224 for alert; PI-0226 for LCP; PT-0250 for Surge control;TI-0227 for LCP; TI-0230 for Surge control

Since this is a single stage machine there is only one after cooler E-0101is given for this machine.

The design outlet temperature of E-0101 is around 44*C; this is achieved by by-passing hot vapors across the exchanger by a TIC-0265.

The FIC-0250 given for Surge control gets the set point ZI-0250 from the Surge Control Calculation block; this block gets input signal from the following:Suction Pressure ; Suction Temperature ; Discharge pressure ; Discharge temperature & Discharge flow and sends the final output signal to the control valve FV-0250.

It is that speed near which more Vibrations are induced to the stator and the rotor.

Vibration can occur when the frequencies of Rotor and Stator come close to each other.

35 WHAT IS GIVEN TO MEASURE THAT PARAMETER?

BENTLY NEVEDA Vibration monitors are given to measure the Vibrations

36 HOW IT FUNCTIONS?

37 WHAT IS THE DRIVE FOR THIS MACHINE K-0101? GIVE ITS CODE NO.K-0101 is driven by a Turbine; its code No. is 50-TD-0301

38 WHAT IS THE MOTIVE STEAM PRESSURE?

The motive steam is given from VHP header at a pressure of 105 Kg/Cm2g

39 HOW MANY EXTRACTION STAGES ARE THERE FOR THIS MACHINE?

There are two stages of Extraction given to this machine.

40 STATE THE PRESSURE/TEMP CONDITIONS.

41 WHAT IS THE DESIGN OUTPUT OF THIS TURBINE IN TERMS OF POWER?

The design output of this machine is 23618 KW

42 WHY IT IS ESSENTIAL TO HAVE SUPERHEATED STEAM TO DRIVE THE MACHINE?

43 WHAT IS THE MINIMUM SUPERHEAT BELOW WHICH THE MACHINE SHOULD NOT BE OPERATED?

44 ALSO STATE THE MINIMUM PRESSURE AT WHICH THE MACHINE SHOULD BE STOPPED.

The minimum pressure below which the machine should not be run is 85 Kg/Cm2g.

45 HOW MUCH MAXIMUM STEAM CAN BE CONDENSED IN THE SURFACE CONDENSER?

The design max. capacity of condensation of the surface-condenser is @ 60 Mt/Hr.

46 WHAT IS THE CONDENSING MEDIUM? STATE THE OPERATING CONDITIONS ALSO.

47 WHAT IS THE DESTINATIONS OF THE EXTRACTED STEAM(S)?

The first stage of Extraction is at 42 Kg/Cm2g pressure with @ 400*C; the second stage of extraction is at 4.5 Kg/Cm2g with @ 170*C.

The turbine is designed to give output by both pressure and temperature energy; hence, it is essential to have enough superheat to achieve that.

A super-heat lower than 80*C (i.e.,340*+80*=420* C min) will cause more condensation at the end of the LP stages which can cause damage to the machine during high speeds.

Circulating Cooling water from CT-04 is the condensing medium; this comes at a pressure of around 4.2 Kg/Cm2g and at a temperature of 29*- 33*C; The Condensing pressure of the steam is about 0.17Kg/Cm2A

48 AT WHAT CONDITION STEAM ENTERS THE SURFACE CONDENSER?

49 HOW DO YOU MAINTAIN VACUUM IN THE SURFACE CONDENSER?

50 STATE THE PROCEDURE OF STARTING A SET OF EJECTORS?

51 WHAT WAY YOU WILL ENSURE THAT THE TRAPS ARE FUNCTIONING OK?

52

53

54 DESCRIBE THE STARTUP PROCEDURE OF THE MAIN TURBINE?

REFER SOP-EPRU-

55 WHAT IS THE CRITICAL SPEED OF THIS TURBINE UNIT AND THE TRIP SPEED?

HP steam is partly used inside the plant for running the C3R machine, partly in the stripper reboilers by reducing the pressure to 4.5 Kg/Cm2g and the balance is sent a export to the grid.LP Steam is totally utilized inside the plant, mostly in the stripper reboilers.

The steam enters the surface condenser at a Pressure of 0.17 Kg/Cm2A and at a temperature of around 52*C

Vacuum in surface condenser is maintained by removal of non-condensibles by ejectors. While starting the system the Start-up Hogger ejector is taken on-line which sucks the non-condensibles from the condenser and throws it to atmosphere. The motive steam for the ejector is taken from the SH extraction header.

After the turbine attains full speed with both the extractions started, the regular set of ejectors are put in service to conserve steam and the start-up Hogger ejector is switched off. Following is the procedure for taking the set of Ejectors on-line:(1) Flow of surface condensate through the ejector condensers are already established and the Hot-Well LIC is put on AUTO mode.(2) Motive steam header is prepared free of condensate.(3) The condensate traps are lined up to Hot-Well for one set of ejectors.(4) Motive steam to the primary ejector is first started and then the non-condensibles valve from the condenser is lined up.(5) Start motive steam to the secondary condenser.(6) Ensure for release of non-condensibles from the outlet of secondary condenser to atmosphere.(7) Ensure the proper functioning of the condensate trap.

If the trap is not functioning either it will stop water going to Hot-Well and water can be seen coming out from the vent; if it goes wide open then air will be sucked through the vent inside the system disturbing the working of the surface condensate pump immediately and slowly deteriorating the vacuum of the system.WHAT PROTECTION IS GIVEN IN THE EXHAUST OF THE TURBINE FROM GOING TO EXCESS TEMPERATURE?A water injection provision is given to spray DMW to the exhaust section when the temperature goes high during start-up.WHAT PROTECTION IS GIVEN TO SAFE-GUARD THE MACHINE NOT TO CROSS POSITIVE PRESSURE?A PSV is given in the condenser top to release steam out when the system pressure tries to come to positive side.

56 HOW WILL YOU CHECK THE TRIP SPEED OF THE MACHINE? CAN YOU DO IT IN RUNNING?

57 DESCRIBE THE LUBE OIL SYSTEM TO THE MACHINE(S).

58 WHAT ARE THE PROTECTIONS GIVEN TO AVOID DRY RUN?By pass valve is provided where oil is returned to tank.

59 WHAT IS THE IDEAL RANGE OF TEMPERATURE OF LUBE OIL?

The ideal range of Lube oil temperature to the bearings is 48*C to55*C

60 WHAT WILL BE THE EFFECT IF IT CROSSES THE MIN & MAX LIMITS?

61 AT WHAT VALUE THE HIGH TEMP. ALARM IS SET?

62

63 DESCRIBE THE PROCEDURE OF CHANGE OVER OF LUBE OIL FILTER AND COOLER?

REFER SOP-EPRU-

64 DESCRIBE THE SEAL SYSTEM OF THE UNIT K-0101? WHAT ARE THE TRIPS GIVEN TO THAT?

Primary seal is provided by discharge line stream & secondary seal is by nitrogen

65 WHERE DOES THE CONDENSATE FROM THE HOT WELL GO?

66 HOW MANY PUMPS ARE GIVEN TO PUMP THE CONDENSATE?

There are two pumps namely, 50-P-4002 A/B to pump condensate from V-4003

67 WHAT ARE THE INSTRUMENTATIONS ATTACHED TO THEM?

Tempreture Indicator-5936,5937 ; Pressure discharge Indicator-5966,5961

68 HOW WILL YOU KNOW THAT THE SEAL OF A VACUUM PUMP IS LEAKING?

Critical Speed of Turbine: 3200 RPMTrip speed of turbine: 10358 RPM

No; the trip speed cannot be checked during running. It is tested in decoupled condition after completion of any major over-hauling by by-passing the governor and increasing the speed manually. There are two trips given for Over-speed; one through the instrument and other by mechanical device.

Lube oil is supplied to turbine by MOP ( main oil pump) in nomal condition, in emergency supplied through AOP ( auxillary pump), EOP (emergency pump).

Lower temperature will increase the viscosity and will cause higher PDI across the filter and higher temperature will lower the viscosity and will make the oil loose its lubricating property.

WHAT IS THE MOTIVE STEAM PRESSURE AND THE EXHAUST PRESSURE FOR THE OIL PUMP TURBINE?The oil pump turbine's motive steam is SH steam at 42 Kg/Cm2g and the exhaust steamis LP steam at 4.5 Kg/Cm2g.

The Hot-well condensate after going through the ejector condensers go to E-4002-A, vent condenser and then it is sent to IOP along with the plant condensate from V-4003

69 DESCRIBE THE GOVERNOR CIRCUIT FOR STARTING AND VARYING THE SPEED

70 WHAT IS THE FUNCTION OF THE "CARBON BRUSH" ATTACHED TO THE TURBINE SHAFT?

71 HOW DO YOU ENSURE THAT IT IS HEALTHY?

72

73 WHAT ARE THE UNITS OF MEASUREMENT OF VIBRATION AND AXIAL MOVEMENTS?

Vibration is measured in "MICRONS" and Axial movement in "MM"

74 WHAT IS THE UNIT F-0101 CALLED? WHAT IS GIVEN INSIDE THAT EQUIPMENT?

75

76 IS IT POSSIBLE TO RUN THE PLANT BYPASSING THIS UNIT?

77

If the inboard seal of a vacuum pump starts leaking, it will start sucking air from theatmosphere and hence, the pump will get vapor-locked; the discharge pressure and the flow will get reduced leading to high level in the Hot well. If the outboard seal leaks then water will flow out from the seal.

Carbon Brush attached to the turbine shaft is mainly given to neutralize any stray current generated due to the high speed

Periodic checking is done by the Electrical department by way of measuring the gap Voltage and the physical condition at site.WHAT ARE THE OTHER PROTECTIONS GIVEN TO THIS MACHINE? GIVE THEIR TAG. NO(S) AND THE VALUES.

It is called Inlet Filter Separator. It has a filter cartridge holding unit at the top to hold 56.NO (S) of Cartridges and a liquid collector at the bottom.

HOW DO YOU KNOW THAT THIS EQUIPMENT IS PERFORMING WELL OR IT IS TO BE TAKEN OUT OF SERVICE ?

The differential pressure across the filter will be the deciding factor to continue or to take it out for cleaning or cartridge changing.

Yes, it is possible to run the unit by keeping this by-passed for cleaning; a 14" line is given across this unit for this purpose.WHAT IS THE REASON TO GIVE TWO LEVEL CONTROLS TO THE BOTTOM COLLECTOR IN THIS FILTER F-0201? WHAT IS THE CONTROLLER ACTION AND WHAT LOGIC IS ATTACHED TO THESE LV(s)?The filter unit has two compartments and they are separately connected to the two parts of the collector at the bottom. Hence two level controls are given separately for the individual sections. The action of LIC-0330 and LIC-0335 are "SNAP-ACTING"; based on the set point given in the LIC for high and low levels the control valve will open and close. LALL-0332 and LALL-0337 of individual sections will close these LV(s) when they are activated through the process logic to prevent gas blowing to the down-stream section. LAHH-0338 on the Gas O/L side is given with a logic I-02 to trip the system .

78 WHAT IS THE EQUIPMENT DOWNSTREAM OF THIS UNIT? WHAT IT DOES.

79 HOW MANY TRAYS ARE THERE IN COLUMN C-201?There are total 30 NO (S) of trays in this column.

80 DESCRIBE THE FLOW PATTERN OF THE STREAMS ENTERING AND LEAVING THIS COLUMN?

81 GIVE THE DESIGN OPERATING CONDITIONS OF THESE STREAMS AT ENTRY AND AT OUTLET?

82 WHAT ARE THE OPERATING VARIABLES OF THIS COLUMN?

83 WHAT FAVORS THE OPTIMUM OPERATION OF THIS COLUMN?

84

Yes; the original trays are changed to NYE type of trays from M/S. KOCH-GLITSCH

85 WHAT IS THE DESIGN PERCENTAGE OF CO2 IN FEED GAS AND WHAT IS EXPERIENCED?

86 WHAT IS THE DESIGN BASIS OF GSU-DBN?

The design basis of GSU-DBN is for handling 5.0% of CO2 in the feed gas.

87

88 WHAT WILL BE YOUR ACTION WHEN YOU NOTICE ANY OF THE SYMPTOM?

On the down-stream of this filter unit is the "AMINE CONTACTOR", C-0201. It is given to scrub the CO2 from the gas with the Ammine.

The Lean Amine enters the column from top, above tray No-1 and the feed gas enters the column below tray No-30 and goes up through the Chimney. The scrubbing takes place as the gas goes up the column by the Amine. The CO2 free gas leaves the column from top and the Rich amine loaded with Co2 leaves from the column bottom.

COUNTER CURRENT FLOWLEAN AMINE---462 m3/HrFEED GAS….337773 NM3/Hr

The operating variables are: (a) Quantity of CO2 in feed gas; (b) Feed Gas inlet temperature; (c) Lean Amine flow; (d) Lean Amine temperature; (e) Contactor Pressure A lean Amine temperature higher by minimum 5*C to the feed gas temperature ensures total scrubbing of CO2; the CO2 loading in Lean Amine should be less than 0.12. The flow of Lean Amine should follow the incoming CO2 in the feed gas (as per graph). The contactor pressure should always be > 42.5 Kg/Cm2g.DOES THIS COLUMN HAD UNDERGONE ANY MODIFICATION DURING GSU-DBN? DESCRIBE THE CHANGE IF ANY

The design percentage of CO2 in the feed is 3.36%; in actual the CO2 content is around 4.6% - 5.0%

WHAT ARE THE SYMPTOMS OF FOAMING IN THE CONTACTOR?WHAT ALL CAN CAUSE FOAMING?

The symptoms of foaming are two: (a) sudden increase in PDI of the contactor;(b) slippage of CO2 in the outlet gas.Foaming can be caused mainly by: (a) Low concentration of Lean Amine(<48%); (b) High particulates in the gas or in the amine (either dust or rust); (c ) Sudden increase of CO2 content in feed gas.

89 WHAT DO YOU UNDERSTAND BY THE TERM LOADING OF THE SOLVENT?

90

91 WHICH OF THESE IMPURITIES AFFECT THE PERFORMANCE OF THE SOLVENT.

92

93 WHERE DOES THIS RICH SOLVENT FROM CONTACTOR GO?

The Rich Solvent from the contactor is sent to Flash Vessel V-203

94

95 IS IT COOLED BEFORE SENDING TO THE NEXT STAGE?

No; it is heated with Lean Amine before it is sent to the Stripper as feed

96

97 WHAT ARE THE NEW EQUIPMENTS IN THIS ROUTE? WHY THEY ARE ADDED?

The immediate action is to reduce the plant feed rate to minimum of 6.5 MMSCMD until the problem is resolved.

Loading of the solvent is a measure of purity of Lean Amine; higher the loading means improper stripping of CO2 in the Stripper.WHAT ARE THE PARAMETERS ANALYZED DAILY FOR THE AMINE AND DURING SPECIAL TEST BY THE VENDOR?

The Amine is analyzed daily for Concentration and Loading.The amine is sent to the vendor for a complete analysis which includes:(a) Metals like Cr, Cu, Fe, K, Na, Ni, Ca; (b) CO2 Loading; (c ) Heat stable salts; (d) pH; (e) Foam Test; (f) ION Chromatography like Bicine, Formates, Chlorides, Oxalates, Sulphates, Acetates, Thiosulphate, Thiocynate.

High Iron Content, High Heat stable salts and the Ion's beyond the acceptable limits will affect the performance of the Amine.WHO IS THE SUPPLIER OF THE SOLVENT EARLIER AND AT PRESENT? WHAT ARE TRADE NAME(S) OF EACH.The original supplier of this solvent is by M/S. Dow through M/S. Amines and Plasticizers of India Ltd (CS-2010). The supply was changed to M/S. Ineos-USA, in the year 2004 (GAS-Spec CS-PlusTM). Presently the amine is used from M/S. BASF-Germany. It is called aMDEA

WHAT IS THE CONTROL INSTRUMENT AND THE LOGIC CONNECTED WITH THAT INSTRUMENT FOR SENDING RICH AMINE TO FLASH DRUM?The Rich Amine from the contactor is sent to Flash drum by the level controller of C-201 column LIC-0610; This LV-0610 will be made go close by LSLL-0613 of C-201 and by LSHH-0814 of V-203 vessel.

DESCRIBE THE PROCESS FLOW OF THE GAS LEAVING THE COLUMN UNTIL IT ENTERS THE DE-HYDRATOR.

The gas from the contactor first goes to V-201, Amine Scrubber for knocking off any liquid carried by it; then it is sent to V-0210 via E-0207, treated gas K.O drum, for further removal of any entrained liquid. Then the gas goes through the Inlet-Filter Separator for removal of any particulates and liquid. From filter unit the goes to the De-Hydrators,V-0202 A/B/C.

The new equipments in this route are E-0207 and V-0210; they are added to take care of the higher entrainment of Amine with the gas due to the higher flow rate caused by high CO2 %age in the feed.

98

99 WHY A SAFETY VALVE ( PSV-0651) ON V-0210 IS PROVIDED? WHAT IS IT'S SET PRESSURE?

100 WHAT IS SEPARATED IN V-203? WHAT IS ITS OPERATING PRESSURE?

101 WHERE DOES THE SEPARATED GAS END-UP?

The separated gas is normally routed to Fuel Gas; it can also be routed to Flare if needed.

102 WHAT IS THE DESIGN PRESSURE OF THIS VESSEL?

The design pressure of this vessel is 8.1 kg/Cm2g

103

104 HOW THE LEVEL OF THIS VESSEL V-203 CONTROLLED?

105 WHAT ARE THE LOGICS ATTACHED TO THIS VESSEL LEVEL?

106

This De-mister pad prevents any liquid going with the gas to Fuel-Gas

107

108

WHAT IS THE PROTECTION TO PREVENT GAS BREAKING THROUGH THE K.O. DRUMS V-0210 & V-0210?

The LALL-0623 & LALL-0651 of V-0201 & V-0210 will close the respective LV's upon Low level to prevent gas blowing to the low pressure vessel at the down-stream.

Since an I/V is given at the O/L of V-0201 and in the I/L of F-0201this PSV is given to take care of any blocked operation. It's set point is 49.3 Kg/Cm2g.

Any Hydrocarbon carried by the Rich Amine is removed in this vessel due to the flashing effect from 42.5 Kg/Cm2g to 5.2 Kg/Cm2g

IS THERE ANY MODIFICATION DONE TO THE INTERNALS OF THIS VESSEL? IF SO, WHY IT IS DONE?The vessel is internally cladded by SS sheet; this is done due to the observance of high corrosion and pitting on the shell

The level of this vessel is controlled at the outlet of the Rich Amine Vs Lean Amine exchanger by LIC/LV-0815 kept closer to the column.

This vessel level is provided with LALL and LAHH switches.LALL-0820 when activated will close LV-0815 to Stripper to protect the vessel going empty. LAHH-0814 will close LV-0610 of contactor bottom to protect the vessel from filling-up

WHAT IS THE FUNCTION OF THE DEMISTER PAD GIVEN IN THE INVERTED BOOT ON TOP OF THIS VESSEL?

WHERE IS THE FEED GAS ANALYZER SITUATED? THE ANALYZER AT THE INLET OF C-201 ANALYSES WHAT?

The feed gas analyzer is given at the filter separator F-0101 O/L. This analyzer AI-0310 analyses C1, C2, C3, C4, CO2 and N2

HOW MANY RICH AMINE / LEAN AMINE PFE'S ARE THERE IN THE PLANT?ARE THEY EXIST FROM BEGINNING?

There are three Rich Amine Vs Lean Amine exchangers (PFE Type) in the plant. The original design had only one; the other two are added during GSU-DBN

109 HOW MANY PLATES ARE THERE IN EACH EXCHANGER(E-201)?

There are 182 plates in two and in the third 242 NO (S) of plates are there.

110 WHAT IS THE DIFFERENCE BETWEEN A CONVENTIONAL EXCHANGER AND A PFE?

111

112 WHERE THE HEATED RICH AMINE IS SENT TO? STATE THE EQUIPMENT NUMBER.

The heated Rich Amine is sent to Amine Stripper, 50-C-0202.

113

There are 22 trays in this column. They are modified during GSU-DBN to superfrac trays.

114 GIVE THE OPERATING CONDITIONS OF TOP AND BOTTOM OF THIS COLUMN C-202.

Top :-0.7 kg/cm2 @ 98*C ; Bottom :-0.8 kg/cm2 @ 122*C

115

116 WHAT IS THE COOLING MEDIUM USED IN E-204?

The medium used in E-0204 is circulating Cooling Water from CT-04.

117 WHAT IS THE NAME OF THE VESSEL V-0211? IS THIS VESSEL NEW OR OLD?

118 WHAT IS THE NUMBER OF THE REFLUX PUMP? WHAT IS ITS CAPACITY?

119

The PFE's have very high heat transfer surface area than the conventional one due to the number of plates with very low clearances and high surface area.UP TO WHAT TEMPERATURE RICH AMINE IS HEATED IN THE PFE? HOW THE TEMP. CONTROL IS ACHIEVED?

The Rich Amine is heated up to 102*C in the PFE. There is no Automatic control of temperature available across these exchangers. A 3" by-pass line is given across Inlet of Lean Amine to Outlet of Lean Amine which can be used to reduce heating of Rich Amine in case the temperature goes up.

HOW MANY TRAYS ARE GIVEN IN COLUMN C-202? ARE THEY SAME AS DESIGNED OR MODIFIED DURING GSU-DBN?

IS THERE ANY REFLUX TO THIS COLUMN? WHAT IS ITS FUNCTION? WHAT IS REFLUX TEMPERATURE?

Yes; there is reflux to this column @ 15.8 M3/Hr (design). The reflux temperature is Around 40*C

V-0211 is called Amine stripper Ref.Drum. This is a new vessel replaced during GSU-DBN.

Reflux pump Tag No. is 50-P-0203 A/B. The pump has a capacity to pump 17.9 M3/Hr @ 4.81 Kg/cm2 Pressure.

WHY A DMW CONNECTION IS GIVEN TO THE REFLUX DRUM V-0211 AND AT WHAT CONTROL IT IS TAKEN TO THE VESSEL?

120 HOW IS THE PRESSURE OF THIS COLUMN MAINTAINED?

121 WHAT IS THE MATERIAL VENTED FROM V-0211? HOW MANY LINES ARE GIVEN FOR THAT?

122 WHAT IS THE PERMITTED AMINE CONTENT IN THE VENT GAS?

The permitted Amine content in the vent gas is 10 ppM max.

123 HOW MANY REBOILERS ARE THERE FOR THIS COLUMN? WHAT ARE THEIR NUMBERS?

There are two reboilers to the stripper namely E-203 and E-203 A.

124 WHAT IS THE REBOILING MEDIUM? FROM WHERE YOU GET THIS MATERIAL?

125 WHERE DOES THE CONDENSED MATERIAL FROM THE REBOILER ENDS UP?

126 UNDER WHAT CONTROL THE LP STEAM IS ADMITTED TO THE REBOILERS?

127

128 HOW WILL YOU KNOW ABOUT FLOODING IN THIS COLUMN?

129 AT WHAT PRESSURE THE SAFETY VALVES OF THIS COLUMN IS SET TO POP?

The PSV's 1005 & 1006 are set to pop at 3.5 Kg/Cm2g

130 UNDER WHAT CONTROL THE LEAN AMINE IS TRANSFERRED TO V-204?

The DMW is useful in adjusting the concentration of the circulating Amine; it is taken inside through a flow control FIC-1045.

This column is provided with two pressure controllers; PIC-1050 works on Split-Rangewith PV-1050 A, opening Nitrogen to the column in case of low pressure and PV-1050 B releasing gas to Atmosphere. PIC-1050C releases gas to atmosphere independently .

The material vented from V-0211 is carbon-dioxide (CO2). There are two lines given with a 10" and a 12" line.

The reboiling medium is LP Steam; this is obtained from the complex grid and also from the main turbine extraction

The condensate from the reboilers go first to the condensate pots V-209 and V-209 A and from there it is sent to V-4003 A for pumping to IOP.

The steam to the reboilers are admitted by the Level Control of reflux drum, LIC-1060, resetting the FIC-1030 on steam line, which ultimately varies the opening of FV-1030 and FV-1030 A on condensate O/L from V-209 & V-209 A. The LIC's on the individual pots will override the FIC on Low level.WHY IT IS ESSENTIAL TO LIMIT THE BOTTOM TEMPERATURE? WHAT WILL HAPPEN IF IT GOES MORE? Higher bottom temperature will lift more amine to the top and will increase the loss of solvent with CO2. A very high temperature can deteriorate the quality of Amine also.

The flooding in the column can be known by the differential pressure across the trays from PDI-1020

The Lean Amine is sent via Stripper level control LIC-1010 to V-204 Surge drum.

131 IS THERE ANY DRIVE IN THAT CIRCUIT?

132 WHAT IS THE FUNCTION OF PUMP P-201? NORMALLY HOW MANY PUMPS RUN?

Pumps P-201 A/B/C are called Amine Booster Pumps. Normally two pumps keep running.

133 WHAT ARE ALL THE INSTRUMENTATION CONNECTED TO THAT PUMP?

134 WHERE IS COOLER E-202 SITUATED? WHY AT THAT LOCATION?

135UP TO WHAT TEMPERATURE THE MATERIAL IS COOLED? UNDER WHAT CONTROL?

136 WHAT IS F-204? WHAT IS THE UTILITY OF THIS?

137

138 HOW WILL YOU KNOW THAT THE MATERIAL INSIDE F-204 IS EXHAUSTED FOR REPLACEMENT?

139 WHERE THE FILTERS F-0203/0203A AND 0205/0205A ARE KEPT?

F-0203/0203A are kept in the U/S of F-0204 and F-0205/0205a are kept in the D/S of F-0204

140 ON WHAT CONDITION YOU WILL CHANGEOVER F-203 AND F-205 ELEMENTS?

141 WHAT IS THE TYPE OF FILTER ELEMENTS ARE IN F-203 AND F-205?

They are cartridge type filters with the elements of 5 Micron size.

No; the material flows under available differential pressure; V-204 operates at 0.07 Kg/Cm2g pressure only.

LSLL-0939 of V-204 will trip these pumps. Any pump can be selected for AUTO-CUT service through the selector switch. Trip Logic I-08 is connected with these pumps. They have a common minimum flow by-pass arrangement through FIC-0940 to spill back into the surge drum.

Cooler E-0202 is kept at the discharge of booster pump P-0201 to cool the suction liquid of main Amine pumps P-0202 A/B/C.

TIC-0903 in the suction line opens TV-0903 to by-pass hot liquid across E-0202 to maintain the temperature

F-0204 is a filter filled with Activated carbon to remove de-graded / suspended impurities from the circulating Amine.What is the normal flow rate through this Carbon bed? At what pressure and temperature condition this is operated?

The flow through this bed about 10% of the total circulating amine. The operating pressure is about 3.5 Kg/ and Temperature is 57*C (presently it is 47*C)

The life of this bed is determined by the IODINE-No by qualitative test in QC;otherwise through the frequency of cleaning of F-205 & 205 A filter elements.

The PDI's given across each filter cautions beyond 3.5 Kg/Cm2g for changeover of the filter and to clean/change the elements of the exhausted one.

142 WHAT IS THE PROCEDURE FOR PUTTING A NEW CHARGE OF ACTIVATED CARBON ON LINE?

REFER SOP-EPRU-

143 WHERE IS ANTIFOAM ADDED TO THE CIRCULATING AMINE?

Anti-foam is added at the suction of the main amine circulating pumps P-202 A/B/C.

144 WHY IT IS NECESSARY TO ADD THIS CHEMICAL?

145 WHO SUPPLIES THIS CHEMICAL? AT WHAT DOSAGE RATE AND FREQUENCY IT IS ADDED?

This material is procured from M/S. Dow-Corning. It is added continuously @ 4 Lts/Day

146 WHAT KIND OF PUMPS ARE P-202 A/B/C?

P-0202 A/B/C are multi-stage centrifugal pumps with 4 stages..

147 WHAT ARE THE SAFETY INTERLOCKS ATTACHED WITH THESE PUMPS?

148 WHAT IS THE MAXIMUM FLOW THESE PUMPS CAN GIVE?

The maximum flow these pumps can give is around 510 M3/Hr.

149 HOW THE DRY RUN OF THIS PUMP(S) IS PREVENTED?

150 WHAT ARE THE PRESENT PROBLEMS EXPERIENCED WITH THE CONTACTOR LEVEL CONTROL VALVE?

151

152

153 WHAT IS THE NUMBER OF THE UNDERGROUND VESSEL?

The Tag No. Of this UG vessel is 50-V-0207.

This protects the amine from foaming during normal run in case of any variation in concentration of the amine.

These pumps are also connected with Trip Logic-08. When these pumps stop it will trigger that logic for a plant shut-down. Tripping of both the Booster pumps will also trigger tripping of these pumps to prevent damages to them by dry-run.

Tripping of both the Booster pumps will also trigger tripping of these pumps to prevent damages to them by dry-run.& by minimum circulation line .

Most of he problems faced were due to foreign material coming and sitting in the valve seat or the cage around, preventing smooth operation of this valve. The valve itself had got stuck at fixed openings sometimes causing plant shut-down(s).WHAT PROBLEM IS FACED IN RICH AMINE LINE TO STRIPPER? WHY? WHAT REMEDY IS THOUGHT OFF?

Heavy vibration was experienced in the Rich-Amine line after the C/V. This was found to be from high flashing of CO2 after the valve to the distributor. This problem has been removed by changing distributor to flashing feed gallery.

WHAT IS THE SYSTEM GIVEN TO CONSERVE AMINE WHILE IT IS DRAINED FROM VARIOUS EQUIPMENTS?A closed Amine Drain collection system is given underground the plant from all those equipments and pipelines which handles Amine so that they all get collected in the under ground drain drum for re-use..

154 AT WHAT PRESSURE THIS VESSEL IS MAINTAINED AND HOW?

155 WHAT TYPE OF PUMPS ARE P-0204 A/B? WHAT ARE THE LOGICS ATTACHED TO THESE PUMPS?

156 WHAT ARE THE DIMENSIONS OF THIS VESSEL AND UP TO WHAT LEVEL IT CAN BE FILLED?

157 WHAT IS THE DESIGN PRESSURE RATING OF THIS UG VESSEL?

158 WHY A LOW PRESSURE ALARM PAL-6604 IS GIVEN TO THIS TANK?

159 WHAT IS THE JOB OF P-0206? HOW THIS GETS STARTED AND STOPPED?

160 HOW THE FRESH AMINE IS RECEIVED FROM THE VENDOR?

161 WHAT IS THE CAPACITY OF TANKS T-0201 & T-0202?

The capacity of Tank T-0201 is 318.0 M3 and the tank T-0202 is of 81.0 M3.

162 WHAT ARE THE LEVEL MEASURING INSTRUMENTS OF THESE TANKS?

The pressure of this vessel is maintained at 0.015 Kg/ by Nitrogen by a self actuated PCV-6625; another self-actuated PCV-6626 will release gas to atmosphere at safe location upon reaching 0.0225 Kg.

They are self priming type submergible pumps. They can be started/stopped independently by local switches. However, upon selection in remote mode it will start when the level reaches a height of 1220 mm and will stop when the level drops to 460 mm.

The total ID of this vessel is 1830 mm and the length is 6100 MM; The safe filling height is 1370 mm (LAHH is provided at that level). The level is measured by LT/LI-6605

It is designed for a pressure of 3.5 Kg on the higher side and for a Full Vacuum on the lower side.

This will alert the operator to check whether the inert-gas blanketing system is lined-up and is working alright or not as emptying out material from the vessel without blanketing may cause vacuum in the equipment.

Pump P-0206 is under ground vessel external sump pump. The starting and stopping of this pump is given with the PLC. LAH-6600 will start the pump and LAL-6600 will stop the pump when they are activated by their contacts. However, it can be started manually by the local switch also by changing the selector from AUTO to Manual mode. Pump running indication is also provided in the AUX panel in C/R.

Fresh amine can be received either in tankers or in drums. If bulk quantity is to be unloaded then it is first unloaded to the underground tank through the 3" nozzle given for unloading. From there it can be either pumped to the day tank-T-0201 or T-0202, or directly to the system through the 2" modification line by-passing the filter F-206. When small quantities are to be unloaded, (when UG tank is contaminated with drained Amine) then they can be unloaded directly into the Day tanks by hand pump through the 4" nozzle given in them.

LT/LI-6636 and LT/LI-6646 are the level measuring instrument for the respective tanks.

163 WHY A 2" DMW LINE IS GIVEN TO TANK T-0202?

164 IN WHAT WAY THE PSV's GIVEN IN THESE TANKS ARE DIFFERENT FROM THE OTHER PSV's?

165 WHAT ARE THE TAG NO(s) OF THE LOW PRESSURE ALARMS FOR THESE TANKS?

PAL-6637 and PAL-6647 are the Low Pressure alarms for these respective tanks.

166

167 WHAT IS THE NORMAL MAKE-UP RATE OF AMINE AND ADDITIVE?

The make-up rate with the present BASF material is @ 750 Kg/Month

168 UPON WHAT PARAMETERS YOU ADD THIS MAKEUP QUANTITY?

169 WHAT IS THE FREQUENCY OF SAMPLING OF RICH AMINE AND LEAN AMINE?

STATE THE PROCEDURE OF REGENERATION OF THE DRYER DESICCANT?

170 WHAT DO YOU MONITOR IN THAT RESULT AND WHAT IS THE REMEDIAL ACTION TAKEN?

171 WHICH INSTRUMENT MEASURES THE PRESSURE DIFFERENTIAL ACROSS F-0206?

PDI-6617 measures the differential across F-0206172 WHAT IS THE CONTROL ACTION OF LIC-0640 & LIC-0645?

173

Refer answer in Q.77

174 WHAT IS THE LOGIC ATTACHED WITH LSHH-0647?

As per Original design the amine and the additive are to be procured separately at full concentration. Tank T-0202 is known as make-up tank, where-in the concentrated material is pumped first from T-0201 and the dilution is done in tank T-0202 by mixing DMW in to it. That is why this provision is given to this tank.

They are more of PVRV type where-in at 300 mm positive pressure the excess pressure will be released out and when the pressure goes to (-) 25 mm, atmospheric air will be sucked in to the tank by them, as the design pressure of these tanks are 350mm (+) and 50mm (-).

WHAT ARE THE PUMPS GIVEN TO PUMP MATERIAL FROM TANKS T-0201 & 0202 AND WHAT LOGIC IS ATTACHED WITH THEM?

Pumps P-0205 A/B are known as Amine transfer pumps from these tanks. The are made to stop in case of low level in tank T-0201 by LSLL-6635 and by LSLL-6645 of tank T-0202 through the Logic I-20.

Make-up is done only when the total inventory goes down in the system keeping the concentration at required level; change in concentration is normally addressed by varying the DMW quantity.

Basically they are sampled to check the CO2 loading in both and Concentration in Lean Amine.

The control action is same as described for the LIC's of F-0101(inQ.77) as for F-201 WHY THERE ARE TWO LEVEL CONTROLS GIVEN TO THE SAME VESSEL? AND WHAT PROTECTION IS GIVEN TO PREVENT GAS BLOWING INTO FLASH DRUM?

175 WHAT IS REMOVED IN THE DEHYDRATOR?

Moisture is removed in the De-hydrators.

176 WHAT IS THE INLET LEVEL OF THIS IMPURITIES AND WHAT IS AT THE OUTLET?

177

178 WHAT IS THE MEDIUM EMPLOYED IN OUR DEHYDRATORS? WHO HAS SUPPLIED THIS?

179 GIVE THE LOADING SCHEMATIC OF THE DEHYDRATOR WITH QUANTITIES.

180

181

There are 56No(s) of cartridges in each filter with the micron size of 1.

182

183

184

LSHH-0647 when activated will trigger logic I-07 to shutdown the system for prevention of liquid carry over to De-hydrators.

The moisture content in the I/L is expected to be in the range of 700 ppM and at the outlet it will be NILWHAT ARE THE VARIOUS DRYING PROCESSES EMPLOYED IN CONTINUOUS PROCESS INDUSTRIES?

Various other dryout processes are:Drying out though filter beds; by dilution method using a second component; by evaporator/concentrators; by blowers; by adsorbents etc.

The process employed in this plant by adsorption using a Mol. Sieve 3A*. This is supplied by M/S. W.G. Grace

The vessel is filled with the different adsorbents as given below:Grace Sylobead MS 564 C----> 7200 KgsGrace Sylobead MS 562 C----> 43950 KgsBuffer Gel 59 ----> 1904 Kgs

WHY IT IS ESSENTIAL TO HAVE A FILTER AT THE DOWNSTREAM OF THE DEHYDRATOR? HOW MANY ARE PROVIDED? GIVE THEIR TAG Nos.The filter at the outlet of the De-hydrators are essential to stop any Mol.Sieve dust going to the PFE's in the cryogenic section along with the gas as the dust will block the gas passage of the (fine clearances) PFE(s). There are two in Nos viz., F-0202 A/BHOW MANY CARTRIDGES ARE THERE IN EACH FILTER? WHAT IS THE PARTICLE SIZE OF THE FILTER ELEMENT?

HOW DO YOU UNDERSTAND THAT A DRYER HAS SATURATED AND ISDUE FOR REGENERATION? The Analyzer at the filter outlet AI-0703 analyzes moisture content of the outlet gas. Increase in the moisture above 0.1 ppM indicates that the bed is saturated. However, in actual practice the dryers are changed over after a fixed time cycle.

NORMALLY HOW MANY DRYERS ARE IN SERVICE? ARE THEY IN SERIES OR IN PARALLEL? IS IT POSSIBLE TO RUN THE PLANT WITH ONLY ONE DRYER? IF SO, WHAT ARE THE IMPLICATIONS?

Normally two dryers are in service at a time; they work in parallel.Yes; it is possible to run with one dryer but the plant load has to be brought down to the extent that the other dryer gets enough time to regenerate.NORMALLY HOW MANY HOURS A DRYER IS ON LINE BEFORE IT IS TAKEN OUT FOR REGENERATION?

185

186

187 WHICH COMPONENT IS ANALYZED BY AI-0630? AT WHAT VALUE THE HIGH ALARM IS SET?

188 HOW MANY KV VALVES ARE GIVEN IN EACH DRYER? STATE THEIR SIZES ALSO.

189

190 STATE THE PROCEDURE OF REGENERATION OF THE DRYER DESICCANT?

Refer SOP-EPRU-

191

192 WHERE ALL THE FEED GAS GO FROM THE DEHYDRATOR D/S FILTER OUTLET?

A fresh sieve can be kept in line for about 16-18 hours before it is taken out for regeneration; as the aging takes place its run length will come down to minimum of 12 hours.IS IT POSSIBLE TO CHANGE THE TIMINGS OF THE ON-LINE HOURS OR IS IT A FIXED CYCLE OPERATION?Yes; it is possible to manipulate the On-LINE timings through the sequence timer adjustment.WHAT IS THE DESIGN PRESSURE DROP ALLOWABLE FOR THESE DRYERS? STATE THE INSTRUMENT No(S)The design pressure drop calculated is around 0.55 Kg in SOR and about 0.78 Kg in EOR. The Measuring instrument Tag No(s) are PDI-0732 / 0752 / 0772 for V-0202 A/B/C respectively.

AI-0630 analyzes CO2 content of the feed gas before it goes to the cryogenic section. The high alarm is set at 13 ppM.

There are total 6 No(s) of KV valves in each dryer. They are:14" - 2 No(s); one in Feed I/L and the other in Feed O/L.02" - 2 No(s); one across 14" feed I/L KV and the other across 10" REGN. O/L KV10" - 2 No(s); one in the REGN. O/L and the other in the REGN. I/L.

WHY A PdsH/ PdAH IS GIVEN ACROSS THE 14" FEED I/L KV AND 10" REGN.O/L KV IN EACH DRYER? When dryer is in service the PDI across the REGN. KV should read the difference between the feed gas pressure and the REGN. header pressure and in the same way when Regeneration KV is opened and Feed gas KV is closed , then the PDI across the feed gas KV should read the same amount. Only then the RED color of the PdAH will go to white. This gives a clue about the tight closing of these KV's during operation and on Regeneration; if any difference is observed then the KV's have to be attended before the change over operation.

WHAT IS THE SIGNIFICANCE OF GIVING A HIGH TEMPERATURE ALARM IN THE DE-HYDRATOR O/L LINE TO FILTERS?TI-0715 in the O/L header is given with an alarm to indicate about the insufficient cooling of the regenerated dryer while it is taken on line. It may damage the filter cartridges also & MOC of cryo PFE's. There is a system trip Logic given with TAHH-0716 through I-03

The feed gas from the O/L of the filter-0202 A/B goes to Booster Compressor suction; in case of this Booster compressor not running then it can go directly to Warm Gas exchanger E-0310 and to DM reboilers. A small quantity is directed to go to the Flare header ( a 1" line with a FO)) and also to the Cold blow down header (1" line with a FO).

193

194 WHAT TYPE OF MACHINE IS EMPLOYED FOR PROPYLENE REFRIGERATION SYSTEM?

It is a two stage centrifugal machine .

195 STATE THE DRIVE AND ITS INLET / OUTLET CONDITIONS.

It is driven by a back pressure turbine from 42.0 Kg/Cm2g (HPSteam) to 4.5 Kg (LP Steam)

196

197 HOW MANY STAGES AND IMPELLERS ARE THERE IN THIS COMPRESSOR?

There are two stages with 6 No(s) of impellers in it. (3 Impeller per stage).

198

199

The lowest temperature achievable with this external refrigeration is (-) 39.5*C

200

201 WHAT IS THE INCOMING AND OUTGOING CONDITION OF THIS REFRIGERANT?

202

UP TO WHAT TEMPERATURE IT IS COOLED IN E-0310? WHICH IS THE NEXT EXCHANGER AFTER E-310? UP TO WHAT LEVEL THE FEED GAS IS COOLED THERE?The part gas going through E-0310 is cooled down to (-)31.5*C and then it is sent to E-0302, to get cooled down by C3R to (-) 40*C.

WHAT IS THE MINIMUM AND MAXIMUM LEVELS OF TEMPERATURE AND PRESSURE THAT SHOULD NOT BE EXCEEDED FOR THE INLET FLUID?The Inlet fluid's pressure should be between min 0.25 to 0.4 max with their corresponding temperature of (-) 40*C to (-) 30*C for Process requirement.

EXPLAIN THE LUBE OIL / SEAL SYSTEM AND THE OTHER AUXILIARY ITEMS GIVEN FOR THIS MACHINE?Lube oil system is supplied through MOP in normal condition which is turbine driven in case of emergency lube oil supplied through AOP. Primary seal gas is supplied from dischage of K-1001 line & secondary seal is provided through nitrogen . WHAT IS THE LOWEST TEMPERATURE IT CAN BE ACHIEVED USING THIS EXTERNAL REFRIGERATION?

IS THERE ANY ADDITIONAL REFRIGERATION USED DURING ANY ABNORMAL (HEAVY) FEED CONDITION? FROM IT IS COMING? Whenever Rich Gas is received as feed then an additional refrigeration is provided to cool the gas between E-0310 O/L to E-0302. This is basically to condense the possible heavies and to separate them in V-V-0330 (Gas Separator-1). The condensed HC liquid is sent to DM column as bottom feed. The gases are further cooled in exchanger E-0302 The refrigerant for this exchanger is obtained from GCU and the Vapors sent back to them.

The Liquid Refrigerant is coming from V-1001 & PTD @ 41*C & vapours outgoing after providing chilling @(-) 45*C .FROM WHICH STAGE THE CHILLING MEDIUM IS sent TO E-0302? UP TO WHAT TEMPERATURE THE GAS IS COOLED IN IT?The chilling medium is sent to E-0302 from V-1002 vessel; this exchanger floats with V-1003 vessel at (-) 40*C, the lowest temperature stage. The gas hence, gets cooled down to (-) 40*C.

203 PROPYLENE TURBINE ANTISURGE OPERATION IS POSSIBLE FROM WHICH PANEL / PANELS?

204 STATE THE VARIOUS INSTRUMENTS GIVEN IN THE SUCTION AND DISCHARGE LINES.

205 STATE THE START-UP OPERATION OF THIS MACHINE.

REFER-SOP-EPRU-

206 GIVE THE ALARM AND TRIP VALUES OF VIBRATION AND AXIAL MOVEMENT PARAMETERS

207 DESCRIBE THE AUXILIARY SYSTEM GIVEN TO THIS MACHINE

as per ques 197

208

209

210 HOW THE DISCHARGE PRESSURE OF THIS COMPRESSOR IS CONTROLLED?

Propylene Compressor K-1001 anti-surge operation is possible from GHH Borsig panel . Propylene Turbine TD-1001 operation is possible through woodward P.C. .

The Various instruments given are:1 suct. Line 2nd suct.line Disch. Line

PT-3015 PT-3050 FT/FI-3020 FT/FI-3030 TAHH-3217LG-3201 IN BOOT LG-3202 IN BOOT TAH-3213TI-3235 ( for anti surge) TI-3225 TI-3215TI-3236 TI-3226 TI-3216PDI-3233 ( for stainer) PDI-3223PI-6000 FOR SIC PI-3210 PALL-3232 PALL-3222 PAHH-3212PI-3231 PI-3221 PI-3211PAL-3234 PAL-3224 PAH-3214

Values of alarm and trip for vibrations and axial movements are: PARAMETER TURBINE COMPRESSOR Alarm Trip Alarm Trip VIBRATION 60mic 85mic 60mic 85mic AXIAL MOVEMENT 0.45mm 0.65mm 0.45mm 0.65mm

THE DISCHARGE LINE PSV'S ARE GIVEN FOR WHAT ? IS IT FOR FIRE CASE OR FOR ANY OTHER REASON?The discharge PSV(s)' 3205 / 3206 are given to protect the lines from blocked operations as there is I/V given in the discharge line.FROM WHERE THE KICK-BACK LINE IS TAKEN? WHAT IS THE REASON FOR CHOOSING THAT LOCATION?The Kick-Back line is taken U/S of the Discharge B/V to enable the machine to be rotated without taking the discharge on line for testing purposes only; the machine cannot be run on full design condition without the discharge condenser on-line.

211 WHAT IS THE CONDENSING MEDIUM IN DISCHARGE COOLER E-1001?

Circulating CW is the condensing medium in E-1001

211

212 WHY V-1001 IS CALLED THE SURGE DRUM?

213 FROM WHERE YOU GET MAKE-UP REFRIGIRENT FOR THIS MACHINE?

The make-up C3R comes to V-1001 from PTD spheres pump.

214 WHY PSV-3105 IS CALLED THERMAL SAFETY VALVE? WHERE ITS DISCHARGE GOES?

215 WHAT DO YOU UNDERSTAND BY THE TERM "FIRE CASE" SAFETY VALVE?

216

PIC-3110 given on the surge tank V-01001 operates the PV-3110 across the condenser E-1001 to control the discharge pressure; however, this PIC will not take care of high pressure conditions

HOW THE QUENCH LIQUID IS MIXED WITH THE KICK-BACK? FROM WHERE THE QUENCH LIQUID COMES?

The quench liquid is sent by the temperature control instrument to the mixing nozzle through a sprayer for thorough mixing with the hot kick-back gas so that the temperature of the final gas entering is close to the operating temperature of the stage. The quench liquid comes from the Surge drum V-1001

Any change in the refrigerant requirement needs to be accommodated for smooth operation; this drum is selected to take the surges and , hence, this is called surge drum.

This PSV-3105 is given in the make-up line coming from PTD; since this line gets bottled up with liquid once the requirement is full filled it is necessary to protect this line from increase in pressure due to temperature ingress. That is why this is called thermal safety valve.

Those safety valves which are termed as FIRE-CASE does the job of releasing the calculated quantity of vapors generated , in case of the equipment getting heated by a fire directly. The sizing is done based on the fluid characteristics of vaporization rate during such heat ingress due to fire.

IS THERE A COMMON SURGE CONTROL FOR THIS MACHINE? IF NOT WHAT ARE THE SIGNALS GOING TO THE INDIVIDUAL CONTROL BOX? WHERE THE OUTPUT GOES?

Each stage is given with a separate surge control. Each control box gets the following input signals: FIRST STAGE SECOND STAGE1 Stage Flow -FT-3020 1 Stage Flow -FT-30201 stg. suct presws-PT-3015 2 Stg Suct.Press. -PT-30502 Stg Suct.Press. -PT-3050 Disch.Pressure- -- PT- 32101 Stg. Suct.Temp -TE-3235 2 Stg Suct.Temp -TE-32252 Stg Suct.Temp -TE-3225 Disch.Temp--- ---TE-3215

The output signal activates The output signal activatesMinimum Flow C/V--FV-3020 Minimum Flow C/V--FV-3030

217 WHAT IS THE C3R TOTAL SYSTEM DESIGN PRESSURE?

The total C3R system is designed for 20.7 Kg/Cm2g.

218 IS FIRST STAGE A DRY DRUM OR LEVEL IS MAINTAINED IN IT?

219 UP TO WHAT PRESSURE THE GAS IS COMPRESSED IN THE BOOSTER COMPRESSOR?

The gas is compressed up to 51.8 Kg/Cm2g in this Booster.

220 DURING PLANT START UP, AT WHAT CONDITION YOU WILL START EXPANDER BOOSTER COMP?

221 WHAT IS THE NORMAL SPEED OF THIS MACHINE AND WHAT IS THE OVER SPEED TRIP RPM?

The normal speed is around 16000 RPM; the overspeed trip is around 16800 RPM.

222

223 SEAL GAS IN EXPANDER -STATE THE SOURCES?

224 WHAT TYPE OF FLOW ELEMENT IS FT-2105?

The flow element is PILOT-TUBE type.

225

226 WHY IT IS REQUIRED TO CONTROL THE OUTLET TEMPERATURE OF E-0301? HOW IT IS DONE?

227The gas gets cooled down to (-) 31.5*C in E-0310

228 WHAT IS THE NORMAL / ALLOWABLE PDI ACROSS THIS EXCHANGER?

Yes; first stage is a dry drum. Its LAHH-3003 to trip the machine is set at 915 MM via Machine Inter-lock which is 25% of the total height of 3660MM of the vessel..

The Booster compressor is started after reaching to a load of 5.5 MMSCMD during start-up.

DOES THIS MACHINE REQUIRE ANY ANTI-SURGE ARRANGEMENT? IF SO WHY AND HOW IT IS CONTROLLED?Anti-Surge is necessary for this machine since, it is also a centrifugal type machine. The Anti-Surge controller box gets in-put signal from the suction flow FI-2105, suction pressure PT-2106 and the discharge pressure PT-2116. The out-put goes to the Anti-Surge C/V, FV-2105 .The seal gas is given from two sources, namely, from Res.Gas Discharge and from the Booster Comp. Discharge.

WHERE DOES THE 16" LINEP-21-028-D1A JOIN? STATE THE REASON FOR SELECTING THAT LOCATION.This line joins the down stream of exchanger E-0301. This line comes into operation whenever Booster compressor does not run; hence it is given at this location for smooth continuation of operation. This also facilitates total isolation of the Booster compressor system along with the discharge cooler for maintenance independently without stoppage of total plant.

The temperature of the gas at the O/L of E-0301 is controlled at 38.1*C through TIC-2146 by by-passing hot gases across the exchanger. This is done to supply heat to the DM reboiler and side reboiler E-303 & E-0312 respectively.UP TO WHAT TEMPERATURE THE GAS IS COOLED IN E-0310?

229 WHAT KIND OF EXCHANGER IS E-310? HOW MANY PASSES ARE THERE IN THAT ?

230 HOW MANY PASSES ARE THERE IN E-311? WHAT ARE THEY?

231

232 WHAT IS VESSEL V-0302? WHERE THE GAS AND LIQUID STREAMS FROM THIS VESSEL GO?

233 WHAT IS THE SET POINT OF THE PSV GIVEN ON THIS VESSEL?

The PSV-2335 given on this vessel is set to pop at 57.0 Kg/Cm2g.

234 WHAT IS THE LIQUID LINE METALLURGY? IS IT SAME ALL THROUGH?

235 LSLL-2322 WILL DO WHAT? WHY IT IS ESSENTIAL TO DO THAT?

236

237

238 WHAT IS THE FUNCTION OF PIC-2100? WHY THAT IMPULSE IS GIVEN AT THAT LOCATION?

The Normal / allowable PDI across this exchanger is 0.5 / 1.5 Kg/Cm2 respectively.

E-0310 is a plate frame exchanger, Brazed Aluminum type,with two streams exchanging heat in it.

There are four streams exchanging heat in this exchanger E-0311. They are (a) Feed Gas; (b) liquid from V-0301; ( c) V-0302, Cold Gas separator O/H; (d) Res.Gas from DM O/H.UP TO WHAT TEMPERATURE THE GAS GETS COOLED IN E-311? WHICH ARE THE STREAMS THAT GIVES COLD TO THIS STREAM IN THAT EXCHANGER?

The Gas gets cooled to (-) 60.8*C in this exchanger. Stream (b) stated above gives this chillness to this gas. However it a combination of all the three streams,i.e., streams (b), © & (d) which are responsible for this.

Vessel V-0302 is called Cold Gas Separator. Liquid stream goes directly to DM column as third feed through the vessel Level Controller LIC-2320; whereas the O/H stream goes via exchanger E-0311 to DM column as top feed.

The MOC up-stream of LV-2320 is D2K, (i.e. 600# rating with SS metallurgy); down stream of the LV is A2K(i.e., 150# rating with SS metallurgy).

It ensures liquid seal by closing LV-2320 incase of malfunctioning of LIC-2320. Otherwise feed gas will by-pass directly to DM disturbing the operation.HOW IS THE EXPANDER INLET TEMPERATURE CONTROLLED? GIVE THE TAG NO. OF THE INSTRUMENT.TIC-2130 IN THE INLET LINE CONTROLS THE IN-LET TEMPERATURE BY MANIPULATING TV-2130 ACROSS E-0310 Res Gas side.WHAT IS THE NORMAL PDI ALLOWABLE ACROSS INLET STRAINER? GIVE THE TAG NUMBER OF THIS INSTRUMENT. WHAT IS GIVEN TO REDUCE THE PDI?

The Normal PDI across the in-let strainer in Expander I/L is 1.5 Kg/Cm2g; Its tag No is Sp--21-10. If the PDI goes up due to moisture ingress then it can be reduced by injection of Methanol through the injection nozzle given specially for that; however any choking due to external particles cannot be removed by this .

239 WHAT IS THE SPECIALTY OF XV-2125 IN THE I/L OF THE EXPANDER?

240

REFER SOP-EPRU-

241 HOW THE SPEED IS CONTROLLED?

Speed is either controlled manually by HIC-2100 or by selecting PIC-2100

242 WHAT ARE THE SHUTDOWN LOGICS ATTACHED TO THIS MACHINE?

243 PDI-2107 MEASURES WHAT? WHAT IS THE MAXIMUM VALUE ALLOWABLE?

244 IS THERE ANY TRIP ON THE DISCHARGE TEMPERATURE OF THE BOOSTER COMPRESSOR?

There is no trip given on the Booster Compressor discharge temperature.

245 IF SO WHY IT IS ESSENTIAL?

Not relevant as there is no trip given

246 WHAT IS THE FUNCTION OF V-0303? WHAT IS THE SET VALUE OF PCV-2165?

247 WHAT TYPE OF FILTERS ARE GIVEN IN THE U/S OF PCV-2165?Cartridge type

248 UNDER WHAT CONTROL THE GAS GOES TO DM-BOTTOM REBOILER?

249 WHERE THE DM BOTTOM REBOILER OUTLET STREAM JOINS AFTER REBOILING DUTY?

It joins the cold gas exchanger O/L stream to go to V-0301, Exp. I/L separator.

250

PIC-2100 which is given at the bottom of DM column opens high pressure gas directly across the expander to DM column or to vary the speed of the expander to manipulate the feed coming to the column. (as feed) to boost up the pressure fast (the MOC of this column bottom portion is only LTCS.

This is a quick closing valve incase the machine trips

GIVE THE START UP AND NORMAL SHUT DOWN PROCEDURE OF THIS MACHINE.

This measures the differential pressure across the Booster Compressor inlet strainer Sp-21-01.The maximum allowable is 2.5 Kg/Cm2g.

V-0303 is called seal Gas volume drum. The PIC-2165 is a self acting type with pressure set at 49.0 Kg/Cm2g

DM bottom reboiler E-0303 O/L Vapor Temperature controller, TIC-2150, resets FIC-2150 to manipulate the feed gas flow to the reboilers.

GIVE THE DIMENSIONS OF DEMETHANIZER? WHY THE DIMENSION AT THE TOP IS LARGER THAN THE BOTTOM?It is 3350 ID X 6780 MM at top and 1830 ID X 29035 MM at bottom. Since the gas volume handled at the top section is almost 90 % of the feed the ID at that section is given larger.

251 GIVE THE DETAILS OF THE INTERNALS IN DEMETHANIZER.

252

253

254

255 STATE THE TEMPERATURES OF THE INLET AND OUTLET STREAMS TO AND FROM THE REBOILERS.

256

257 GIVE THE TEMPERATURE PROFILE OF THIS COLUMN FROM TOP TO BOTTOM.

Column top temp (-) 107*C increases to column bottom temp. (-) 15*C .

258 HOW MANY FEEDS ARE COMING TO THIS COLUMN AND AT WHAT LOCATION THEY ENTER?

259 FROM WHERE THESE FEEDS ARE COMING?

260

261 WHERE DOES THE SAFETY VALVE OUTLET GO? WHY IT IS DIFFERENTLY GIVEN FROM OTHERS?

Demethaniser internals (1) Three packed bed tray of IMTP material (2) 12 valve trays of SS material (3) 3 T-type distributor (4) 5 chimney traysHOW MANY LOCATIONS THE PDI IN THIS COLUMN IS MEASURED? GIVE THE TAPPING LOCATIONS WITH TAG NO(S).In 4 locations PDI measured (1) b/w 1st packed bed (2 )b/w 2nd packed bed tray (3) b/w 3rd packed bed tray (4) b/w 1st plate to 12th plateWHY TEMPERATURE INDICATIONS ARE GIVEN ACROSS EVERY PACKED BED? WHAT DOES IT INDICATE?Temp. Indications are given across every packed bed for watching concentration of SRG how gas liquifying & how much gas in vapor form.FROM WHICH TRAYS THE LIQUID IS DRAWN FOR THE BOTTOM ND SIDE REBOILERS? WHERE THE VAPOR JOINS?

From 1st & 12th tray liquid is withdrawn for side & bottom reboiler . Vapor line joins to downward direction of 1st & 12th plate.

For Side Reboiler :- In (-) 4.9*C , Out (-) 10.4*C For bottom Reboiler :- In (-) 32.5*C , Out (-) 61*C

WHAT IS THE MOC OF THE INLET GAS COMING TO THESE REBOILERS AND THE OUTLET STREAM LINE MOC?

3 feeds are coming to this column . They enter at (1) Ist packed bed tray (2) 2nd packed bed tray (3) 3rd packed bed tray

They are coming from (1) for Ist feed from cold/cold gas exchanger E-310 (2) for 2nd feed from expander booster compressor K-302 (3) for 3rd feed from from cold gas separator V-302HOW THE COLUMN PRESSURE IS MAINTAINED? AT WHAT VALUE THE COLUMN SAFELY VALVE IS SET?Column pressure ia maintained through PV-2100 (IGV valve , Jetty valve) . Column safety valve is set at 18.3 kg/cm2.

262

263 STATE THE CHANGE IN THE TEMPERATURE AFTER EVERY LOCATION.

264

For product when temp. going to (-) 15*C MOC changes from CS to LTCS.

265

266 WHERE THE MOC OF THE BOTTOM PRODUCT STREAM CHANGES? WHY?

267 If CRYOGENIC SECTION PRESSURE SHOOTS UP WHAT IS THE CONTROL MECHANISMAVAILABLE?

If cryogenic section pressure shoots up then there will be closing of IGV valve.

268 WHAT IS THE FUNCTION OF FIC-2560?

FIC-2560 is minimum circulation valve for pump P-301A/B.

269 DESCRIBE THE INSTRUMENTATION GIVEN IN THE PRODUCT WITHDRAWAL LINE.

The instrument given in product line is FIC-2580 and AI-2587 , AI-2588.

270

271 WHAT KIND OF SEAL ARRANGEMENT GIVEN TO PUMP P-0301A/B?

Methnol seal arrangement given to pump P-301A/B .

272 WHAT ARE THE LOGICS ATTACHED TO THAT PUMP?

Pump will trip at low level in demethaniser column.

273 WHAT IS THE OIL USED FOR THE SEAL OF THESE PUMPS?

Safety valve outlet goes to the atmosphere . It is different from others because of methane having very low temp. (-) 107*C it will destroy the moc of flare header (SS).WHAT IS THE NAME OF THE TOP STREAM AND STATE ITS PATH BEFORE ENTERING THE COMPRESSOR.

Name of the top stream is Lean Gas , Residue gas before entering it to residue gas compressor goes to cold/cold gas exchanger & warm/warm gas exchanger. (C-301----E-310----E-311----K-301)

Temp. change after every location is C-301(-)110*C----E-310(-)65*C----E-311(-)30*C---- K-301(+) 30*C.

HOW THE COLUMN METALLURGY IS PROTECTED FROM GOING TO LOW TEMPERATURE? WHAT ARE THE MOC'S USED ?

WHAT IS THE LOGIC CONNECTED WITH COLUMN LOW LEVEL? WHICH IS THE INSTRUMENT GIVES THIS SIGNAL?LIC-2550 is the logic connected with column low level . LV-2550 is the instrument gives this signal.

The MOC of bottom product changes after E-304 from CS to LTCS because of temp. changes from (-) 5*C to (-) 15*C.

WHAT ARE THE COMPONENTS GETTING ANALYZED IN AI-2587& 2588? STATE THE RANGES OF EACH COMPONENT.

The component analyzed in AI-2587 is H2O & The component analyzed in AI-2588 is CO2 in product line from C-301. The range of H2O which will be analysed in analyser is & the range of CO2 0ppm to 258 ppm.

274

275 WHY THEY ARE GIVEN? WHAT IS THE SET POINT FOR THESE PSV'S

276 WHAT TYPE OF EXCHANGER IS E-0304?

E-304 is kettle type exchanger.

277 UNDER WHAT CONTROL THE COOLING MEDIUM ENTERS THE EXCHANGER?

Under level control LV-2570 the cooling medium enters the exchanger.

278

279 WHAT IS THE DISCHARGE TEMPERATURE OF EACH STAGE AND HOW THEY ARE COOLED?

280

281 STATE THE ALARMS AND TRIPS GIVEN FOR THE MACHINE WITH VALUES?

282

283 DESCRIBE THE SURGE CONTROL AROUND THE MACHINE.

284 WHAT ARE THE PLACES THE DISCHARGE OF THIS MACHINE CAN GO?

Discharge of this material can go to GAIL-HAZIRA & GAIL-GANDHAR.

285

The oil used for the seal of these pumps is Methanol

WHERE THE PSV'S 2592 AND 2597 ARE LOCATED? WHERE THE MATERIAL WILL GO WHEN THEY POP?The PSV'S 2592 & 2597 are located on discharge line of P-301A/B . When they will pop up the material will go to Demethaniser column.

To avoid high discharge pressure to the E-304 . The set point for these PSV's is 26.7kg/cm2.

HOW MANY STAGES ARE THERE IN RESIDUE GAS COMPRESSOR? WHY IT IS REQUIRED TO GIVE THEM?

There are two stages in residue gas compressor . It is requried because of higher compression ratio.

Discharge temp of Ist stage is 95*C & it ts cooled to 40.6*C . Discharge temp. of IInd stage 100*C & it is cooled to 45*C HOW MANY SAFETY VALVES ARE GIVEN IN THE FINAL DISCHARGE AND WHAT IS THE SET PRESSURE FOR THEM?Two safety valves are given in final discharge & set pressure for them is 61.5 kg/cm2.

WHEN DM COLUMN PSV'S POP TO ATMOSPHERE WHY THE MACHINE DISCHARGE PSV'S DISCHARGE TO FLARE?

The surge control around the machine by FIC-2045 . Discharge goes back to suction of compressor.

UP TO WHAT TEMPERATURE THE METHANOL INJECTION CAN BE DONE? STATE THE REASON FOR LIMITING AT THAT TEMPERATURE

286 DESCRIBE THE METHANOL SYSTEM STARTING FROM THE RECEIPT OF THE MATERIAL.

287 WHAT IS THE DIFFERENCE BETWEEN THE SPEC-B1A AND B4A?

The SPEC-B1A means carbon steel & B4A means low temp. carbon steel.

288 STATE THE METHOD OF EMPTYING OUT A COLD LIQUID FROM A PRESSURE VESSEL?

First warming up to atmosphere temp. then drain through low temp. drain.

289 HOW WILL YOU START A COLD SERVICE PUMP?First providing chilling to achieve liquid temp.

290

291 WHAT COMES TO V-3302 AND WHAT COMES TO E-3301? WHY THEY SHOULD BE SEGREGATED?

292 WHAT IS THE FUNCTION OF E-3303?

293 WHERE ALL THE PLANT CONDENSATES ARE RECEIVED?

All plant condensates are received to V-4002/4002A

294 FROM WHERE THEY ARE GENERATED? WHERE IT IS PUMPED BACK?

They are generated from E-4001 , E-203/203A , E-205.

295 WHAT IS THE FUNCTION OF E-4002?

E-4002 is vent steam condenser which liquify vent steam flashed from V-4002.

WHAT IS THE CAPACITY OF E-3302? WHAT IS THE HEATING MEDIUM GIVEN FOR THIS VAPORIZER?Capacity of E-3302 is 0.252 MMK cal/hr. Heating medium for this vaporiser is L.P.steam.

Low tempreture drain header comes to V-3302 . Closed drain header comes to E-3301. They are segregated because of temp. diffrence. Low temp. drain having temp. in negative & closed drain having higher temp.

E-3303 is low tempreture drain tank superheater . It's function to superheat the vapors going to flare KOD.

The rated capacity of this unit is to handle an Hydraulic load of 9.0 MMSCMD feed gas.

At the battery limit of the plant the gas is received at 30 Kg/Cm2g and at Ambient temp.

The design discharge temperature is around 75*C; in actual this remains around 60*C.

Vibration can occur when the frequencies of Rotor and Stator come close to each other.

TEMP *C46*41*

The separated gas is normally routed to Fuel Gas; it can also be routed to Flare if needed.

There are 22 trays in this column. They are modified during GSU-DBN to superfrac trays.

F-0203/0203A are kept in the U/S of F-0204 and F-0205/0205a are kept in the D/S of F-0204

This material is procured from M/S. Dow-Corning. It is added continuously @ 4 Lts/Day

It is driven by a back pressure turbine from 42.0 Kg/Cm2g (HPSteam) to 4.5 Kg (LP Steam)