Operating & Maintenance Procedure for Air Cooler Heat Exchanger

DYNAC ENGINEERING SDN. BHD.

Cendor Phase 2 FPSO Operating & Maintenance Procedure

Doc. No.: 100-8137-00-ME-PRO-0022 Page No. :

Rev.: R1 2 of 10

Table of Content 1.0 2.0 3.0 4.0

Scope .................................................................................................................................................. 3 References ......................................................................................................................................... 3 Operating Procedure ......................................................................................................................... 4 Maintenance Procedure .................................................................................................................... 6

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SCOPE This procedure covers the steps for site commissioning, operation and maintenance of an Air-Cooled Heat Exchangers (ACHE) for Cendor Phase 2 FPSO Project.

2.0

•

One (1) unit of Crude Rundown Cooler (Equipment No: E-3601)

•

One (1) unit of Hot Oil Dump Cooler (Equipment No: E-4101)

•

Two (2) units of 1st Stage Discharge Cooler (Equipment No: A-2001-E-01/A-2002-E01)

•

Two (2) units of 2nd Stage Discharge Cooler (Equipment No: A-2001-E-02/A-2002-E02)

•

Two (2) units of Gas Lift/ Reinjection Inlet Cooler ( Equipment No: A-2001-E-03/A2002-E-03)

REFERENCES 2.1

General Specification for Air Cooled Heat Exchangers – CP2-0000-00-ME-SPE-0002

2.2

ASME Boiler & Pressure Vessel Code, Section VIII Division 1

2.3

ASME Boiler & Pressure Vessel Code, Section VIII Division 2 (For Inspection and Material Requirement).

2.4

ISO 13706-1;2005, (Identical) Petroleum, Petrochemical and Natural Gas Industries – Air-Cooled Heat Exchangers

2.5

PTS 61.10.08.11-Gen. – Field Inspection Prior to Commissioning of Mechanical Equipment

2.6

PTS 70.10.80.11 – Cleaning of Equipment

2.7

Project AFM Drawing

2.8

Shop Run Test Procedure, 100-8137-00-ME-PRO-0019

2.9

Motor Data Sheet, 100-8137-36-EL-DTS-0001~0005

2.10

Fan Data Sheet, 100-8137-36-ME-DTS-0006~0010

2.11

Fan Drive Data Sheet, 100-8137-36-ME-DTS-0012~0016

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OPERATING PROCEDURE Although fan and drive assembly are inspected or tested at shop before shipment, the following should be checked to ensure that rough handling during shipment has not loosened the bearing mounting bolts, which may caused misalignment. 3.1

Prior to Start-Up A. Drive Assembly 1.

Check fan shaft bearing mounting bolts and its lubrication.

2.

Check free rotation for fan and motor.

3.

Check tightness of motor and fan pulley.

4.

Check belt tension and alignment (this item should be checked again few days after start-up). Refer Fan Drive Data Sheet 100-8137-36-ME-DTS0012~0016 for detail.

B. Fan 1.

Check all bolts and set screws on fan hub and taper lock bushing to ensure they are properly tightened.

2.

Manually rotate fan to check clearance between blades and fan ring and fan guard.

3.

Ensure the fan guard is in place prior to start up. C. Tube Bundle / Structure

1.

All respective process fluid inlet and outlet nozzles are connected properly and correctly.

2.

All drain and vent nozzles are to be opened and closed in accordance to system requirement.

3.

Remove temporary shipping clip if provided.

4.

Remove all shipment cover and its tie downs if attached.

5.

Check fan deck and drive assembly area to ensure all tools, bolts and nuts and other construction materials are removed.

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Check all bolts and nuts on the structure/bracing of the unit to ensure they are properly tightened. D. Vibration Switch

3.2

1.

Ensure vibration switch are securely fasten prior to start up.

2.

Ensure termination cover for the vibration switch is properly closed.

Start-Up A. Drive Assembly 1.

Start fan and check direction of rotation (being anti-clockwise if viewed from under the fan).

2.

Run the fan for approximately 10 minutes.

3.

Check motor running ampere reading against rated ampere. Running ampere shall be lower than rated ampere under normal conditions.

4.

Check for excessive and abnormal noise and vibration.

5.

Stop the fan after running for approximately 30 minutes for observing the fan as it come to resting position.

6.

Run the fan for a couple of hours to ensure proper and correct operation.

7.

Check bearings for abnormal temperature. Normal temperature may range from cool to warm to touch showing adequate grease. Too hot to touch for a few seconds showing inadequate grease and noisy. B. Introduction of Process Fluid

1.

Open inlet valve slowly and let the process flow through and “warm” the bundles slowly to prevent and minimize thermal shock.

2.

Extra specific precautions should be observed when handling lethal or hazardous fluid.

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MAINTENANCE PROCEDURE 4.1

TUBE CLEANING 1

The most common and cost effective way to cleaning of external fin by directing compressed air on fin surfaces or apply hydrochloric acid 5% by weight and followed by water spray through the fin from the opposite direction of operation air flow.

2

Internal cleaning of tube i) Mechanical Cleaning – This method consist of utilizing drill head or wire brush with universal joint attached to a long metal rod. The metal rod is rotated with an air or electrical tool or motor and flushing with water to clear the fouling material. Compressed air is use to purge dry after the cleaning process. This method of cleaning is not recommended for “Tarry” fouling materials. ii) Chemical Cleaning – This method of cleaning involves introducing concentrated hydrochloric acid or sulphuric acid through the tubes until required concentration is reached, this is usually 2% to 5% by weight for hydrochloric acid and 4% to 10% by weight for sulphuric acid. Acid concentration shall be checked regularly, maintaining the strength by adding fresh acid. Neutralisation shall be carried out by introducing a mixture of water and caustic soda into the tube, until 1% to 2% by weight alkaline solution is obtained. iii) High Pressure Water Spray – The use of high pressure water spray or “Hydro Jet” cleaning is also a popular for use in cleaning the tube internal surface of tube bundle. The high pressure jet is in place on the end of a hollow rod. Similar to the method used in mechanical cleaning, the rod is push through every tubes of tube bundle to clean it. The effective water jet pressure is determined through trial cleaning. Usually softer fouling deposits require lower jet pressure. Note: Water used for cleaning shall meet chloride content of 250 ppm as per PTS 61.10.08.11-Gen

4.2

PLUG LEAKAGES 1

If the header plug leak, additional tightening to certain extend may be required but must not distort the gaskets. Otherwise the gaskets should be replaced. The header plug can be retightened to maximum 350 ft-lbs. Refer to Header Plug Torquing and Installation Procedure 100-8137-00-ME-PRO0017 for detail.

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4.3

4.4

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If leak still exist, remove shoulder hex plug and gaskets and clean the spot face. Reinstall new shoulder hex plug and gasket and tighten at required torque until leakage resolve. The spot face may need to be repaired if the smooth finishes face is damage or badly rusted. The spot face shall be repaired using tube facing and beveling machine, e.g Krais MiniMill 600 until smooth finishes face is obtained.

TUBE LEAKAGES 1

If tube wall leakages, it is usually due to corrosion. The most practical method is to insert tube plug into both end of tube. Before any decision is made to plug the tube, the thermal study shall be re-visited to ensure no heat transfer surface loss.

2

If leakages develop in tube to tubesheet strength weld joint, the practical method is to insert tube plug into both end of tube.

3

If tube leakage reaches 20% of total tubes, the tube bundle is beyond repair and shall be replaced.

MECHANICAL PART 4.4.1

MOORE FAN During the first week of operation, at least one inspection should be made. At these initial inspections, the items need to inspect shall as follows: a)

Check all nuts for tightness to make certain that all were tightened properly at installation.

b)

Check blade angle and running position. Turn off the unit and watch the blade tips. A looseness in the clamp bolt will permit a blade flatten in angle. This usually can be detected by looking at tips of the blades while the fan is slowing down. At same time, before the units comes to a complete stop, watch track of blade tips to see all blades move to the same operating position.

c)

Inspection of Hub. Check the hub for any sign of bending or twisting of the hub tubes. Hub tubes can’t be replaced in the field on manual fans and new hub should be order. Bushings are frequently cracked during a fan wreck and should be carefully inspected. Damaged may occur to the studs that attach the hub to the bushing. It is a good idea to replace the studs when replacing a damaged fan blade. Check any cracks, dents may be occurs on fan.

Annual Inspection a) 100-8137-00-ME-PRO-0022_Rev.R1

A smooth blade surface is essential for efficient fan




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performance. If an incrustation forms on the blades it should be removed. Use steel wool as an abrasive a ling with mild detergent or a very mild form of solvent. Lye must not be used because it attacks aluminum readily.

4.4.2

b)

Check blade angle and adjust if necessary. Checking Blade Load.

c)

The yearly inspection should be a very thorough one. All nuts and bolts should be checked and careful scrutiny given to all highly stressed area.

d)

Grasp each blade and feel for looseness at the mount. If in doubt, the blade should removed and the mount assembly visually inspected,

e)

Inspect the blade tips for any signs of cracks, dents and corrosion.

ELECTRICAL MOTOR The following should be checked at regularly intervals: a)

Windings should be dry and free from dust, grease, oil and dirt. Windings may be cleaned by suction cleaners or by wiping. Nozzles of suction type cleaners should be nonmetallic. Gummy deposits of dirt and grease may be removed by using a commercially available low volatile solvent.

b)

Terminal connections, assembly screws, bolts and nuts should be tight. They may loosen if motors is not securely bolted and tend to vibrate.

c)

Insulation resistance of motors in service should be checked periodically at approximately the same temperature and humidity conditions to determine possible deterioration of the insulation. When such measurements at regular intervals indicate a wide variation, the cause should be determined. Motor should be reconditioned if motor has been subjected to excessive moisture by re-winding or re-insulating if necessary. Enclosed motors require very little attention.

4.4.3

DRIVE SYSTEM

1

Inspect guard for looseness or damage. Keep it free of debris and grime buildup of the guard.

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2

Inspect motor mounts for proper tightness

3

A quick visual and noise inspection can be performed every one or two weeks.

4

A drive shutdown for a thorough inspection of belt, sheaves or sprocket, bearing and other drive components may be required every three to six months. By following these steps, belt drives and component can be maintained efficiently and safely 1.

Always shutdown off power to the drive. Lock the control box and tag it with warning sign “Down for Maintenance. Do Not Turn Power On.” Make sure the power is turned off for the correct drive.

2.

Test to make sure correct circuit has been turned off.

3.

Place all machine components in a safe (neutral) position. Make sure moving components are locked down or are in a safe position. Make sure fans cannot unexpectedly freewheel.

4.

Remove guard and inspect for damage.

5.

Inspect belt for wear or damage. Replaced if needed.

6.

Inspect sheaves or sprockets for wear and misalignment. Replace if worn.

7.

Inspect other drive for drive components such as bearings, shaft, bolts and nuts.

8.

Inspect the grease line from loose or damage. Replace if needed.

9.

All bearing should be greased in manufacturer’s maintenance practice.

10.

Inspect static conductive grounding systems (if used) and replace components as needed.

11.

Check belt tension and adjust as needed.

12.

Recheck sheave or sprocket alignment

13.

Reinstall Drive Guard.

14.

Turn power back on and restart drive. Look and listen for anything unusual.

accordance

with

4.4.4

VIBRATION SYSTEM

1.

Perform functional test on the vibration transmitter and ensure the

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transmitter is working properly. Replace if necessary. 2.

Perform a visual check on the vibration transmitter cover and ensure the mounting case/adaptor is properly tightened to vibration sensor.

3.

Ensure operators are able to monitor the vibration status on DCS during functional test of vibration transmitter.

4.

Please refer to Vibration Transmitter Installation Manual for information on installation and configuration.

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Operating & Maintenance Procedure for Air Cooler Heat Exchanger

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