00 161 PD 0004

RAS TANURA REFINERY CLEAN FUELS PROJECT 10100
PIPING CLEANING PROCEDURE PAGE 2 OF 15
10100-00-161-PD-0004 REV.: 00
INDEX
1. PURPOSE ....................................................................................................................... 3
2. SCOPE............................................................................................................................ 3
3. DEFINITIONS .................................................................................................................. 4
4. DEVELOPMENT ............................................................................................................. 5
4.1 SAFETY CONSIDERATIONS ................................................................................... 5
4.1.1 Health, safety and environment ........................................................................ 5
4.1.2 Precautions ........................................................................................................ 6
4.2 GENERAL ................................................................................................................. 7
4.2.1 Air blowing ......................................................................................................... 7
4.2.1.1 Air accumulation/Quick decompression method ....................................... 8
4.2.1.2 Direct blowing method ................................................................................. 8
4.2.1.3 Planning ........................................................................................................ 8
4.2.1.4 Preparation.................................................................................................... 9
4.2.1.5 Material resources ........................................................................................ 9
4.2.1.6 Execution .................................................................................................... 10
4.2.1.6.1 Air accumulation/Quick decompression method ............................... 10
4.2.1.6.2 Direct blowing method ......................................................................... 10
4.2.2 Water flushing .................................................................................................. 10
4.2.3 Water quality considerations .......................................................................... 10
4.2.3.1 Planning ...................................................................................................... 11
4.2.3.2 Preparation.................................................................................................. 11
4.2.3.3 Material resources ...................................................................................... 12
4.2.3.4 Execution .................................................................................................... 12
4.3 ACCEPTANCE CRITERIA ...................................................................................... 13
4.3.1 Air blowing ....................................................................................................... 13
4.3.2 Water flushing .................................................................................................. 13
4.4 POSTWORK ........................................................................................................... 13
4.4.1 Air blowing ....................................................................................................... 13
4.4.2 Water flushing .................................................................................................. 14
5. REFERENCES .............................................................................................................. 14
5.1 COMPANY DOCUMENTS ...................................................................................... 14
5.2 PROJECT MANAGEMENT SYSTEM PROCEDURES ........................................... 15
This document is property of UTE TR Naphtha RT and TR Saudia for Services and Contracting Co Ltd.
Its reproduction without previous permission in writing is strictly forbidden.
10100-00-161-PD-0004 REV.: 00
1. PURPOSE
The object of this document is to describe the general requirements for carrying out Piping
Cleaning (Air blowing/Water flushing) applied to piping system in Ras Tanura Refinery Clean
Fuels Project.
This document neither abrogates nor modifies the contractual agreements between the
COMPANY and CONTRACTOR but provides the mechanism for carrying out the normal
working relationship between the parties during the Project execution.
2. SCOPE
Air blowing can be applied to the following pipes and equipment:
 Chemical lines
 Instrument/Plant Air lines
 Hydrogen lines
 Nitrogen lines
 Stainless steel lines
 Fuel gas lines
 Combustion air lines
 Cold service lines
Air blowing, however, may not be limited to only the above, but may be applied to other
service:
 Lines following water flushing, when applicable
 Equipment compulsory requiring air blowing
 Lines or systems where water flushing is not considered practical in order to keep dry
the pipework and equipment
 Systems where a sufficient flow of water is not achievable because of the large pipe
diameter
Water flushing can be applied to the following pipes and equipment:
 Lines where water is their operating flow:
o Demineralized and potable water lines
10100-00-161-PD-0004 REV.: 00
o Utility water lines
o Boiler feed water lines
o Cooling water lines
o Fire water lines
 Process lines which normal operating flow are liquid phase fluids and where small
water traces is not a problem for process or when the lines will be dried out after
water flushing.
 Equipment requiring water flushing
3. DEFINITIONS
COMPANY: ARAMCO OVERSEAS COMPANY B.V. (OOK).
Saudi Arabian Oil Company (Saudi Aramco) (IK).
CONTRACTOR: UTE TR Naphtha RT (OOK)

Técnicas Reunidas Saudia for Services and Contracting
Co Ltd. (IK).
FACILITIES: The structures or items being constructed, installed or

repaired by CONTRACTOR.
MSDS: Material Safety Data Sheet.
PRECOMMISSIONING: All activities following fabrication, installation or

construction required to prepare the Facilities for
Mechanical Completion including, but not limited to, any
testing, flushing, cleaning, or inspection tasks required
prior to validating the Facilities for actual designed
functions during Commissioning.
PROJECT: Ras Tanura Refinery Clean Fuels Project

Package 1 – Naphtha Processing Facilities
Package 2 – Offsites & Utilities
P&ID: Piping & Instrument Diagram.
10100-00-161-PD-0004 REV.: 00
SUBCONTRACTOR: Any person, or entity to whom execution of any part of

the WORK is contracted directly or indirectly by
CONTRACTOR.
VENDOR: Supplier of materials and or equipment for the

FACILITIES other than the CONTRACTOR or the
Affiliated Contractor, including the provision of related
documentation and services, and when necessary or
applicable, installation, testing, Pre-Commissioning,
Commissioning and Start-Up support services for such
materials and / or equipment.
4. DEVELOPMENT
4.1 SAFETY CONSIDERATIONS
Safety precautions during the piping cleaning shall be in accordance with the following
aspects:
4.1.1 Health, safety and environment
 Ensure that permit to work has been issued before proceeding with work.
 Operator team should be managed by experienced and trained personnel.
 Ensure that all required Personal Protection Equipment (hardhat, safety glasses,
safety shoes, safety gloves, etc.) are provided and worn by personnel involved in the
activity.
 Ensure all the personnel near the area are properly advised of the activity.
 Ensure that correct materials are used to prevent accident or injury to personnel.
 For height works the use of safety harness and/or life lines are compulsory.
 Access to operating points must allow safety movements.
 Portable eye washer should be available (if not available operative safety
showers/eye washer in working area); either temporary or permanent.
 MSDS’s must be available and Personal Protection Equipment will be provided

according to MSDS’s specifications.
10100-00-161-PD-0004 REV.: 00
4.1.2 Precautions
 Check that line supports and temporary accessories near flow outlet are adequate
to avoid line movements.
 Before removing any line accessories, it must be checked that line is

depressurized and empty.
 Safe access to all operation points to be provided.
 Any equipment opening facing to air discharge point shall be covered to prevent
foreign materials from entering and damaging the equipment.
 Air blowing is not carry out through control valves, exchangers or vessels, unless
the line to such a device has been cleaned first.
 Air pressure shall never exceed 80 psig.
 The execution of flushing works shall include the necessary measures for safety,
cleaning of area and disposal of the waste water.
 Ensure that water outlet points are properly barricaded. “Water Flushing on
going. Keep out” signs shall be clearly displayed on the barricade.
 Ensure that appropriate hoses, fittings and connections are used to prevent
accidents or injuries to personnel. Temporary fittings and spools shall be approved
and tested.
 A suitable communication method (e.g. two way radio) shall be available and
operative among personnel in the activity.
 During flushing, design pressure of the system cannot be exceeded. Specific

procedure should indicate maximum pressure to be used, taking into account the
system and equipment design.
 During water filling and/or drainage of lines and equipment, vents should be
maintained fully open in order to avoid overpressures or vacuum in lines and
equipment.
 Water used for flushing should be with normal operation quality: raw water, utility
water, potable water or demineralized water. In order to avoid stress corrosion
cracking, allowable chlorine ion concentration in water should be below 50 ppm for
austenitic stainless steel pipes and piping components in contact with water.
10100-00-161-PD-0004 REV.: 00
 All lines or systems to be subject to water flushing shall be properly supported.

Dragging forces produced during flushing could cause the line is displaced.
 All electric equipment which can be affected during flushing water drainage
(motors, junction boxes, etc.) should be protected with plastic covers.
 The suction side of temporary pumps to be used for flushing, must be equipped
with a strainer to catch foreign materials. For strainers, 20 mesh temporary
screens are normally recommended.
 Whenever a vessel full of water has to be emptied, a special note will be issued to
state that a vent will have to be opened previously in order not to create a vacuum
in the vessel.
 Take suitable measures to prevent that dirty water enters any permanent
equipment, specially pumps, compressors, and heat exchangers.
 System to be cleaned must be isolated from the other adjoining systems.
 Drain/vent points should never be cleared with sticks and/or other manual tools if
line is not completely depressurised.
4.2 GENERAL
Pre-commissioning and Commissioning Team may change or modify this procedure

depending on the current situation at site.
4.2.1 Air blowing
Air blowing is one cleaning method that cleans with the kinetic energy of an air flow.
Foreign materials such as sand, debris, rust and weld slag located inside pipes are
removed due to the effect of the air flow. Since the specific gravity of air is small, high
velocity is required to obtain large kinetic energy.
Air for blowing will be supplied from Utility air header or temporary portable dry and oil free
air compressor(s) shall be used in case the permanent air supply compressor(s) are not
ready.
During the air blowing, larger lines or headers are blown first, followed by smaller lines,
branches or sub-headers.
Air blowing may be developed by one of the following methods described here bellow.
10100-00-161-PD-0004 REV.: 00
4.2.1.1 Air accumulation/Quick decompression method
Compressed air is accumulated in a suitable reservoir such as column/drum/vessel/big

bore piping associated with the piping to be blown. A valve should be located as close to
the reservoir as possible to produce maximum velocity in the pipe. Then, the piping
connected is blown by opening the valve or breaking the rupture disc. Temporary or
permanent equipment can be utilised as a reservoir. Caution should be taken to ensure air
is blown / vented to a safe location.
4.2.1.2 Direct blowing method
The pipe to be air blown to atmosphere is directly connected to the air supply source via
temporary pipe or air hose.
This method is typically applied to small bore pipe and vessels. A suitable air supply source
is required, either from the utility air supply header or from a temporary compressor.
4.2.1.3 Planning
Air blowing route shall be defined and marked up on the P&IDs in the detailed air blowing
procedure.
The following items shall be indicated on the P&IDs:
 Air inlet points
 Air discharge points
 Valves to be operated
 Temporary piping, spools and blinds, if any
 Pipe accessories and instruments to be removed
Line or system to be air blown shall be previously hydro-tested (not required in piping class
Category D, as defined in ASME B31.3) and properly supported. Release from hydro-
testing is mandatory.
If a rupture disk (bursting disc) is to be installed on a large diameter pipe, the set pressure
of the disc shall be carefully calculated in order to limit the energy released when bursting
occurs to an acceptable level (In particular with regard to recoil effect). Supports shall be
always verified.
When plastic sheets are used as bursting accessory, trial and error method is used to
achieve the desired bursting pressure.
10100-00-161-PD-0004 REV.: 00
4.2.1.4 Preparation
Prior to the commencement of blowing, the air-blowing route shall be checked (walked
down) at site by the Pre-commissioning Team in charge of this system using the prepared
detailed procedure.
Following items, if any, shall be isolated or removed:
 Safety valves
 Check valves, as required
 Self-activated valves except ball/gate type ones
 Emergency shut off valves except ball/gate type ones
 Rupture disks
 Spargers
 Orifice plates or turbines flowmeters, and other flowmeter elements
 In-line mixers, strainers and filter elements
 Spray nozzles
 Control valves except ball type
4.2.1.5 Material resources
Following items shall be available for air blowing execution as temporally facilities:
 Air hoses
 Hose arrestors (hose safety whip checks)
 Air hose connection flanges. (Tested and certified)
 Temporary ball valves screwed and flanged. (Tested and certified)
 Temporary Klinger Gaskets
 Portable oil free air compressors
 Temporary flanged connections. (Tested and certified)
 Calibrated Pressure indicators
 Temporary spools (Tested and certified)
PAGE 10 OF
PIPING CLEANING PROCEDURE 15
10100-00-161-PD-0004 REV.: 00
4.2.1.6 Execution
4.2.1.6.1 Air accumulation/Quick decompression method
 Check that the circuit is isolated.
 Check that all safety measures have been adhered to.
 If a quick opening valve is used, allow the air to enter the circuit and carefully check
that pressure in the system never exceeds the maximum allowable pressure. When
the required pressure is reached, quickly open the valve. This operation shall be
repeated as many times as needed. First, blow the main headers/lines and then
proceed to their branches.
 If a rupture disk is used, allow compressed air to enter the circuit; check
continuously the pressure rise, and when the rupture disk blows out, stop the air
inlet in the circuit. This operation shall be repeated as many times as needed.
4.2.1.6.2 Direct blowing method
 Start the air compressor (when used).
 Open the valves on the main header to be air flushed.
 Allow the air flow to enter the network.
 If the valve between the compressor and the network to be flushed is a globe valve,
and if the compressor allows for quick increases of flow rates, changes of flow rates
in the line may be made. By changing the air velocity, a more effective removal of
rust and scales from surfaces can be achieved. For loose dirtiness, a continuous
blowing at a constant speed should be sufficient.
4.2.2 Water flushing
Water flushing is one cleaning method that cleans with kinetic energy of a water flow.
Foreign materials such as sand, rust and weld slag located inside pipes will be removed by
the kinetic energy of the water flow.
During the pre-commissioning stage water flushing is carried out with pumped water by the
pumps installed permanently or with temporally pump facility.
4.2.3 Water quality considerations
Material Specifications should indicate type of water to be used to prevent corrosion

problems.
PAGE 11 OF
10100-00-161-PD-0004 REV.: 00
Pipe Material Flushing water to be used

Carbon steel Raw water / Fire water
Copper Tubbing Raw water / Fire water
S.S. AISI 304 L Demineralised water (<50ppm Cl)
Monel Raw water / Fire water
Glass lined C.S. Raw water / Fire water
Sanicro Raw water / Fire water
Duplex Demineralised water (<50ppm Cl)
Potable water lines Potable water
Fiber Glass Reinforced
Raw water / Fire water
Plastic
4.2.3.1 Planning
Big bore piping are not recommended to be water flushed because of the big amount of
water and pumping capacity to be required.
Water flushing route shall be defined and marked up on the P&IDs in the system’s detailed
water flushing procedure.
The following items shall be indicated on the P&IDs:
 Water supply point and water supply source.
 Water discharge points.
 Valves to be operated.
 Temporary piping, spool and blind spectacles, if any.
 Pipe accessories and instruments to be isolated or removed.
The diameter of the outlet pipe shall be at least 2/3 of the diameter of the line to be cleaned,
and at least as large as the inlet pipe.
Provision of an air connection is recommended to enhance drain out by air sweeping after
water flushing.
4.2.3.2 Preparation
Prior to the commencement of flushing, the route shall be checked (walked down) at site by
the Pre-commissioning Team in charge of this system using the prepared detailed
procedure.
PAGE 12 OF
10100-00-161-PD-0004 REV.: 00
Following items, if any, shall be isolated or removed:
 Safety valves
 Check valves, as required
 Self-activated valves except ball/gate type ones
 Emergency shut off valves except ball/gate type ones
 Rupture disks
 Spargers
 Orifice plates or turbines flowmeters, and other flowmeter elements
 In-line mixers, strainers and filter elements
 Spray nozzles
 Control valves except ball/gate type ones
4.2.3.3 Material resources
The following items should be available for water flushing execution:
 Water hoses
 Hose arrestors (hose safety whip checks)
 Water hose connection flanges. (Tested and certified)
 Temporary ball valves screwed and flanged. (Tested and certified)
 Temporary Klinger Gaskets
 Portable diesel pumps and portable tank
 Temporary flanged connections. (Tested and certified)
 Calibrated Pressure indicators
 Temporary spools (Tested and certified)
4.2.3.4 Execution
 Water is introduced to the pipes to be flushed at available maximum flow within the
limit of draining capacity of the pipe.
 Whenever possible, the cleaning fluid shall flow from top to bottom.
PAGE 13 OF
10100-00-161-PD-0004 REV.: 00
 First, flush the main headers/lines and then proceed to clean the branches.
 During flushing, it is very important to get as much water velocity as possible in

order to remove from line all the foreign material and particles.
4.3 ACCEPTANCE CRITERIA
4.3.1 Air blowing
Cleanliness criteria: The color of the air at the exit point will indicate whether or not rust and
dirt remain in the piping. This is usually sufficient for the majority of process and utilities
piping.
When the cleaning criteria is more restrictive, install a white fabric or cardboard in front of the
air blowing exit for checking air cleanliness by observing the presence of particles impacting
on the white surface. The fabric or cardboard must be fixed to the pipe or well supported to
avoid it to blow or move by the exiting air flow. It will never be supported by hand in front of
the air flow.
Cleaning results shall be recorded on SATR-A-2008 (Internal Cleanliness Report Piping

Systems & Equipment) to be signed by CONTRACTOR and COMPANY. This signed form
shall be included in the System’s Mechanical Completion Dossier.
The flushing is deemed completed when foreign materials that will interfere with system
normal operation are no longer visualized in flushed water and the effluent water is clear.
For plant water flushing, acceptance criteria should be that the color of the water outlet
must be similar to the quality of the water inlet. The color should be checked by taking a
water samples in a plastic or glass transparent bottle. It should be noted that in Carbon
Steel lines, color of water at the outlet point will be always yellowish.
Cleaning results shall be recorded on SATR-A-2008 (Internal Cleanliness Report Piping

Systems & Equipment) to be signed by CONTRACTOR and COMPANY. This signed form
shall be included in the System’s Mechanical Completion Dossier.
4.4 POSTWORK
4.4.1 Air blowing
 Instruments removed or isolated shall be reinstated on completion of the air

blowing. “Re-instatement Checklist” (SATR-A-2011) shall be accomplished.
PAGE 14 OF
10100-00-161-PD-0004 REV.: 00
 Lines will remain under slightly positive dry air pressure (5 psig) until next
precommissioning activity is performed. E.g. Leak Test.
 Suitable measures shall be taken for pipes where air blowing has been finished, so
that no dirt is allowed to go inside pipes again. Preservation must be applied.
 All lines, no matter the material, shall be carefully drained after water flushing.
Exception can be Colling Water systems which usually remain filled because the
big volume of water used when flushing with the Cooling Water pumps. In these
cases, recirculation should restart as soon as possible jointly with the chemical
treatment.
 All equipment, instruments or elements previously removed or isolated shall be

reinstated on completion of the water flushing and “Re-instatement Checklist”
(SATR-A-2011) shall be filled and signed.
 After draining and elements’ reinstallation, systems shall be dried with dry and oil
free air up to -1 ºC dew point for preservation purposes.
 Signing on the document for completion of the water flushing, as per reference to
“Internal Cleanliness Report” (SATR-A-2008).
 Suitable protective measures shall be put in place systems where flushing has been
finished to avoid ingress of dirt. Temporary blinds and locked close valves are
normally used to protect the already cleaned systems.
 CONTRACTOR shall follow SAEP-327, Disposal of Wastewater from Cleaning,

Flushing and Dewatering Pipelines and Vessels in order to plan and perform the
flushing water disposal at the end of the water flushing operations.
5. REFERENCES
5.1 COMPANY DOCUMENTS
Contract IK (6600038540) & Contract Ras Tanura Refinery Clean Fuels Project
OOK (6600038541) (Package 1 – Naphtha Processing Facility)
Contract IK (6600038542) & Contract Ras Tanura Refinery Clean Fuels Project
OOK (6600038543) (Package 2 – Offsites & Utilities )
PAGE 15 OF
10100-00-161-PD-0004 REV.: 00
SAEP-327 Disposal of Wastewater from Cleaning,

Flushing and Dewatering Pipelines and
Vessels
SAEP-388 Cleaning of Pipelines
SAES-B-017 Fire Water System Design
SAES-J-901 Instrument Air Supply Systems
SAES-S-040 Saudi Aramco Water Systems
SAES-L-350 Construction of Plant Piping
SAES-S-070 Installation of Utility Piping Systems
SATR-A-2008 Internal Cleanliness Report
SATR-A-2011 Re-instatement Checklist
5.2 PROJECT MANAGEMENT SYSTEM PROCEDURES
Pre-Commissioning and Mechanical

10100-00-161-PD-0001
Completion Plan
10100-00-090-PD-0002 Site Quality Plan
10100-00-150-PD-0003 Construction Subcontracting Plan
10100-00-150-PD-0004 Field Materials Management Plan
10100-00-091-PD-0005 Contractor Site Safety Program (CSSP)

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RAS TANURA REFINERY CLEAN FUELS PROJECT 10100

PIPING CLEANING PROCEDURE PAGE 2 OF 15

Air blowing can be applied to the following pipes and equipment:

 Instrument/Plant Air lines

 Stainless steel lines

 Fuel gas lines

 Combustion air lines

 Cold service lines

 Lines following water flushing, when applicable

 Equipment compulsory requiring air blowing

Water flushing can be applied to the following pipes and equipment:

 Lines where water is their operating flow:

o Demineralized and potable water lines

o Utility water lines

o Boiler feed water lines

o Cooling water lines

o Fire water lines

 Equipment requiring water flushing

COMPANY: ARAMCO OVERSEAS COMPANY B.V. (OOK).

Saudi Arabian Oil Company (Saudi Aramco) (IK).

CONTRACTOR: UTE TR Naphtha RT (OOK)

FACILITIES: The structures or items being constructed, installed or

MSDS: Material Safety Data Sheet.

PRECOMMISSIONING: All activities following fabrication, installation or

PROJECT: Ras Tanura Refinery Clean Fuels Project

P&ID: Piping & Instrument Diagram.

SUBCONTRACTOR: Any person, or entity to whom execution of any part of

VENDOR: Supplier of materials and or equipment for the

4.1 SAFETY CONSIDERATIONS

 Operator team should be managed by experienced and trained personnel.

 Access to operating points must allow safety movements.

 MSDS’s must be available and Personal Protection Equipment will be provided

 Before removing any line accessories, it must be checked that line is

 Safe access to all operation points to be provided.

 Air pressure shall never exceed 80 psig.

 During flushing, design pressure of the system cannot be exceeded. Specific

 All lines or systems to be subject to water flushing shall be properly supported.

 System to be cleaned must be isolated from the other adjoining systems.

Pre-commissioning and Commissioning Team may change or modify this procedure

4.2.1 Air blowing

4.2.1.1 Air accumulation/Quick decompression method

Compressed air is accumulated in a suitable reservoir such as column/drum/vessel/big

4.2.1.2 Direct blowing method

The following items shall be indicated on the P&IDs:

 Air inlet points

 Air discharge points

 Temporary piping, spools and blinds, if any

 Pipe accessories and instruments to be removed

Following items, if any, shall be isolated or removed:

 Check valves, as required

 Self-activated valves except ball/gate type ones

 Emergency shut off valves except ball/gate type ones

 Orifice plates or turbines flowmeters, and other flowmeter elements

 In-line mixers, strainers and filter elements

 Control valves except ball type

4.2.1.5 Material resources

 Hose arrestors (hose safety whip checks)

 Air hose connection flanges. (Tested and certified)