Thursday, May 27, 2010

Week 8, 26th May

Abang Nasir, peronda, brings me to fire fighting pump house to check the availability of the pump. He explained that if pressure is less than 9 bar, jockey pump is activated while less than 7 bar, electric pump is on. Diesel pump 1 will activate when pressure less than 5 bar and diesel 2 will activate when pressure less than 4 bar.

The procedure of doing the checking is opened the bypass valve to let the water flowing back to water tank. Then manually turn on the electric pump, follow by diesel 1 pump and diesel 2 pump. Reading of discharge pressure and flow of water were taken. After all the reading had taken, the bypass valve is closed and all the pumps were set back to automatic mode.

Week 8, 25th May

I followed abang Suhaimi, block operator, to do the pump changeover at STG. The pumps that need to do the changeover are demin water transfer pump, closed cycle circulating water pump, service water pump, condenser extraction pump, gland steam condenser exhauster, hydraulic pump, lube oil pump and seawater booster pump.

This activity will be done weekly so that the pump can extend its working period. The main reason is to test the standby pump availability so that when in emergency, it is still functional.

Week 8, 24th May

I will be in the operation section for the next three weeks. As I just joined the operation section, abang Fadli, senior block operator, explained to me the importance of the operation section as they monitor the plant’s operation.

At around 11am, steam turbine trip suddenly due to loss of instrument pressure. Abang Halim, shift charge engineer (SCE), informed National Load Dispatch Center (NLDC) due to full block trip. Then, he informed ECNI technician to identify the problem. After checking the tube of instrument air that found no leaking, they focus on the air compressor. It is found that the instrument air compressor 1B air separator broken.

After identify the problem, the start up of GT1 begin then ST and GT2. At around 5pm, the SCE declare to NLDC that load back to maximum that is 322MW.

The instrument air compressor 1B that make the steam turbine tripped due to loss of pressure

Wednesday, May 26, 2010

outage, 15th May

The outage started from 12am Saturday. All the preparation had been done and the operation team had get permission from NLDC (National Load Dispatch Center) prior shutdown.

After shutdown, the maintenance outage is started. The preventative maintenance that I followed were carbon brush inspection, field breaker maintenance, 52G inspection, exciter inspection, interposing relay panel inspection, protection relay inspection and testing of all DC motors for GT1 , GT2 and ST. as the time is limited, a;; the inspection need to finish it as soon as possible.

For the corrective maintenance, abang Fadzli and abang Razak changed the defect contactor for circulating water pump panel box.

For the plant improvement, the plant had hired the contractor to upgrade the primary injection of 190 feeder PT and CT and the overcurrent and earth fault relays for station board 2. These works are all included in electrical section works.

For the mechanical parts, I participated in the circulating water pump rotary drum screen pit preventative maintenance. A stop block pathway is put to prevent the seawater flow into the drum screen pit. The cleaning process begins with pull up the primary drum screen and cleans it. Then the pit contractor will climb down the pit to clean up the trashes that sink in the pit.

A dry type transformer

A rectifier

Week 7, 21st May

After finish repair the shaft, connection between the sleeve bearings is screw and the new shaft is being installed. The spacers that installed at the top of the shaft then are coupled with the motor. After all the work had done, we installed the pump back to the water treatment plant there.

Abang Yunizar do the final touching up and examination
before installing the pump back at water treatment plant

Week 7, 20th May

Today the work is continuing with the transfer pump yesterday. A new shaft is being replaced and the cleaning of the pump is done.

Week7, 19th May

At the water treatment plant, the chemical waste pump is found faulty. I followed abang Syahrul to check the pump. The pump motor is in good condition; hence the problem mostly is the shaft. After dissemble the pump, we found out that the connection of the shaft and impeller broken.

In the evening, there is a farewell party for our plant station manager, Mr. Chew, as he is going oversea on June for working purpose.

The pump is lift up to do the checking

Week 7, 18th May

I and other 2 trainees, Zul and Saw had been ordered by En. Rahimi to follow abang Munir to do the general air service compressor preventative maintenance. We check the air filter, lube oil filter and refill the lube oil as the running hour for the compressor had reached the limit.

Then, abang Munir explained to us that the function of the service air and instrument air and their differences. He also explained the flow of how dry, oil-free compressed air is produce.

The service air system provides compressed air at the required pressure and capacity for general plant use and as a backup supply to the instrument air system while instrument air system provides dry compressed air at the required pressure and capacity for all pneumatic valves, controls, transmitters, and instrument.

The flow of compressed service air

Week 7, 17th May

Today work is about corrective maintenance. At the water treatment plant, the demineralized recycle pump 2A is found leaking. I followed abang Ramli to do the checking and rectify it.

In the evening, all the technicians do the cleaning at the workshop as the outage had finished.

Week 6, 14th May

I followed abang Yunizar to go to the loading bay to take submersible pump. The pump is used to pump the water out from drum screen pit during the outage.

Then all the following works today are just preparation for the outage.

The equipment that need to use during the outage

Week 6, 13rd May

Boiler feed pump control valve pipe is found leak. To solve the leakage problem, welding is done by En. Ramli. Then, to detect whether there is still leakage, dye penetration equipment is used. If there is leakage, the red colour will show at leakage part.

En. Rahimi doing the welding for boiler feed pump control valve pipe

For other technicians, they were busy preparing the equipment that need to use during the outage that is on Saturday.


Week 6, 12th May

This morning, I followed abang Yunizar to the rotary screen area to do the circulating water rotary screen trash basket maintenance inspection. All of us came to help the cleaning.

The contractors are cleaning the primary drum screen

En. Rahimi explained to us the alignment and its function. It is about finding the rotational center of motor and positioning of the motor. The symptoms of misalignment are high discharge of temperature, vibrate or loosen of the foundation bolts and etc. The causes of misalignment are bent shaft, soft foot and etc.

To show us in the more practical way, En. Rahimi brought an old pump to workshop for alignment demonstration. Laser alignment device is used to detect the state of accuracy of the alignment

En. Rahimi demonstrate how to measure the alignment

Week 6, 11st May

I was assigned to follow abang Yunizar, technician of mechanical section, to do the PM for service water pump discharged NRV. To increase the efficiency of the motor, maintenance need to do frequently.

Then for the part of the valve, we opened it and do the cleaning as there are a lot of rusted layers in the valve. After finish the cleaning, abang Yunizar then changed the motor oil to let the motor run smoothly.

Abang Yunizar is changing the motor oil

Week 6, 10th May

For the next two weeks, I will be joining the mechanical section. After meet with En. Amir, mechanical engineer, he explained to me roughly the staff in mechanical section and then En. Rahimi, mechanical supervisor, asked me to meet him at the workshop. He told me that the operation of the mechanical section.

The PM that I followed is HRSG blowdown transfer pump. The function of the transfer pump is transferring the demineralized water to water treatment system. Most of the work is about corrosion. The corrosion layers were scraped and the whole exterior of transfer pump was painted with anti-rust paint.

The worker take out the transfer pump using forklift

The exterior of transfer pump was painted with anti-rust paint

Week 5, 7th May

I followed Mr. Tai to do the CCTV inspection PM. We need to check from the control center room to see whether all the function is ok. If the screen is blurring, we need to note down the number of CCTV and clean it later.

After finish the PM, all the CNI technician went to the boiler building to install the motorized actuator.

Abang Azim is installing the motorized actuator at boiler drum

Week 5, 6th May

The PM that I did today almost same with yesterday, that is HRSG2 Siemens CEMS inspection.

Then, abang Syahrul and abang Azim explained briefly about bailey infinet and termination unit in the network system of the power plant. Every process control unit (PCU) will connect to a single termination unit (TU) and send to redundant/bailey infinet communication system. The information then will send to the operator interface station (OIS) to let the operator to control the final control element (open or close, start or stop). For amending the program of the PCU, the programmer can go to the management command system (MSC) or engineering work station (EWS).

The network system of the power plant

Week 5, 5th May

The plant has the force outage as the HP feedwater NRV is not functioning. The valve needs to be open to let the HP feedwater flow from boiler feedwater pump but the valve is jammed. Hence, the mechanical technician use hydraulic jet to force the valve open and repair will be done during the outage.

In the evening, I followed abang Syahrul to do the HRSG1 Siemens Continuous emission monitoring system (CEMS) inspection. We need to check the lamp, switch, indication bulbs whether it is function or not. Then, we need to take the measurement for UTM120 and UTM130 device for the flow rate and percentage of oxygen.


Abang Syahrul explained the CEMS to us on how it works

Week 5, 4th May

The preventative maintenance that I followed today is Bailey Infi90 power supply monthly inspection. I and Mr. Tai need to check the indication lamp and voltage measurement. If the indication lamp is green, the device is fine. If the indication lamp is red, the device needs to repair. For the voltage measurement, we need to note down the voltage of +15V, -15V, 48V, 24V and 5V for each connection in the PCU power supply.

In the evening, En. Sharif asked me to help the electrical section to wash the motor of the air compressor. I used the chemical (synthetic isoporaffinic hydrocarbon) to clean the stains on the shaft of the motor.

The technicains clean the stains on the motor

Week 5, 3rd May

En. Yunus, CNI supervisor, asked me to follow abang Azim to do the corrective maintenance as the air dryer system at the EDG house need to install a new air drain device. The process of installing the air drain device take time as all the precaution step need to be checked before the work start.

In the evening, Sri Daran gave us a set of basic electrical test. Our result will know after he finish marking the paper.

Air drain device

Sunday, May 9, 2010

Week 4, 30th April

In the morning, I followed abang Azim to do the Gas Chromatography (NGC) monthly inspection and calibration preventative maintenance. There are 4 parts in this inspection, which is visual inspection, current measurement, calibration procedure and calibration result.

For the visual inspection, we need to check the cleanliness and physical connection of tubing and cables.
For the current measurement status, we need to note down the sample pressure, un-normalized value and superior (dry) current value.
For the calibration process, manually run STREAM 4 and STREAM 1. Then view the chromatography for STREAM 4. There are 7 peak values for chrom-1 and 5 peak values for chrom-2.
For the calibration result on STREAM 4, we need to note down all the components value in the gas. The components are ethane, propane, carbon dioxide, methane and etc.

In the evening, all of the staffs required to attend the knowledge sharing session. En. Azizul, IT executive, provide a talk about the new ICT password policy. It is stated that the password must be changed after 6 months or 180 days of usage. Then, it is the turn for En. Sharif, supervisor for electrical department, gives a talk about steam turbine power distribution system.

Week 4, 29th April

The PM that needs to do today is GT 1&2 local temperature gauge inspection. The procedure is almost same with the PM that had done yesterday.

In the evening, I was given an assignment by Sri Daran. I need to find out the ANSI code for the protection relay that used in the plant. ANSI stand for America National Standard Institution that provide the code for all the protection relay.

Week 4, 28th April

Today, I followed abang Syahrul to do the HRSG 1&2 local pressure gauge inspection. We were required to take the reading and check for the defects. After finish taking the reading, we found out that blowdown transfer pump 7 pressure gauge is defect. As there is no pressure gauge for range 0-4 bars, replacement will be made when the order arrived.

Abang Azim then explained to me the type of pressure gauge that we used in the plant and its function. The C-type bourden tube pressure tube is used for measuring pressure difference. Then he also explained to me the difference between the gauge pressure, absolute pressure and atmospheric pressure.

C-type bourden tube

Week 4, 27th April

The preventative maintenance that I participated in is steam turbine generator and heat recovery steam generator (HRSG) 1&2 motorized actuators inspection. We need to check the feedback availability whether it is close or open and check for the defects.

The actuators that used in the plant mostly is limitorque L120 series actuators. It can be used to control butterfly, ball, and plug valves which requires 90 degrees movement.

motorized actuator

Week 4, 26th April

The 2 PMs that required to do are fire fighting tank and distillate tank transmitter inspection and turbine flow meter inspection. This is the first job I participated in for control and instrumentation section.

For the fire fighting tank and distillate tank transmitter inspection, I followed Mr. Tai, CNI technician, to take the reading for fire tank A and B from the level transmitter. Same process applied to the distillate tank.

For the turbine flow meter inspection, I followed abang Syahrul to take the flow meter reading for steam turbine. Besides that, we also checked whether it need for lubrication or not.

During the free time, Mr. Tai explained to me that AT-1000 series transmitter is designed to attach to the LT-LTC series level gauge. One of its main function is to convert the level gauge’s signal into voltage and electric current to perform tank inventory management.

AT 1000 series transmitter that attach to the LT-LTC series level gauge