CHAPTER 13 SPECIAL PROCEDURES 13.1 DESLUDGING OF DESALTER:
The Desalter is located in 1st stage PHT-1 after a successive preheat exchangers
i.e.(42E01,42E02a/b,42E03,42E04a/b,42E05,42E06&42E07) utilizing relatively low tempts. Fluids such as HN, VD, KERO, VGO, KEROCR, HDCR & KEROCR
respectively. The temp gain through this pht is 129-136 0C.service water/dm water /sour
water from atmos O/H &hot-well drum /stripped water from DHDS-SRU&MEROX is used for desalting which will be stored in a vessel (42v11). The water will be preheated to 122 in 42E55 using LP steam before injecting to desalter through 42PM3A/B pumps. In normal desalting process water will be mixed with Crude in the mixing valve 42-DPC-1101U/S of the Desalter (provision is there for a part of wash water@10% can be injected into Crude line u/s of 42e01). on mixing the undesirable salts present in the Crude get dissolved in the wash water and hence separated from Crude. the electrostatic field employed in the Desalter helps in breaking the oil-water emulsion and thus the two liquids phases separate out. the hot brine from the Desalter is sent to sour water stripper unit(Merox)for heat recovery and subsequent transfer to ETP(effluent treatment plant). Whenever observed the sludge in the Desalter by checking try-cocks/42li1102D radar LT the sludge is tube removed after informing Manager (production)/ETP/YSF.
The water injection to Desalter via Crude line and mix valve to be suspended by closing 42FC1102 from MOI as well as in the field block valve located at first floor and d/s of 42E07.and the wash water to be resumed through a3”line t/o from 42E55 and which is going to Desalter (at bottom shell) directly with a check valve and a block v/v located at north of Desalter. the water rate should be controlled from field only as there is no control from MOI except a flow indication of water(42fi1103).the wash water entry to Desalter is at the bottom where the sludge and emulsion is presented being separated out of Desalter through two types of outlets which are available. one is a normal4nos. of draw off lines
and joining to a 4”line and SDV1101 routing to ETP via MEROX. the second alternative out-let is through 3nos.of draw off lines and joining a 4”line with a gate v/v and it can be routed to CBD via 3”line.the routing provision is there from CBD to OWS and as well as to SLOPR/D by using 42PM26.the routing of the sludge and hot brine should be depended upon prime approval of the concern normal ,including power personnel/units. During this process all conditions of Desalter can be maintained normal, including power, pressure & tempt. And continue this process until the sludge is removed from Desalter by time-to-time check of try-cocks at regular intervals.
Once the sludge is removed and effluent water is clear closing the block valve from field can stop the online desludging process and Desalter’s normal wash water injection can
resume by opening the 42FC1103 and block v/v at 1st floor. The routing of clear effluent
water should restore as normal as earlier. the entire desludging process will take one hour duration only. The RADAR LT indication will change from 50%T0100% also during the process.
13.2 Chemical injections
Caustic of strength 5 0Be is injected to the feed booster. The flow should not exceed 4ptb
since higher rates result in preheat exchanger fouling and caustic embrittlement in the furnace tubes and connected lines the capacity of caustic injection pumps is 75lits/hr. Another guideline to ensure caustic rate is not high is the chloride level in the overhead drum water should be 20ppm(max).if chloride is high (around 50 to 60) indicates caustic is less.
Function of caustic: Crude contains cacl2,mgcl2 which hydrolyses to HCL at lower
tempt>400c.hence NaoH convertsCacl2 and Mgcl2 to NaCl, Thus minimizing formation
of HCl. This further reduces consumption of NH3 to control the O/H PH.
Cacl2+H2o 2Hcl+Ca(OH)2
Rcoona+Hcl Rcoona+Nacl NaCl formed escapes out with diesel rco and other streams.
Ammonia injection;1)maintain conc. of NH3 bet 2.5 to 3.0 wt.% in the charge drum.2)maintain water seal in the vent line of Nh3 drums to minimize loss to atmosphere.3)maintain pH6.8-7.2
NH3+Hcl NH4cl.
Corrosion inhibitor : now used in indigenous HENKEL ESK-52,which is injected to the reflux line and Crude tower o/h line. it protects the line by forming a film on the wall of the lines/tubes. this chemical has to be injected on a continuous basis ,otherwise the film formed gets removed and the metal again exposed to corrosion.
Demulsifier injection: stable emulsions can also be broken by use of demulsifier
chemicals .the amount of chemicals required depends on the nature of the emulsion, type of Crude and other operating conditions like residence time, tempt, etc , Tests should be made to ascertain the required chemicals injection rate for optimum operation of desalting unit. Following are the chemicals generally used.
Details of chemicals. S.N o NAME OF CHEMICAL PURPOSE OF USAGE Mix ratio MIXING CHEMICAL Dosage ratio LTs/hr
1 ESK50 Atmos. Filmer 1:2 SRN 6.9
2 N5186 Atmos. Filmer 1:10 SRN 5
3
PHILMPLUS-5K7
Atmos. Filmer 1:4 Naphtha/
Kero
6.5
4 ESK50 Vac. Filmer 1:2 VD 6.9
6 PHILM-PLUS-5K7 Vac. Filmer 1:4 VD 1.3 1 Atsuandm101 Dmf 1:2 Water 13.9 2 Sm.dychem Dmf 1:2 Water 11 3 Nalcods 537 Dmf 1:2 Water 16.6 4 Ec2429A Dmf 1:2 VD 12.9 5 2w157 Dmf 1:2 VD 10.4
1 Ec1005A Neutralizer(atmos) 1:10 Water 8.4
2 4h4 Neutralizer(atmos) 1:4 14.4
3 Ammonia Neutralizer(atmos) Cylind
er
4 5be caustic Neutralizer(atmos) 1:4 75
5 Dorf5123 Neutralizer(atmos) 1:10
6 Ec1005A Neutralizer(vac) 1:10 15.9
7 4h4 Neutralizer(vac) 1:4 33
8 Ammonia Neutralizer(vac) Cylind
er
9 5be caustic Neutralizer(vac) 1:4
10 Dorf5123 Neutralizer(vac) 1:10
13.3 General safety guidelines
The following are general safety rules applicable to all plant operations. these must be known to every-body and strictly observed by all.
Safety rules:
1. Smoking is to be prohibited inside the refinery premises 2. Usage of mobile/cell phones at approved locations.
3. If an employee clothing becomes contaminated with acids, caustics, alcohols, hydrocarbons etc, he must move to nearest safety shower for washing & bathing. 4. Defective tools should not be used
5. Use proper tool to proper work involved
6. Over stressing tools or equipment causes serious injuries
7. ISI mark safety belts are to be used when working 2meters above grade level to prevent serious injuries during falling/slipping
Falls are the second largest cause of accidental deaths. Following points are to be observed.
1. Failure to look around while going around the plant. 2. Running/jumping in work places
3. Standing on boxes,chairs,and make-shifts instead of ladders/platforms 4. Neglecting to use handrails and running on stairs.
5. Failing to face ladder when carrying objects on the same.
6. Tools and materials should not be dropped from heights. they should be carried down.
7. Standing/waiting under materials suspended by ropes.
8. Chains or cables should not be permitted. stay in the clear until material is well secured.
Electrical equipments:
1. Do not tamper with electrical apparatus. This is the work of qualified electrician 2. Do not remove light bulbs to plug in power equipment
3. Use only approved electrical fittings. The cover of electrical fittings in hazardous areas should be secured properly to avoid entry of explosive gases..
5. An electrical extension wire must not be used if it is in bad condition, laid through water or in such manner as to allow motors equipment to travel over it.
6. Employees should regard all electrical wires are as live as dangerous.
7. Never close a breaker /switch that has been opened unless authorized to do so by supervisor concerned electrical engineer.
8. All electrical breakers must be de-energized and locked before process equipment can be worked upon.
9. Though the equipment Is electrically isolated check physically in the field by pressing START button before the job begins.
10. All live fuse, lighting and power cabinets must be kept closed.
11. If an electrical power unit motivates moving machinery and it is necessary to make repairs to same then refer to and follow the electrical lock out procedure laid down by the plant management.
Safety rules for particular operations
The following safety instructions are to be followed for frequent operations in the plant. Sample & purge connections
Before opening a purge or sample connection, ensure that the product is tempt. so that there is no risk of initiating a fire or causing burns. Hot & heavy products are most dangerous as they are near their auto-ignition temperature. Sample connections for hot products are normally connected with a sample cooler. Vents & drains of hot products, which are not used regularly, should be capped or blinded. if a hot product is to be vented. Connect the vent to a cooling coil first before proceeding with the venting. Vents should always be opened slowly. Operator who opens to purge the sample connections should be present till the same is closed. The plug/blind if provided should be put back when the operation is complete.
Always open the upstream v/v fully and adjust the flow by the down stream v/v. this is done so that u/sv/v is always operable in case of frosting. Draining etc. of vessels should not be done unattended. Operator/technician should be presented as long as draining /venting is going on.
Isolation of safety valves;
Many safety v/vs are provided with isolation v/vs at u/s & d/s of the safety body. This is to facilitate the repair of the safety v/v. it is important to ensure that that this isolation v/v s is kept in open as per stipulations. When a safety v/v is to be taken out of line, bring the spare safety v/v in line or shut down the equipment if spare v/v is not there/provided.
Operation of furnace:
While lighting in a furnace it should be purged thoroughly with steam/air. Some-times a number of trials are to be made to light up the burner. It is important to purge the furnace every time a burner fails and trial for relighting is made. it should also be noted that each burner be lighted with pilot ¬ with the flame or heat of the adjoining fire/burner. Sometimes during a furnace shutdown all the burners are put-off. If it becomes necessary to light up some burners, do not forget to purge the furnace. Purging is to expel/remove the accumulated hydrocarbons inside to prevent explosions during lighting/relighting.
High point vents & relief v/vs discharges.
The hydrocarbons discharges from the high point vents & relief v/vs discharging to atmosphere pose hazard due to lighting. Such d/cs are normally provided with steam purging connections. It is essential to keep purge steam in these lines, especially in monsoons when there is like-hood of lightning.
Flare system operation;
It is important that pilot burners at the flare stack are always lighted. Always maintain a small flow of gas in the system to avoid ingress of air into the flare stack. Maintain proper hydraulic seal in the water seal drum at all times when flare system is operating.
13.4 Sampling procedures
Control tests provide the information to the operating staff for making necessary adjustments to get max. Out-put and on-spec. Quality products. The control tests are to be made at all steps to monitor the intermediate and final products whether or not they are at the desired level. Samples are taken and analyzed at regular intervals such that the operation of the plant is monitored and any deviation (from spec. will indicate some mal operation/malfunction of the plant), which can be spotted in time without undue loss of time and product. Sometimes samples are taken to find out the effect of certain changes brought about in the plant conditions. The samples are to be taken with great care so that the samples are of representative nature. The samples points are suitably located to provide representative samples. The frequency of samples collection , type of analysis and points where samples are to be collected are generally specified by the process people. During guarantee tests some additional samples can also be taken at higher frequencies, which will be specified in the procedures prior to test –run. The following guidelines are to be followed while collecting the samples.
13.4.1 Liquid sampling procedure (non-flashing type):
1. The person taking sample should wear proper safety clothing like face-shield, aprons, rubber-gloves etc, to protect face, hands etc.
3. Sample points usually have two v/vs in series. One gate v/v for isolation and globe v/v to regulate flow. Open gate v/v first and globe v/v next slowly after placing samples containers. After the sample collection close globe v/v first and gate v/v next. Then again open globe v/v to drain the content for congealing liquids. In case of bitumen sampling two gate v/vs are used the purpose of two gate v/vs is to facilitate poking in case of line got choked.
4. Sample v/v should be slowly opened first slightly to check for plugging. If suddenly the plugging released the liquid comes-out at a dangerously uncontrolled rate. Never tape the line to release the plugging. Call the maintenance to unplug the line. In case of congealing type samples, sample points are to be equipped with proper copper coil type steam tracer. it should be ensured that steam tracing is functioning properly.
5. The operator taking the sample should be careful to stand in a position such that the liquid does not spill on him at any cost and he has unobstructed way out from the sample point in case of accident. While taking dangerous toxic material for sampling, it will act as an observer for safety. Proper gas mask is to be used. It is advisable to stand opposite to wind direction in case of volatile toxic liquid. 6. Sample should be collected in clean, dry and Stoppard bottle. In case of
congealing samples use clean dry ladle/grabber/tin.
7. Rinsing of bottle is to be done thoroughly before collecting the sample.
8. Before collecting ensure that the content has been drained and fresh sample is collected.
9. Gradually warm-up the sample bottle/metallic tin by repeatedly rinsing before collecting the sample
10. Stopper the bottle immediately after collecting the sample
11. Attach a tag to the bottle indicating the details concerned and tests are to be carried-out.
13. For example, the color of the heavier distillates (in refinery), slowly deteriorates with time. So these samples should be sent to LAB at the earliest after collection. 14. The samples after collection should be kept away from any source of ignition to
minimize fire hazard.
15. Volatile samples (naphtha) should be collected in bottles and kept in ice particularly for some Critical tests like RVP. moreover sample should not be collected fully to maintain vapor phase.
13.4.2 High-pressure hydrocarbon liquid samples (flashing type)
1. The person-taking sample should wear personal protection appliances like apron, gas mark hand gloves to protect him.
2. Ensure that sample bomb is empty, clean & dry.
3. Connect the sample bomb I/l v/v to the sample point with flexible hose.
4. Open that I/l v/v of the sample bomb. Hold the sample bomb. Hold the sample bomb o/l away from person. Keep face away from h/c vapor and stand in such a way that prevalent wind should blow h/c vapor away. Open the gate valve of sample point slowly till full open. Then slowly Cracks open the regulating valve. One should be careful at the time of draining, because chance of icing is there. As a result the formation of solid hydrates is a continuing process, which leads to the plugging of v/vs.
5. When all the air in the hose and bomb are displaced as seen by the h/c vapor rising from the o/l of sample bomb, close the sample o/l v/v. allow a little quantity of liquid to spill to make sure that the bomb is receiving liquid. Frosting will be an indication of liquid spillage.
6. Allow liquid h/c to fill the bomb. When the bomb is full upon the specified level. Close the v/vs on sample point. Close I/l on the sample point.
7. Carefully disconnect the hose from the sample bomb. To allow for some vapor space in the bomb for thermal expansion in case of overfilling, Crack open the o/l v/v of bomb and d/s a small part of liquid. Close o/l v/v.
8. Closed sampling facilities are provided at some locations where it is not desirable to waste the costly product or if the material is toxic. For filling the sampling bomb, pressure drop across a control usually utilized or across pump s/c & d/s. air is expelled from the bomb after it is connected to the u/s of control valve. The bomb is then connected to the d/s of C/V or pump discharge side. The sample is then collected and bomb is detached after closing valves on the both sides. Send sample bomb to LAB for analysis.
9. Gas sample.
10. For collection of gas sample, which are not under high pressure and temperature, rubber bladders are used. For the operation under vacuum or low pressure, aspirator is used. For representative sample, purge the bladder 3 to 4 times with the gas and then take the final sample. Use of 3-way v/v with bladder/aspirator will facilitate purging & sampling.
11. Sample bombs are to be used for taking gas samples from high Pr & high tempt. Source. Procedure mentioned under item4.1.2 (is to be used
13.5 Induced fan placing
1. Ensure the field check-up of necessary dampers opening; lube oil & bcw systems, power to motor &house keeping jobs.
2. Keep stack damper wide open. 3. Check the ARCH.TEMP.400c.
4. Check and ensure stack & hot flue gas dampers opening indications in the field. 5. Ensure hydraulic oil coupling loading in the AUTO (horizontal indication) to load
from MOI & the lever is in UNLOCK position.
Note: hydraulic oil coupling loading can be done MANUALLY by changing the mode to manual (vertical position) in the field and lock the lever at required %of loading as and when required. During that time loading cannot be changed from MOI.
6. Keep loading position at0%42PC-5007(arch pressure) in MOI. Keep the inter locks1) fuel cut-off (PB5055)&Id fan failure bypass (PB5054) in BYPASS mode at MOI.
7. Start the fan in the field
8. Start loading fan from MOI by 5%on regular intervals in slow steps from PC-5007 only after resetting SOVPC-5007.check RPM&LOADING panel indications of SI&ZI
9. Ensure the conditions of fan in field before loading further. Often check heater firing.
10. Watch APH tempts while loading fan. To normalize APH conditions reduce openings of cold air by-pass & stack dampers slowly. When conditions are normal put-back the inter-locks on line. & Observe id fan performance.
13.6 Pump stuffing-box/bearing housing acid cleaning
1. Isolate pump s/c,d/s & w/p v/vs and allow some time for cooling.
3. Update BLIND REGISTER
4. Isolate power to motor/display DO NOT START tag/board.
5. Acid cleaning of BCW lines improves flow circulation reduces bearing tempts. 6. Isolate pump BCW, SEAL-OIL&SEAL-STEAM.etc
7. Ensure wearing of PPE during attending the job. 8. Keep equp.under maint.display board.
9. After the job is over, pressure-up with FLO and close vents bleeders connected. 10. Ensure BCW, SEAL FLUSHING&SEAL STEAM, POWER to motor etc.
11. Open w/p v/v slightly and displace stock to cbd/ows.afterwards keep pump in warm up condition.
12. Remove equt.under maint.display board. 13. Put blinds on CBD/FLO lines.
14. Finally update blind&gasket registers.
13.7 GAUGE GLASS ACID CLEANING
1. Isolate g/g both take-off v/vs 2. Depressurize the content to ows.
3. Ensure passing of v/vs. and release for acid cleaning 4. Ensure usage of PPE.
5. After acid cleaning, close all vents drains of g/g.
6. Slowly open bottom t/ov/v and see level is increasing in the g/g.open vent&drainv/vs at slightly to displace air and close. Open top t/ov/v .see the g/g level is representative with L threading. Cap-off drains&vents if any. During commissioning of vaccum G/Gs open top t/o v/v and then bottom t/o v/v, see the g/g level is representative.
13.8 Washing procedure for air-pre-heater:
Washing of air preheater should be carried out during outage of the APH.the washing process should be carried out rapidly without any interruptions, otherwise sulphuric acid will be formed by the dissolved heating surface deposits. This may leads to corrosion on the metal heating plates. Hot water washing is the best for it.
WASHING SEQUENCE;
Before washing it should be investigated whether the deposits on the heating plates can be dissolved by water/whether under influence of water they have a tendency towards cementing. In the later case high pressure washing may be required.
The washing drive unit is taken into operation. Ensure that the main and reserve drive units are switched –off. Operating instructions for washing unit should be studied carefully. Washing is carried out first along and subsequently against the airflow direction. The washing should be continued until the heating surface is absolutely clean&the drained off water has a PH of 6-6.8.During washing the water is to be routed to OWS with quenching of service water for not affecting ETP operations.
An immediate careful drying should follow the washing. This is affected best by the residual heat still existing in the furnace or by operating the forced draft fan. If the air preheater is restarted in poorly dried condition, it may easily plug again owing to the remaining moisure/muck.after washing the water drainage, lines should be well ventilated and dried in order to avoid here, too, the occurrence of outage corrosion.
Operating Procedure of APH;
By taking any part of the system on bypass it can be put to pre-start –up checks for smooth operation (i.e.open&close dampers etc.). Crack open test for stack dampers are normally provided in the field to ensure their operation. But since these might trip FD&IDFANS, SWITHES OR OVER RIDES FD fan by-pass and ID fan –stack damper bypass should be activated during the check. The bypasses should be removed after the checking is completed.
2) Start-up.
1. Open burner air registers as per burner instruction manual
2. Press lamp test button. Ensure display is normal otherwise rectify the fault. 3. Put all trips on bypass mode.
4. Open stack damper fully
5. Open all blinds/dampers in airlines and flue gas lines to and from air pre-heater. 6. Close airline bypass damper.
7. Start one Fdfan and adjust flow to about 40% of max. 8. Start up pilot’s burners after purging the heater.
9. Light main gas burners and ensure proper combustion. For this, the appropriate SDVs need tobe opened by resetting and taking trip bypass in line.
10. Increase FD fan load/heater through-out to desired level and let it stabilize
11. Though out above procedure, furnace draft pressure should be watched and should never be allowed to become positive. If it becomes positive, adjust fan capacity control such that it remains normal (0-2.5 mm WG)
12. Remove bypass on trips for FD fans 13. Start up ID fan with min.speed.
14. Increase Idfan capacity by manual control to max. Flow slowly, while watching draft pressure. It should remain in between (0-2.5mm.WG)
15. After Idfan is fully stabilized at required flow rate (determined by pr at arch and Orsat analysis), close the stack damper, taking air pre-heater fully in line. During
low flue gas flow through ID fan low tempt. Alarm at flue gas line out-let of APH may sound.
16. Put ID fan on auto control&remove on all trip circuits.
3) SHUT-DOWN;
If for some reason like maint. /breakdown of APH, forced draft fans, ID fan or any other part of APH system, this equipment has to be isolated with furnace still running, following procedure should be adopted.
1. Put stack damper opening&ID fan trip on bypass mode
2. Open stack damper keeping burner flames &heater draft stable 3. Stop ID fan. Switch over to natural draft mode
4. After ducting has become cooler, close all dampers. Insert blinds into ducts and isolate the system before carrying out any maint. Job.
13.9 Heater start-up (42F01)
FD FANS (START-UP)
1.keep the following inter-locks in BYPASS condition Fd fan A fail bypass
Fd fanA/B fail bypass Combustion air failure Fuel cut-off bypass Pass flow low low bypass Turn down in bypass
2.turn the key HS-5008 and open the discharge damper 3.start the fan in the field in MANUAL mode
5.load the fan from HC5001 AND OBSERVE ZI-5001 (HYDRAULIC OIL LOADING)&SI-5002 (RPM) INDICATIONS IN MOI&FIELD to know whether the fan is getting loaded.
FAN-B placing on line.
1.start the fan using the same procedure but using INTERLOCKS and SOV related to FAN-B.
2.ensure that when second FAN started its discharge damper is closed to avoid any reverse rotation of fan. After loading the fan to required speed open the discharge damper. T/D ACTUATED mode
In t/d actuation mode one fan will be running and the other will be standby. Once one fan started put the other fan in AUTO in field to cut in immediately if the running fan fails Put the standby fan fail bypass and FD FANA/B trip bypass interlock in BYPASS mode. Once normal operating conditions are reached put all other interlocks on line
T/D BYPASS MODE
In T/D bypass mode both fans will be running at 50%load
After both fans are started, put both fans are in AUTO mode in FIELD. Once normal operating conditions reached, put INTERLOCKS on line
After ensuring the equal% of output is given from HC5001/5002 take 42FC5003 on line. OPENING OF FUEL SDVS
FUEL GAS
1.ensure the following interlocks are in healthy conditions COMBUSTION AIR FAILURE BYPASS
FD FANA/B FAIL BYPASS
PASSES LOW LOW FLOWS IN BYPASS
If FUEL GAS SDV is tobe opened without FD FANS RUNNING BYPASS the above interlocks
2.put fuel gas LOW LOW PRESSURE interlock in BYPASS mode OPEN THE SDV by resetting SOV1403
NOTE: ensure all FUEL GAS PLUGCOCK VALVES are in closed position in field&PURGING OF HEATER before opening the SDVs.
FUEL OIL SUPPLY& RETURN SDVs
1.ensure the following interlocks are in healthy conditions Combustion air failure bypass
fd fan a/b fail bypass
passes low low flows in bypass
If FUEL OIL SDVs to be opened without FD FANS RUNNING BYPASS the above interlocks
2.put fuel oil LOW LOW PRESSURE interlock in BYPASS mode OPEN THE SDVs by resetting SOV1404&SOV1401
NOTE: ensure all FUEL OILVALVES are in closed position in field PURGING OF HEATER before opening the SDVs. ATOMISING STEAM header is to be commissioned.
ID FAN START-UP
1. ID FAN to be started only after ARCH temperature reaches 400c 2. Keep the following interlocks in BYPASS mode
3. FUELCUT-OFF&ID FAN FAILURE BYPASS 4. Start the fan from field
5. LOAD the fan from42PC-5007
STACK DAMPER CLOSING
1. Ensure smooth operating conditions including ID FAN running 2. Ensure FUEL CUT-OFF & ID FAN fail interlocks on line 3. Turn the key 42HC5006A/B to close position
4. Reset 42SOV5006
5. Control the damper position from HC5006 from 100% opening to 0% opening (totally closed)
6. Same procedure to be followed up for 42F02 heater following the respective interlocks.
NOTE:
1. DO NOT CLOSE THE STACK DAMPER WHEN HC-5006 OP IS O%.
1. IN CASE OF ANY PROBLEM DURING OPENING OF STACK DAMPER FROM MOI, IT CAN BE OPENED MANUALLY BY WINCH OPERATION AFTER DISCONNECTING THE INSTRUMENT AIR TO IT.
IMPORTANT: Ensure release condition of EMERGENCY PUSH BOTTON in the FIELD before start of heater activities.
13.9 Hardware panel details of 42F01
no. bypass
HS-5001C To stop FD fanA (also,
closes D/S damper)
PB-5051 a) 42-KA-01A failure
sensed by motor running indication and low air flow switch b)hydraulic oil flow low low switch
a) In case KA-01A fails under T/D bypassed mode KA01B will not take up 100%load b) In case KA-01A fails under T/D actuated mode KA-01B will not start.
When KA-01A needs to be started. When FD fan 01B running in T/D actuated mode. If not bypassed, KA-01A cannot be started, as always trip signal exists for the fan when it is not running.
HS-5002C To stop FD fan (also,
closes D/S damper) a) 42-KA-01B failure sensed by motor running indication and low air flow switch b) Hydraulic oil flow low low switch
a) In case KA-01B fails under T/D bypassed mode KA01A will not take up 100%load b) In case KA-01B fails under T/D actuated mode KA-01A will not start.
When KA-01B needs to be started. When FD fan 01A running in T/D actuated mode. If not bypassed, KA-01B cannot be started, as always trip signal exists for the fan when it is not running.
PB-5057 Failure of KA-01A&B
as sensed by total air
In case both fans fail heater
When FD fans are to be started
If not
flow low low
/individual motor
running indication put together/individual flows put together.
will not be tripped, due to this interlock (Fuel s cut-off will not take place)
during start-up. Fdfans cannot be started, as trip signal exists to the fans. HS5007C To stop ID fan. PB-5054 a) KA-02 failure as sensed by suction pressure HI HI and motor running indication
b) Hydraulic oil flow low low switch
Incase ID fan sack damper will not get opened due to this interlock During ID fan starting If not bypassed the fan can not be started as trip signal exists
PB-5053 Combustion air failure
as sensed by low flow switches
If combustion air fails heater will not trip due to this interlock (Fuel cut-off will not take place) During Fdfans start-up As always trip signal exists for the fans
PB-5055 Fuel gut-off as sensed
by fuel oil&fuel gas low low pressure put together
In case both fuels get
cut-off, stack
damper will not open and fans (FD&ID) will not trip due to
During FD fans start-up As always trip signal exists for the fans
this interlock
PB-5049 Fuel gas pressure low
low D/S of control valve
Fuel gas will not get cut-off due to this interlock For opening FG SDV As low low Pr.exists unless SDV is opened
PB-5050 Fuel oil pressure low
low D/S of control valve
Fuel oil will not get cut-off due to this interlock For opening FO SDV As low low Pr.exists unless SDV is opened Note: the following interlocks do not have bypass facility
1) ArchPr Hi 2) Arch Pr Hi Hi 3) ID fan S/C Temp.Hi
Reset push button Function
SOV-5001 To reset fdfan A hydraulic coupling (for
loading the fan after starting)
SOV-5002 To reset fdfan B hydraulic coupling (for
loading the fan after starting)
SOV-5006 To reset stack damper SOV (required to
close the damper from DCS as this air is supplied through this SOV)
SOV-5008 To reset Fd fanA D/S damper
SOV-5009 To reset Fd fanB D/S damper
SOV-1401 To reset FO return SDV(required to open
FO return SDV)
SOV-1404 To reset FO supply SDV(required to open
FO supply SDV)
SOV-1403 To reset FG SDV(required to open FG
SDV)
13.10 Heater start-up(42F02) FD FANS(START-UP)
1..keep the following inter-locks in BYPASS condition fd fan A fail bypass
fd fanA/B fail bypass combustion air failure fuel cut-off bypass
pass flow low low bypass turn down in bypass
2.turn the key HS-5108 and open the discharge damper 3.start the fan in the field in MANUAL mode
4.reset SOV5101
5.load the fan from HC5101 AND OBSERVE ZI-5101(HYDRAULIC OIL LOADING)&SI-5102(RPM) INDICATIONS IN MOI&FIELD to know whether the fan is getting loaded.
FAN-B placing on line.
1.start the fan using the same procedure but using INTERLOCKS and SOV related to FAN-B.
2.ensure that when second FAN started its discharge damper is closed to avoid any reverse rotation of fan. after loading the fan to required speed open the discharge damper. T/D ACTUATED mode
In t/d actuation mode one fan will be running and the other will be standby. once one fan started put the other fan in AUTO in field to cut in immediately if the running fan fails Put the standby fan fail bypass and FD FANA/B trip bypass interlock in BYPASS mode. Once normal operating conditions are reached put all other interlocks on line
T/D BYPASS MODE
In T/D bypass mode both fans will be running at 50%load
After both fans are started, put both fans are in AUTO mode in FIELD. Once normal operating conditions reached, put INTERLOCKS on line
After ensuring the equal% of output is given from HC5101/5102 take 42FC5103 on line.
OPENING OF FUEL SDVS FUEL GAS
1.ensure the following interlocks are in healthy conditions Combustion air failure bypass
fd fan a/b fail bypass
passes low low flows in bypass
If fuel gas SDV is to be opened without fd fans running bypass the above interlocks 2.put fuel gas low low pressure interlock in bypass mode
open the SDV by resetting sov2001
NOTE: ensure all FUEL GAS PLUG COCK VALVES are in closed position in field & PURGING OF HEATER before opening the SDVs.
FUEL OIL SUPPLY& RETURN SDVs
1.ensure the following interlocks are in healthy conditions Combustion air failure bypass
Fd fan a/b fail bypass
passes low low flows in bypass
If fuel oil SDV s to be opened without fd fans running bypass the above interlocks 2.put fuel oil LOW LOW PRESSURE interlock in BYPASS mode
NOTE: ensure all FUEL OILVALVES are in closed position in field&PURGING OF HEATER before opening the SDVs. ATOMISING STEAM header is to be commissioned.
ID FAN START-UP
2. ID FAN to be started only after ARCH temperature reaches 400c 3. Keep the following interlocks in BYPASS mode
4. FUELCUT-OFF&ID FAN FAILURE BYPASS 5. Start the fan from field
6. LOAD the fan from42PC-5107Once the conditions are normal put back the interlocks on line
STACK DAMPER CLOSING
1. Ensure smooth operating conditions including ID FAN running 2. Ensure FUELCUT-OFF&ID FAN fail interlocks on line
3. Turn the key42HC5106A/B to close position 4. Reset 42SOV5106
5. Control the damper position from HC5106 from 100% opening to 0% opening(totally closed)
NOTE:
1.do not close the stack damper when hc-5106 op is o%.
2.in case of any problem during opening of stack damper from MOI, it can be opened manually by winch operation after disconnecting the instrument air to it.
IMPORTANT: Ensure release condition of EMERGENCY PUSH BOTTON in the FIELD before start of heater activities.
13.11 Hardware panel details of 42F02
Push button no.
Interlocks bypassed
Effect When to bypass Why to bypass
fanA(also, closes D/S damper) PB-5151 a) 42-KA-03A failure sensed by motor running indication and low air flow switch
b)hydraulic oil flow low low switch
a)in case KA-03A fails under T/D bypassed mode KA03B will not take up 100%load b)in case KA-03A fails under T/D actuated mode KA-03B will not start. When KA-03A needs to be started.. When FD fan 03B running in T/D actuated mode. If not bypassed,KA-03A can not be started as always trip signal exists for the fan when it is not running. HS-5102C To stop FD fanB(also, closes D/S damper) a) 42-KA-03B failure sensed by motor running indication and low air flow switch
b)hydraulic oil flow low low switch
a)in case KA-03B fails under T/D bypassed mode KA03A will not take up 100%load b)in case KA-03B fails under T/D actuated mode KA-03A will not start. When KA-03B needs to be started.. When FD fan 03A running in T/D actuated mode. If not bypassed,KA-03B can not be started as always trip signal exists for the fan when it is not running.
PB-5157 Failure of
KA-03A&B
In case both fans fail heater will
When FD fans are to be started
If not bypassed Fdfans can not be
as sensed by total air flow
low low /individual motor running indication put together/indiv idual flows put together. not be tripped ,due to this interlock(Fuel s cut-off will not take place)
during start-up. started as trip signal
exists to the fans.
HS5107C To stop ID fan. PB-5154 a)KA-04 failure as sensed by suction pressure HI HI and motor running indication b)hydraulic oil flow low low switch
Incase ID fan sack damper will not get opened due to this interlock
During ID fan starting
If not bypassed the fan can not be started as trip signal exists PB-5153 Combustion air failure as sensed by low flow switches If combustion air fails heater will not trip due to this interlock(Fuel cut-off will not take place)
During Fdfans start-up
As always trip signal exists for the fans
as sensed by fuel oil&fuel gas low low pressure put together
get cut-off ,stack damper will not
open and
fans(FD&ID) will not trip due to this interlock
start-up signal exists for the
fans
PB-5149 Fuel gas
pressure low low D/S of control valve
Fuel gas will not get cut-off due to this interlock For opening FG SDV As low low Pr.exists unless SDV is opened PB-5150 Fuel oil pressure low low D/S of control valve
Fuel oil will not get cut-off due to this interlock For opening FO SDV As low low Pr.exists unless SDV is opened
Note :the following interlocks do not have bypass facility 1)ArchPr Hi 2)Arch Pr Hi Hi 3)ID fan S/C Temp.Hi
Reset push button function
SOV-5101 To reset fdfan A hydraulic coupling(for
loading the fan after starting)
SOV-5102 To reset fdfan B hydraulic coupling(for
loading the fan after starting)
SOV-5106 To reset stack damper SOV(required to
close the damper from DCS as this air is supplied through this SOV)
SOV-5108 To reset Fd fanA D/S damper
SOV-5109 To reset Fd fanB D/S damper
FO return SDV)
SOV-2002 To reset FO supply SDV(required to open
FO supply SDV)
SOV-2001 To reset FG SDV(required to open FG
SDV Note :the following interlocks do not have bypass facility 1)ArchPr Hi 2)Arch Pr Hi Hi 3)ID fan S/C Temp.Hi
Reset push button function
SOV-5201 To reset fdfan A hydraulic coupling(for
loading the fan after starting)
SOV-5202 To reset fdfan B hydraulic coupling(for
loading the fan after starting)
SOV-5206 To reset stack damper SOV(required to
close the damper from DCS as this air is supplied through this SOV)
SOV-5208 To reset Fd fanA D/S damper
SOV-5209 To reset Fd fanB D/S damper
SOV-1304 To reset FO return SDV(required to open
FO return SDV)
SOV-1303 To reset FO supply SDV(required to open
FO supply SDV)
SOV-13SOV-1302 To reset FG SDV(required to open FG
13.13Procedure for unit CRUDE FEED TANK change over
1.unit feed rate is to be dropped to 440m3/hr 2.Desalter wash water injection is to be taken out
3.Desalter agar probe to be set in between70to75% and to be confirmed with try cocks level (2&3) in the field by physical check. In case of any Desalter grid voltage/amperes fluctuations, level can be reduced to suit operating conditions but it should be informed to unit manager
4.after feed tank switch over, the plant should be observed for ONE hour at 440m3/hr feed rate for stabilization, before bringing up the feed rate to the desired level at regular steps
As the feed tank change over activity is more Critical due to presence of water/sludge carry over in the Crude feed tanks. Hence the above factors are to be followed.
13.14 LEL DETECTORS STATUS
S.No Tag. no. Location Type remarks
1 42-AT-5007 42KA01A HC INFRA-RED
2 42-AT-5008 42KA01B HC INFRA-RED
3 42-AT-5107 42KA03A HC INFRA-RED
4 42-AT-5108 42KA03B HC INFRA-RED
5 42-AT-1501 42PM5A/B HC INFRA-RED
7 42-AT-1602 42PM35A/B HC INFRA-RED
8 42-AT-1701 42PM13A/B HC INFRA-RED
9 42-AT-1702 42PM14A/B HC INFRA-RED
10 42-AHH-1101 SOUR WATER O/F
AREA
HC
11 42-AT-001 NEAR CBD PUMP
AREA
HC INFRA-RED
12 46-AT-1601 46PM5A/B HC INFRA-RED
13 46-AT-1701 46PM8A/B HC INFRA-RED
14 46-AT-1801 46PM10A/B HC
15 46-AT-3001 46PM9A/B HC INFRA-RED
16 46-AT-2901 46V15 HC INFRA-RED
17 46-AT-2902 46V16 HC INFRA-RED
18 46-AT-2903 46KO1AREA HC INFRA-RED
19 46-AT-002 ANALYSER
ROOM
HC
20 46AE5207 46KAO1A H2S
21 46AE5208 46KAO1B H2S
22 42-AH-1603 42em30afc north HC INFRA-RED
23 42-AH-1604 42em30e/fafc north HC INFRA-RED
24 42-AH-1605 42em30i/kafc north HC
25 42-Ah-1606 42em30b/d afc
south
HC
26 42-Ah-1607 42em30d/f afc
south
HC
27 42-Ah-1608 42em30f/h afc
south
HC
28 46AH1602 VBU AFC SOUTH HC
29 46AH1603 VBU AFC NORTH HC
13.15 RADAR TYPE LTs
42LI1102D EMULSION PROBE
42LI1102E DESALTER SLDGE PROBE 42LI2601 CBD DRUM LEVEL
42LC2103 HVGO LEVEL 42LC2104 SLOP-CUT LEVEL
42LC2201 HOT WELL WATER LEVEL 42LI2202 HOT WELL OIL LEVEL
46LC1602 46V02 O/HH/C DRUM LEVEL 46LC1704 46V03 O/HH/C LEVEL
13.16 Guide lines for SR exchangers:
1.if SR flow >100m3/hr,all exchangers are tobe on line 2.42e51to54 exchangers are to be bypassed.
If>30m3<100m3/hr sr flow then e15,18A/B/C,&28 are in service.e25 is to be bypassed.E51,52,53&54 are to be kept parallel to e15,18,25&28.
3.for SR flow<30m3/hr,E15,25&28 ARE TO BE BYPASSED.E18 is to be in service.E51,53&54are to be parallel to E15,25&28 andE52 in service with E18.
13.17 Advanced process control logics.
Effects of Advanced process control logics during the emergencies are stated as follows
1)failure of ATMOS. heater(42F01):when 42f01 is tripped due to activation of 42SOV1403&42SOV1404 CLOSING, all except NSU-3(naphtha stabilizer) will get put-off automatically from APC CONTROL to OPERATOR mode.
2) Failure of 42F02 (VAC.heater) due to 42SOV2001&42SOV2002 CLOSING, only VHT-3&VDU-3 will put off automatically from APC to OPERATOR mode.
3) During 42PM01A/B OR 42PM02A/B tripping all APC CONTROLLERS put-off automatically from APC to OPERATOR mode.
13.18 Instrument air fail to open control valves in CDU-3 1.42PC1104 Desalter Pr 2.42dpc101 Desalter mix v/v 3.42HC1201 PH-2 spilt C/V 4.42FRC1201 PH-3spilt C/V 5.42FC1401 to 1404 42F01feed passes C/Vs 6.42dpc1420 42F01atomising steam C/V 7.42FC1501 Kero CR C/V 8.42FC1502 LD CR C/V 9.42FC1503HDCR C/V
10.42FC1504A Atmos O/H gas to flare 11.42FC1505 top Reflux C/V
12.42FC1701 stab. Feed C/V 13.42PV1701A stab.o/h gas to v-14 14.42FC1703 stab Reflux C/V 15.42HC1801 mix v/v on v-25
16.42FC1801 caustic circulation flow C/V 17.42HC1802 mix v/v on v-26
18.42FC1802 water circulation flow C/V
19.42FC2002 to 2005 42F02 feed passes flow C/Vs 20.42dpc2020 42F02 atomizing steam C/V
21.42FC2020 slop-cut recycle C/V 22.42FC2108 Sr quenches C/V 23.42FC2101 cold VD CR 24.42FC2102 VD (hot) CR 25.42FC2103 LVGO cold Reflux 26.42FC2104hot LVGO Reflux
27.42FC2105 hot HVGO Reflux 28. 42FC2106 cold HVGO Reflux
29 42FC1601 min.flow C/V on 42PM35a/b to v-13 30.42FC1704 min.flow C/V on 42PM14a/b to v-14 31.42FC1211 HD from e06
32.42HC1301 HDCR from e53 to 42c01 33.42FRC1203 LVGO from e11
34.42HC1202 LVGO from e21a/b 35.42HC1203 HVGO from e14
36.42FRC1206 HVGO from e24a/b/c/d 37.42HC1204 sr from e15a/b
36.42FRC1210 sr from e25 37.42PC7301 hp flow pr C/V
During oil gun dropping and placing oil fire keep stack damper wide position to prevent excessive pressure developing in the furnace
Remove oil fire
Purge oil gun with steam for some time to prevent plugging with fuel oil
Keep gas fire and pilot fires
Before dropping oil gun close oil and purge steam valves
Check burner in-side for oil accumulation through burner view ports
Use face shield and asbestos gloves during checking and dropping of oil gun
Keep burner drain at assembly open to drain oil inside, if any.
Do not allow oil gun more time without steam purging when gas fire is in-side as
the oil burner tip will get damage
If oil accumulation is not there gun can be dropped safely for cleaning
If oil accumulation is there then remove all fires and close air registers for cooling
before dropping
After dropping gun with face shield and asbestos gloves soak it in the soaking pit
after cooling
Remove outer barrel, inner barrel and tip etc burner parts for checking condition
and replace, if any, before assembling after cleaning
Fix gun with new lead gaskets
Purge the gun with steam for testing leaks, if any.
Ensure no leaks then keep oil fire ensuring gas fire in side by adjusting air registers
13.20 Procedure for dropping Fuel-gas/Hot well off gas burners
During dropping and placing Fuel-gas/Hot well off gas fire keep stack damper
wide position to prevent excessive pressure developing in the furnace
Remove Fuel-gas/Hot well off gas fire&oil and pilot fires&blind them. Also isolate air registers.
Purge oil gun with steam for some time to prevent plugging with fuel-oil
purge steam valves are to be closed
Check burner in-side for oil accumulation through burner view ports
Use face shield and asbestos gloves during checking and dropping of Fuel-gas/Hot well off gas burner tips
Keep burner drain at assembly open to drain oil inside, if any.
After removing all fires&closing air registers allow the burner to cool for 2to3hrs.
If oil accumulation is not there can Fuel-gas/Hot well off gas burners can be
dropped safely for cleaning
If oil accumulation is there then remove all fires and close air registers for cooling
before dropping
After dropping Fuel-gas/Hot well off gas burners/tips with face shield and asbestos gloves soak it in the soaking pit after cooling
Remove&replace damaged tips of the burners with new parts after checking condition if any, before assembling after cleaning
Fix Fuel-gas/Hot well off gas burners
Deblind Fuel-gas/Hot well off gas lines pilot gas lines.
Ensure no leaks then keep Fuel-gas/Hot well off gas fire ensuring pilot gas fire in
Finally, up-date burner spares register.&blind registers
13.21 Procedure for burners assembly dropping
During dropping and placing burner assembly keep stack damper wide position to
prevent excessive pressure developing in the furnace
Remove Fuel-gas/Hot well off gas fire&oil and pilot fires&blind them. also isolate air registers.
Disconnect pilot burner electrical power
Purge oil gun with steam for some time to prevent plugging with fuel-oil
purge steam valves are to be closed
Check burner in-side for oil accumulation through burner view ports
Use face shield and asbestos gloves during checking and dropping of burner assembly
Keep burner drain at assembly open to drain oil inside, if any.
After removing all fires&closing air registers allow the burner to cool for 2to3hrs. Disconnect oil&steam flexible hoses, drop oil gun
Drop Fuel-gas/pilot gas burners/tips with face shield and asbestos gloves soak it
in the soaking pit after cooling
Then drop the burner assembly for repairs&fix a plate at the bottom
Remove&replace damaged tips of the burners with new parts after checking condition if any, before assembling after cleaning
Fix burner assembly after repairs&after removing plate at the bottom after taking
clearances from INSPECTION/TSD.
Fix Fuel-gas/Hot well off gas/pilot burners.connect oil burner flexible hoses&oil
Deblind Fuel-gas/Hot well off gas lines pilot gas lines.
Ensure no leaks then keep Fuel-gas/Hot well off gas fire ensuring pilot gas fire in
side& adjusting air registers
Ensure no leaks for oil gun before placing oil fire.
Finally, up-date burner spares register.&blind registers Modifications
All product sample points are provided with block v/v&globe v/vs
All products individual lines to slop are provided with check v/s provision to
prevent contamination due slop back-up.
CBD pump is provided to trip on LOW discharge Pr in addition to trip on LOW
level to PROTECT the pump.
42v21 steam generator o/l shell v/v was removed as per boiler inspection
LEL detectors changing to INFRARED type
RADAR TYPE LTs are provided
Advanced process controllers are incorporated for optimizing products
quality&yields.
Vb naphtha to DHDS line was commissioned
Vb naphtha to FCCU-2 line hook-up is to be made.
Off-sites feed booster (vbu) 120pc2201 is incorporated on cdu-3/vbu panel.
13.22 Centrifugal pumps start-up:
Inspect whether all the mechanical jobs are over.
No load test of the motor during decoupling condition.
De-energize the motor for coupling with pump.
Establish bearing cooling water flow
Establish seal steam system.
Commission seals coolant systems to seals and check for leaks.
Check bearing housing oil level and check the oil content is free of
foreign material.
Rotate the shaft by hand for free movement.
Check the coupling guard intact or not.
Check the pump bay is clean and clear.
Check and remove all the foreign materials like cotton waste , used gaskets
And bolts lying in and around pump area.
Keep discharge valve and warm up valve in closed position. open suction
valve slightly and ensure that the casing is full of liquid by priming.
After wards keep the pump in warm up condition by opening warm up
valve slightly.
Check for leaks and open suction valve fully. Hot bolting of flanges are
to be done. Close the warm up valve.
Energize the motor and start the motor and check the pump direction ,
Rectify if the direction is incorrect.
Check the discharge pressure.
Open the discharge valve slowly while watch the discharge pressure
and Amps in the ammeter.
After steady state is attained check the flow ,temperature of the bearings
and vibration readings.
Check for gland\seal leaks for tightness.
CBD related blinds on pumps are to be blinded.
Shut down:
1. First close the discharge valve then only stops the pump. Then to keep warm up
2. Condition warm up valve is to be opened slightly.
3. If the pump is to be released for maintenance proceed as follows 4. Close suction warm-up and discharge valves.
5. Close seal oil systems to pump. 6. Keep the pump for cool down.
7. Flush the pump content to CBD after rebinding the concerned blinds. 8. Depressurize the pump for blinding.
9. Close cooling water to bearings. 10. Close seal steam system.
11. Open pump bleeder and check for passing of valves before handing over to maintenance for blinding.
12. Blind suction, Discharge, warm-up seal oil and seal steam systems.
13. Cut off electrical supply to pump motor before handing over to maintenance.
13.23 Trouble shooting problems:
A. Pump is not developing pressure due to improper priming or cavitation 1. Check bleed \vent pump casing.
2. Check the line up of the system \suction. 3. Check the suction strainer.
4. Check the level where the pump is taking suction. 5. Check pump coupling and pump rotation.
6. Check the temperature of the liquid. B. Unusual sounds
1. Check coupling guards.
2. Check pump, motor fan gland and motor guard. 3. Check for pump cavitation.
4. Get it further checked by rotary after stopping the pump. C. Raise of bearing temperature:
1. Improper lubrication due to low oil level
2. Insufficient bearing cooling water to bearing housing.
3. Stop the pump if the temperature is more than 75 0 C and inform to rotary to check
the pump and to do acid cleaning of BCW lines and bearing housing system. D. Unusual sounds:
1. Check the foundation bolts. 2. Check the fan cover for looseness. 3. Stop the pump to check alignment.
E. Leaky glands:
1. Check pumps discharge pressure. 2. Tighten the gland nut slowly if possible.
I (a) Pumps / Turbines seal repairs:
1. Isolate suction, discharge and warm up valves
2. Allow the system to cool down and then flush it with cutter to CBD through casing after removing blinds on cutter and CBD of the concerned.
3. After ensuring the stock becomes light depressurize it to CBD \OWS.Open pump vent \D\d PG point value for proper depressurizing.
4. Blinding is to be done for proper isolation on S\C,D\S,warm up ,flushing oil ,seal oil ,seal steam and CBD lines and update blinds register.
5. Isolate power to the pump.
6. Isolate steam to the turbine .If depressurize and blind it on steam side. 7. Issue permit, Decouple turbine \pump after ensuring the above. 8. Keep equipment under maintenance display board.
Note: disconnect instrument thermocouples as per rotary.
I (b) After the seal replacement on pump \ Turbine:
1. Check BCW, seal system, seal oil systems and remove any foreign materials in and around pump \turbine basements
2. Remove blinds on s\c, d\s ,warm up , CBD, seal systems, seal oil and flushing oil. Ensure proper gaskets are installed.
4. Open flushing oil slightly to fill casing and to remove air from D\S PG point. 5. Once oil is coming through D\S PG point close it. Also close casing drain to
CBD\ows and check pump blind flanges with FLO Pr (9 Kg\Cm2) for leaks.
6. Depressurize the cutter to OWS\CBD and open pump warm up valve slightly for warm up condition(only for hot service pumps).
7. Allow rotary to do hot alignment.
8. Allow maintenance to do hot bolting on blind flanges.
9. After hot alignment and coupling fixing, check for free movement of shaft. 10. Check no load before coupling as per rotary\Electrical and isolate power.
11. After ensuring all the jobs are over power to motor is to be released . Steam blind to turbine is to be removed.
12. Check the direction of the motor while placing the pump\Turbine.
13. When all the above factors are ok place the pump \Turbine and see the performance.
14. Keep casing drain to CBD\OWS blind.
15. Ensure updating of gaskets and blind registers.
16. Remove equipment under maintenance display board.
II (a) Pump \ Turbine suction strainers cleaning repeat steps 1,2,3,4,5,6 and 8.
(b) after pump\turbine suction strainers cleaned follow the steps 1,3,4,5,6,11,13,14,15 and 16.
III (a): LPG\ Naphtha pumps repairs:
1. Isolate suction, discharge and warm up valves 2. Isolate self-coolant lines.
3. Depressurize the content to flare through casing vent to flare. 4. Provide steam hose connection pump D\S PG point.
5. After ensuring gas is depressurized close casing vent to flare, Open casing drain to OWS and check if any gas is coming.
6. Observe passing of valves during depressuring to flare through of lines. 7. Ensuring system is depressurized blind S\C,D\S ,self coolant ,casing CBD\OWS
and flare systems ,update blind register.
8. Isolate power to the pump and disconnect steam hose. 9. Issue permit to rotary to carry out the seal replacement job. 10. Keep equipment under maintenance display board.
Note: Inform instrument people to check and repair seal pot pressure and low level switches if any.
III (B): When seal replacement job is over
1. Provide steam hose at pump D\S PG point. 2. Check self-coolant systems.
3. Check and remove all foreign materials in and around pump basement area. 4. Remove blinds on S\C ,D\S, self coolant systems.
5. Open steam and pressure test the pump for blinding flange leaks. 6. Close vents and bleeders.
7. During slight steam purge open suction valve and casing vent to flare for some time, and close steam completely.
8. Close casing vent to flare after some time. 9. Open casing drain to displace condensate if any. 10. Blind pump casing drain to OWS\CBD.
11. Check for no load test before fixing coupling as per rotary \ electrical. 12. When all jobs are over release power to motor and check direction of pump.
14. Ensure updation of blind and gasket registers.
15. Remove equipment under maintenance display board.
13.24 Depressurizing, Steaming and commissioning of coolers, condensers and exchangers for tube leaks:
1. Isolate inlet and outlet valves. On shell and tube and open bypass valve. 2. Depressurize the content to CBD\OWS after removing blind.
3. Cooling water is to be depress red to intermediate sewer.
4. Provide steam connection on shell side vent and start initial steaming.
5. After ensuring sweat steam and non passing of isolation valves stop steaming and blind both sides shell and tube inlet and outlet lines and update blind register. 6. Again carry out final steaming for 2 to 3 hrs then stop steam.
7. again put blinds.
8. Allow maintenance to carry tube leak jobs.
9. Care should be taken while bundle is pulled out and when fixing and dropping of components.
For exchanger :
1. Isolate I\L ,O\L,warm up valves,TSV’s on shell and tube sides and open bypass. 2. Steam connections are to be given to vents and depressurize to CBD\OWS on
both sides.
3. Ensuring sweat steam and non passing of isolation valves blind both shell and tube sides I\L and O\l.
4. Release exchanger for dropping components after closing steam valve. Disconnect it only after final steaming for 2 to 3 hours.
Commissioning of steam gens :
1. After the maintenance jobs are over connect steam hoses on shell and tube side
vents.
2. Deblind the shell and tube sides.
3. Steam test the blinding flanges at 5 to 6 Kg\Cm2.
4. When there is no leak deblind FLO and CBDblinds.
5. Cutter flush to CBD\OWS.
6. Remove all steam hoses and cap off vents.
7. Build up levels in steam gens and V21 up to 30 %.
8. Keep steam gen vents open.
9. After filling with cutter displace cutter to CBD\OWS with SR through top of the
bundle.
10. Ensuring cutter is displaced open I\L and O\L valves slightly keeping bypass in
wide open condition. Slowly open I\L and O\L valves and slowly close bypass of one steam gen.
11. Keep 42V21 warm up open.
12. Observe steam gen pressure and temperature and slowly open steam O\L valves.
13. Slowly close SR side bypass and steam gens one by one online.
14. Close local vent and keep the steam pressure control on system finally.
15. Check for leaks for flanges if any.
16. Blind CBD\OWS and FLO lines.
13.25 Hot well off gas routing to 42 F01 :
1. Check all hot well burners readiness.
2. Check the hot well off gas system from hot well to heater and flame arrestors. 3. Drain the liquid content at flame arrestor and catch pot.
4. Keep the hot well off gas plug cock in close position.
5. Reset hot well off gas SDV and check the system once again for leaks and free of liquid content.
6. During this activity one person at heater one person at hot well and one person at feed pumps PA has to coordinate with MOI person for effective operation .
7. Ensure the system is ok and light up pilots of hot well off gas burners and main gas fires before routing hot well off gas.
8. Keep one hot well off gas burner plug cock valve open and close hot well vent slowly.
9. Ensure hot well off gases are burning in the burner . Observe this flame then light up all four burners.
10. Slowly close the hot well vent and observe the flame pattern in the heater. 11. Finally check the system and vacuum of the column after routing.
13.26 ID fan placing : Field observation :
Check readiness of ID fan for lube oil level,motor,suction and discharge dampers openings, cooling water and circulating oil systems , foreign material removal and stack damper opening.
MOI observation :
1. Check whether the furnace arch temperature is >400 2. Keep fuel cutoff .
3. Keep ID fan fail bypass and interlocks in bypass mode. 4. start the fan from field.
5. Load the fan from PC5007 after resetting.
6. Observe the RPM, loading indication and check in the field about shaft movement.
7. Slowly increase the loading to increase the temperature of APH gradually.
8. Once the temperature of APH reached to the normal state ,then damper can be closed.
13.27 Introduction of bottom stripping steam to the columns(Atmos ans vac):
1. During the introduction of bottom stripping steam to the column ensure whether the shell valve , C\V,B\P and D\S isolation valves are closed or not.
2. Before introduction of steam drain the condensate from U\S and D\S bleeders of the C\V.
3. After ensuring that the system is condensate free open the C\V by 2 to 3 % and ensure dry steam from the drains.
4. Then Crack open the shell valve of the column.
5. Open shell valve and control valve gradually for the introduction of steam to the column.
6. Check whether oil is being backed up during this activity. 7. Slowly establish the steam flow.
8. Finally check for leaks.
Crude feed pump change over procedure:
1. First take clearance from CPP as it is a HT pump.
2. Check all the parameters like BCW, seal stream ,self coolant system ,suction valve opening and discharge valve closed position.
3. Check the pump basement for foreign materials removal. 4. Inform the field person to start the pump after CPP clearance.
5. Start the pump and adjust the discharge pressure around 27 Kg\Cm2 by opening
the discharge and simultaneously close the running pump discharge valve
gradually so that the discharge pressure PT1111 is maintained at 27 Kg\Cm2 , also
6. When the running pump discharge is fully closed and amps become lower side stop the feed pump after taking permission from control man in MOI.
7. check for leaks after changeover of pumps.
13.28 Crude feed booster pump change over procedure:
1. Check all the parameters like BCW, seal stream, self coolant system, suction valve opening and discharge valve closed position.
2. Ensure the discharge is fully closed and in warm up condition.
3. Close warm up after readiness of pump and motor, take out feed pass C\V from APC mode to operator mode.
4. Reduce Desalter pressure to 11.5 Kg\Cm2
5. Keep pass flow low low and Desalter low pressure trip in bypass mode during this activity.
6. Take clearance from CPP, as it is a HT pump.
7. Start the pump and adjust the discharge pressure around 32 to 34 Kg\Cm2 by
opening the discharge and simultaneously close the running pump discharge valve gradually so that the discharge pressure 42PT1112 is maintained at 11 to 12
Kg\Cm2, also watch the amps of the two pumps.
8. When the running pump discharge is fully closed and amps become Lower side stop the feed pump after taking permission from control man in MOI. 9. Check for leaks after changeover of pumps.
10. Keep the stand by booster pump warm up condition. 11. Place necessary trips online after the activity.
13.29 Power failure:
1. Open Atmos flare control valve bypass to control the top pressure by observing the 42V13 O\H pressure gauge.
2. Stop all pumps and take out all fires. 3. Bypass Desalter and close water injection. 4. Close all product rundown valves.
5. Stop all stripping steams to columns and product strippers, Vac ejectors steam and chemical injections.
6. Close V21 BFW shell valve.
7. Open hot well vent and close all hot well off gas valves to 42F01. 8. Bypass stabilizer and close LD CR to reboiler
Note: Check whether all related trip interlocks are activated or not during the emergency.
13.30 Fluid coupling oil coolers change over ;
Each fan is having two coolers for circulating oil. One is in online and other is stand by. If the online cooler performance is poor then the stand by is to be taken online to reduce circulating oil temperature.
The following steps are to be followed
1. Keep FD FAN A fail bypass , FD FAN B fail bypass FD FAN A\B fail bypass and interlocks PB5051,PB 5057 in bypass mode.
2. Combustion air fail PB 5053 in bypass. 3. Fuel cutoff in bypass(PB 5055)
4. Keep stack damper in open condition.
5. Then establish cooling water flow through stand by cooler by pinching down 3 way valve on inlet and outlet lines with out affecting flow to running fan.(observe 42FT5012).
6. Same way adjust circulating oil flow by watching the meter 42FT5010.
7. Adjust flows on water and oil and slowly close the flows through running cooler and increase stand by cooler. Finally establish flows through the stand by cooler. This way the fan does not get starvation of flows either on circulating oil or water side.
8. Then check the temperature physically and also observe leaks on the system. 9. Finally keep all trips in online position.
13.31 FD fan Change-over
Change over from FAN A to FAN B
Check list:
1. Check the running indication of both the fans and their discharge damper open indication.
2. On the hardware panel, check the discharge damper open / Close switch indication .The running fans switch should be in open state and the standby fans switch in closed state. In case of mismatch/Difference change the switch to match the same.
3. Check the stack damper opening % age (HS5006/5106) and whether it tallies with stack damper open indication. If not change HC value to 100 % irrespective of whether damper indication is there or not.
4. Put combustion air fail, Fan A fail, Fan B fail and Fan A/B fail hardware switches in bypass mode. This will bypass the interlock.
5. For both fans put air flow control in manual mode and change the selector switch (HS5001/5002) to hand control mode (HC5001, 5002) for fan loading.
6. After steps 1 to 5, Check all the parameters and in the hardware panel put heater in Turndown bypass mode ( Switch vertical to horizontal)
Note : In case the running fan A had also cut in at some earlier time, after putting in turndown bypass , all solenoids will get energized and both fans discharge dampers may close if the hardware switch is not in open condition.
To do:
1. After putting in turndown bypass, reduce standby fanB loading to 2-5 % 2. Start the standby fan in field
3. Reset fan B loading and open discharge damper of fan B.
4. Increase fan B loading in gradual steps of 2 % and reduce fan A loading in a similar fashion. this might result in internal circulation of air and momentary low combustion air to furnace.
5. Slowly go up on fan B loading to restore normal air flow and continue to reduce fan A loading. Continue till fan B has taken full load.
6. Close fan A discharge damper after reducing fan loading to minimum. If all in OK stop fan A from hardware panel.
8. Put all the trips online. Fan A fail in bypass state and Fan B fail in online state. Fan a/B fail should also be bypassed. Combustion air fail in online position. 9. In the end put turndown in activation mode (Vertical switch)
Note: During entire operation stack damper open indication should be there and damper opening (HC value) should be 100%.
For opening stack damper always use software switch in the DCS. Operate Hard ware switch only during emergency.
