Post on 03-Jan-2016
description
transcript
Submitted To: Mr. Shehzad Ahmad Khan Group Head (Process Maintenance)
Submitted By: M. Sohaib Ur Rehman Trainee Engineer Mechanical P # 5518
REPORT MAINTENANCE PROCESS (MECH)
1. PROCESS MAITNENANCE
1.1. PROCESS AREA 100, 200, 300
The maintenance of rotary as well as stationary equipments and accessories related to mechanical comes under the scope of Process Maintenance. Satellite Workshop 1 is present near process area to do daily kind of emergencies that occur in these areas.
Area 100: Unit 100 (Crude Distillation Unit), Un
Area 200: Unit 130 (VBU), Unit 411 (GCU)
Area 300: Unit 284 (Diesel Max)
1.2. PROCESS AREA 400, 500, 600
Satellite workshop 2 manpower is responsible for doing all daily jobs and handling emergencies that can occur in these areas.
Area 400: Unit 200 (NHT), Unit 300 (PLAT), Unit 312 (CCR)
Area 500: Unit 801(KMRX), Unit 802 (CMRX), Unit 810 (ATU)
Area 600: Unit 820 (SRU)
1.3. DHDS UNIT 1010
Maintenance satellite workshomaintenance activities on DHDS unit.
PROCESS MAINTENANCE
SATELLITE WORKSHOP 1:
AREA 100AREA 200AREA 300
SATELLITE WORKSHOP 2:
MAINTENANCE PROCESS
MAITNENANCE SECTION
PROCESS AREA 100, 200, 300
The maintenance of rotary as well as stationary equipments and accessories related to mechanical comes under the scope of Process Maintenance. Satellite Workshop 1 is present near process area to do daily maintenance jobs along with handling any kind of emergencies that occur in these areas.
Unit 100 (Crude Distillation Unit), Unit 110 (Vacuum Distillation Unit)
Unit 130 (VBU), Unit 411 (GCU)
Unit 284 (Diesel Max)
400, 500, 600
Satellite workshop 2 manpower is responsible for doing all daily jobs and handling emergencies that can occur in these areas.
Unit 200 (NHT), Unit 300 (PLAT), Unit 312 (CCR)
Unit 801(KMRX), Unit 802 (CMRX), Unit 810 (ATU)
Maintenance satellite workshop 3 is present in DHDS area for doingmaintenance activities on DHDS unit.
PROCESS MAINTENANCE
SATELLITE WORKSHOP 2:
AREA 400AREA 500AREA 600
SATELLITE WORKSHOP 3:
DHDS UNIT 1010
MAINTENANCE PROCESS
2 | P a g e
The maintenance of rotary as well as stationary equipments and accessories related to mechanical comes under the scope of Process Maintenance. Satellite Workshop 1
maintenance jobs along with handling any
uum Distillation Unit)
Satellite workshop 2 manpower is responsible for doing all daily jobs and handling
p 3 is present in DHDS area for doing different
WORKSHOP 3:
DHDS UNIT 1010
MAINTENANCE PROCESS
3 | P a g e
2. MAINTENANCE ACTIVITIES WITNESSED
JOB # 1: Preventive maintenance of AFC 100-EA4C4
AFC FANSAn Air Cooled Heat Exchanger (or Air Fin Cooler) is a device for rejecting heat from a fluid directly to ambient air.
AFC Fans blades can be: 1. Fixed Pitch Blades2. Adjustable pitch blades
Except for small diameters (less than 5 feet), most AFCs have adjustable pitch blades. Adjustable pitch fans are manufactured in two types:
2.1. Manually adjustable or AP (when the fan is off)2.2. Automatically variation or AV (when the fan is running)
Most automatically adjustable pitch fans change their pitch by means of apneumatically-actuated diaphragm working against large springs inside the hub.There are numerous numbers of AFC fans installed in PARCO which are adjustable pitch (AP) and Automatic Variation (AV). The 100-EA4C4 AFC cooler is forced draft manually adjustable pitch (AP) fan.
Preventive Maintenance activity was done on manually adjustable pitch fan after 6 months.
MAINTENANCE PROCESS
4 | P a g e
WORK PERMITS TAKEN: Cold work permit, Electrical isolation/de-isolation permit
MANPOWER INVOLVED:1 millwright, 1 fitter, 1 helper
ACTIVITY DURATION: 3 hours
PM ACTIVITY:
Scaffolding at the work site was done to perform the maintenance activity. After electrical and mechanical isolation of the fan, the AFC window was
unbolted. Greasing of bearings was done after unbolting of window. Belt of AFC was removed from bull gear and motor gear. Belt condition was checked and found ok. Blade clearance from wall and blade angle readings were noted down for all
the 8 blades which are:
Sr. No.
AFC Blade Blade angle Tip clearance (mm)
1. 1st12.5
o 16
2. 2nd12.5
o 16
3. 3rd12.5
o 16
4. 4th12.5
o 17
5. 5th12.5
o 15
6. 6th12.5
o 16
7. 7th12.5
o 17
8. 8th12.5
o 18
The blade angle and tip clearances were found within allowable range. AFC fan was cleaned with a jet of steam and water. Its parts were cleaned thoroughly. Belt of AFC fan was cleaned and fitted back to its position. AFC windows were fitted and other checks were done Housekeeping of the work site was done. AFC was re-commissioned and handed over to operations. Work permit was closed.
MAINTENANCE PROCESS
5 | P a g e
JOB # 2: To change the lube oil of steam turbine driving lube oil pump of 411-C1 compressor.
411-C1 COMPRESSOR
MANUFACTURER: Hitachi
This centrifugal compressor is 2 stage with balanced opposed rotor assembly. This compressor is handling Hydrogen and hydrocarbons so it is called wet gas compressor. 411-C1 is driven by steam turbine which is manufactured by SHIN NIPPON. Its power is 1102 KW and speed is 11800 rpm.Forced feed lubrication of compressor is done by 2 screw pumps handling lube oil. 1 pump is driven by steam turbine and 1 pump is motor driven. Lube oil replacement activity of screw pump and Coppus turbine was done.
WORK PERMITS TAKEN: Cold work permit, Electrical isolation/de-isolation permit
MANPOWER INVOLVED:1 millwright, 1 fitter, 1 helper
ACTIVITY DURATION: 2 hours
MAINTENANCE ACTIVITY:
Work Permit was obtained by maintenance team from operations personnel. Steam turbine driven lube oil pump was shut down and standby pump was
started. After giving some time to cool down the steam turbine, all inlet and outlet
valves were closed and turbine was electrically isolated. Lube oil of turbine inboard side was drained and bearing housing was flushed
with clean oil by opening drain port. Drain port of bearing housing was closed and lube oil level was maintained. Oil leveler was also cleaned and lube oil was filled to a specific level. Lube oil of turbine outboard side was also replaced by repeating the same
steps. Lube oil of turbine mechanical governor was replaced after draining the lube
oil present in it and cleaning with new oil. After lube oil replacement, turbine and pump was cleaned with water
showering. Housekeeping of the area was done and handed over to operations. Electrical de-isolation was done Turbine was re-commissioned and all parameters were found ok. Work permit closed.
MAINTENANCE PROCESS
6 | P a g e
JOB # 3: To clean the strainer of 100-P10B.
STRAINERSIn steam and condensate systems, damage to plant is frequently caused by pipeline debris such as scale, rust, jointing compound, weld metal and other solids, which may find their way into the pipeline system. Strainers are devices which arrest these solids in flowing liquids or gases, and protect equipment from their harmful effects, thus reducing downtime and maintenance. A strainer should be fitted upstream of every steam trap, flowmeter and control valve.
TYPES OF STRAINERS:1. Y TYPE
Y Type strainer body has a compact cylindrical shape that is very strong and can handle high pressures. It is literally a pressure vessel, and it is not uncommon for Y-type strainers to be able to handle pressures of up to 400 bar g. Y-type strainers have a lower dirt holding capacity than basket strainers, which means that they require more frequent cleaning.
2. BASKET TYPEIt is a vertically orientated chamber, typically larger than that of a Y-type strainer. It has a greater free straining area, which makes the basket type strainer the preferred type for liquid applications. As the dirt holding capacity is also greater than in Y-type strainers, the basket type strainer is also used on larger diameter steam pipelines.
WORK PERMITS TAKEN: Cold work permit, Electrical isolation permit
RESOURCES INVOLVED:Tools, cotton gloves, cotton cloth
MANPOWER INVOLVED:1 supervisor, 1 fitter, 1 helper
ACTIVITY DURATION: 2 hours
STRAINER TYPE: Basket type strainer
MAINTENANCE PROCESS
7 | P a g e
MAINTENANCE ACTIVITY:
Cold work permit was obtained from operation personal. Bolts of bucket type strainer side flange were opened to remove strainer
inside the bucket. Strainer was removed. Strainer was shifted to ground from strainer platform. Cleaning of strainer was done with water and sludge was removed. Huge amount of sludge was present inside the strainer so its cleaning was
done in different steps.- Cleaning of strainer mesh was done LS steam.- Then strainer was cleaned with water from hose pipe and then with
steam again. Strainer was installed back to its position. New gasket was placed and the flange bolts were tightened. After completion of maintenance activity, housekeeping was done. Pump was re-commissioned and the pressure difference across strainer was
found within allowable limit. Work permit was handed over to operations and permit was closed.
JOB # 4: To replace the mechanical seal of 110-P4B.
MECHANICAL SEAL
A mechanical seal is installed in centrifugal pumps to prevent leakage of fluid from casing into the atmosphere. A mechanical seal has following parts.
1. A set of primary seal faces: one rotary and one stationary as seal ring and insert.
2. A set of secondary seals known as shaft packings and insert mountings such as 0-rings, wedges and V-rings.
3. Mechanical seal hardware including gland rings, collars, compression rings, pins, springs and bellows.
MAINTENANCE PROCESS
8 | P a g e
PROBLEM:Mechanical seal of 110-P4B was found leaking more than the allowable range.
So it was planned to replace the mechanical seal of this pump.
WORK PERMITS TAKEN: Cold work permit, Electrical isolation/de-isolation permit
RESOURCES INVOLVED:Tools, cotton gloves, cotton cloth, chain block,
MANPOWER INVOLVED: 1 supervisor, 3 technician, 2 helper
ACTIVITY DURATION: 7 hours
MECHANICAL SEAL TYPE: Pusher type, multi spring, single cartridge seal.
MAINTENANCE ACTIVITY:
Local switch of motor was log out, tag out. Blinding was done at pump’s suction and discharge valves. Pump was depressurized / drained. Work permit was obtained from operation personal. Coupling was removed. DBSE (Distance Between Shaft Ends) was checked and it was noted down. Check lube oil for contamination. Pumps casing bolt loosened. Pump impeller and bearing housing was separated from pump’s volute
casing. Pump assembly was lifted via chain block and shifted to ground. Impeller lock nut removed. Impeller washer removed. Impeller was removed from shaft. Wear rings condition was checked along with clearances. Bearing housing dismantled by opening bolts.
Mechanical seal was removed.
CLEANING & ASSEMBLY PHASE:
Cleaning of shaft was done with water and emery paper. Cleaning of pump was done with plant water. New cartridge type mechanical seal was mounted on shaft. Bearing housing assembly done with shaft and bolts tightened. Pump impeller was mounted and impeller lock nut tightened.
MAINTENANCE PROCESS
9 | P a g e
Pump parts were shifted to its place for assembly in casing. Pump was assembled in its casing and bolts tightened. Fill lube oil in bearing housing and maintain level in oil cup. Install coupling hub and couple the pump. Rim and face alignment was performed and motor side was adjusted by
putting shims under its foot to align the pump shaft and motor shaft. After doing alignment activity, housekeeping was performed. Pump was re-commissioned and checked for leakage from seal and
abnormal sound. No leakage was found and abnormal sound observed. Work permit was closed.
JOB # 5: To grease the bearings of rotoform of Sulpher Solidification unit SSU belt 820 – ME80 A/B.
SSU (Sulfur Solidification Unit) & ROTOFORM
Sulfur Solidification facility consists of two SANDVIK solidification machines (820-ME80A/B). Liquid sulfur is fed to these machines through a feed pipe and rotoform sprays this molten sulfur onto the drum. Rotoform is a cylindrical pipe with ball bearings at its both ends. Molten sulfur is solidified by spraying water below the SS belt and it is scraped off at the end by a knife.
WORK PERMITS TAKEN: Cold work permit
RESOURCES INVOLVED:Grease gun, shell 16 grease, cotton gloves, cotton cloth.
MAINTENANCE PROCESS
10 | P a g e
MANPOWER INVOLVED:1 technician, 1 fitter
ACTIVITY DURATION: 1 hour
ACTIVITY:
Cold work permit was obtained from operations personnel. Grease was loaded in the grease gun. After loading grease, rotoform bearing grease cap was opened. Grease was loaded into the bearings until it drains from the drain point. Cleaning of bearings done. Greasing of rotoform left side and right side bearing done in the same way. Grease was loaded in the grease gun and grease inserted in the rotoform of
820- ME80B in the same manner. Housekeeping was done after activity. Work permit was closed.
JOB # 6: To back flush seal cooler of 300-P5B due to increased temperature upto 70 degrees.
MECHANICAL SEAL API PLAN
To cool the flushing liquid inside the mechanical seal, API Plan 21 takes service liquid from the discharge of pump and it goes to seal oil cooler where it is cooled by plant water and flushing fluid after cooling comes to the mechanical seal flush port.Due to contamination present in the plant water, scaling occurs on seal cooler and it is blocked and discharge temperature to mechanical seal increases. Thus back flushing of seal cooler and sometimes cleaning is done when temperature reaches to 100 degrees.
WORK PERMITS TAKEN: Cold work permit
RESOURCES INVOLVED:Brass hammer, cotton gloves.
MANPOWER INVOLVED: 1 technician, 1 fitter, 1 helper
ACTIVITY DURATION: 0.5 hour
MAINTENANCE PROCESS
11 | P a g e
ACTIVITY:
Cold work permit obtained from operations personnel. Pump was in running condition and activity was performed. Back flush water line of seal cooler was opened. Seal cooler was hammered with brass hammer to de-block any slurry
material present in the seal cooler shell. Cooling water supply line opened. Flushing of CWS line was done. Hammering of seal cooler was done along with flushing. Mechanical seal flush line discharge temperature from seal cooler decreased
to some degrees.
OBSERVATION: Seal cooler scaling is caused due to contaminants present in cooling water
and it decreases the heat transfer efficiency which can damage the mechanical seal due to high temperatures within the seal. For in service rectification of scaling inside the seal cooler, some chemical should be used for removal of contaminants inside seal cooler.
JOB # 7: Apply Jaddi compound on lift 820-ME5.
PROBLEM: A lift is present in the process area. Its railings lubrication is done by applying Jaddi Compound with the help of rollers along the whole height of lift.
RESOURCES INVOLVED:Coating rollers, Jaddi compound, cotton gloves and cloth.
MANPOWER INVOLVED: 1 technician, 2 fitter, 1 helper
ACTIVITY DURATION: 1 hour
ACTIVITY:
Manpower and necessary resources for the job reached the lift. After getting into the lift, lift was started and 2 persons simultaneously applied
Jaddi compound with the help of rollers on 2 railings of lift. Jaddi compound was applied on the whole length of lift and similarly on the
left hand side of lift.
MAINTENANCE PROCESS
12 | P a g e
OBSERVATIONS & SUGGESTIONS
1. Maintenance personnel should consider RCM (Reliability Centered Maintenance) techniques to increase the reliability of equipments and to reduce the maintenance costs. As RCM identifies the operating context of the machinery, and writes a Failure Mode Effects and Criticality Analysis (FMECA) which helps in monitoring, assessing and predicting the working of machineries.
2. Training of maintenance staff related to Plant Maintenance new techniques should be a high priority to make the staff trained enough for handling any kind of emergencies with high-level management oversight.
3. Special assignments should be done to identify parts that can be indigenized in house to reduce the spare parts cost.