Utilities and Complementary Items For Tower Internals in Plants & Refinery
i. During first inspection
AXENS to supply in due time detailed procedure for inspection of the adsorbers
✓ Powerful lighting shall be available inside the adsorbers right from the moment the scaffolding is being erected. (Owner or subcontractors to provide)
✓ Chalk or neutral paint sticks to be available. (Owner or subcontractors to provide)
✓ Several spirit levels in the size of 0.5 meters to about 2 meters to be provided. (Owner or subcontractors to provide)
✓ Tape measurement, one short 2 meters, one long – 10 meters. (Owner or subcontractors to provide)
✓ Special laser to allow dimensions measurement. AXENS will have one available. If necessary to get more Owner or subcontractors to provide.
✓ Special laser device to check horizontality of rings, beams, potentially panels, etc … (Owner or subcontractors to provide). Eventually verticality of the adsorbers as well as of the Center Pipe shall be checked.
✓ Argon and all necessary means for welding as well as performing ND test.
✓ Magnetic particles distribution instrument shall be available on request, if any welding as to be done or repaired in the shell of the adsorbers. (Owner or subcontractors to provide)
ii. At top platform only, during internals installation
✓ Enough power lighting for the outside of the adsorbers. In particular the top platform should be lightened to be able to work on night time.
✓ Normal power plugs shall be available for several tools to be used at the same time. Especially for grinding in the special dedicated area of the top platform and for welding inside the adsorbers during lower tray and upper tray piping installation. (Owner or subcontractors to provide)
✓ Four 200 liter very clean steel or plastic drums on a pallet to store temporarily the sieve in excess. To be provided by Owner/subcontractor.
✓ A metal holder to suspend one of the above mentioned drum if necessary. To be provided by Owner/subcontractor.
✓ A desk to be provided by Owner or subcontractor.
✓ Fresh drinking water to be available on a special dedicated area on the top platform as well as at ground level for all workers.
No water is allowed inside the adsorbers as well as inside any shelters or temporary storage containers.
✓ Plumb line to be able to check the centering of the Center Pipe to be exactly centered with the center of the inlet P/ A nozzle at the top of the adsorbers. (Owner or subcontractors to provide)
• Portable air (02) analyzers with alarm devices should be available at any time to check the minimum oxygen content in the vessel (personnel protection) especially during GI AW welding.
• A portable moisture and temperature analyzer shall be available to be sure that the dry air flushing is good enough to avoid any humidity entry inside the adsorbers.
iii. Required for work at every floor (including top platform) during internals installation
✓ Powerful lighting to be able to safely and easily work at night shall be available,
✓ Dry and oil free air to ventilate the adsorbers (minimum flow >5 Nm3/mn to get a velocity > 3 cm/s outlet of the top MH, dew point -10°C). (Owner or subcontractors to provide). This will allow circulating air inside the adsorbers and preventing the possible dusty and humid air from outside to entry the vessels.
This will prevent as far as possible rust formation on the beams and the shell during the installation.
V A minimum of three pairs of walky talky to be available for communications from inside to outside. (Owner or subcontractors to provide) V Power low voltage (Low intensity) for lighting and normal power for tools. (Owner or subcontractors to provide)
• Enough power low voltage (low intensity) plugs shall be available for several lighting inside the adsorbers. They will be used at the same time. The lighting shall be such that there will be no problems for intermediate as well as final inspection. In addition piping shall be well lighted so that the welders can make proper welding.
• Special dedicated lighting shall be provided for the Catapac platform as well as for loading profile checks.
At least 6 powerful flashlights will be available as well as spare battery to avoid being short in portable lighting. (Owner or subcontractors to provide)
At least one pencil type powerful flashlight will be available for inspection of the flexible hoses during final inspection. (Owner or subcontractors to provide)
At least two portable powerful lighting will be available in both adsorbers, to be able to make a proper inspection in any location of the internals assembly especially for bottom part of piping, annular chamber welding checks, and for checking the proper gasketing. (Owner or subcontractors to provide)
V At least two very powerful vacuum cleaners will always be available for cleaning the inside of the adsorbers before final cleaning and potentially for intermediate inspection. (Owner or subcontractors to provide)
✓ Argon and all necessary means for welding as well as ND testing. Should be used for Upper and Lower trays only.
✓ Dry, oil free, air for leak tests (0.5 bar g, dew point -40°C).
(Instrument air for instance). Used for Upper and Lower trays. (Owner or subcontractors to provide)
✓ Potentially dry air for air tools if any. (Owner or subcontractors to provide)
iv. For beams installation,
✓ Carbon steel or stainless steel shims of various thickness to adjust the levelling horizontality of all beams. Such shims could be fabricated on site on request or provided by beams supplier.
✓ Shims will be tack welded in place.
✓ Stud and nuts to be provided by the beams supplier. (Owner or subcontractors to provide)
✓ To check levelness and horizontality. Checking to be done using the same material as during first inspection of the adsorbers.
✓ At least two numbers of the following beams lifting devices or equivalent is required.
Figure 17: Typical beam lifting device.
✓ Chain block to be able to put the beam in any required position to be able to install them. (Owner or Subcontractors to provide).
✓ Threaded holes in the beams will be rechecked for proper threading (No damage and clean). Owner/Subcontractor to provide the threading check devices.
v. For panels assembly,
It will be necessary to get (AXENS to supply in due time detailed procedure for panels assembly):
✓ Chain block, the same as used for the beams.
✓ Metal spacers and screw clamps to maintain the required gap between every panel. Panels supplier to provide proper spacers and screw clamps in such number that at least enough two trays (one on each adsorbers) can be simultaneously assembled.
Figure 18: Spacers and screw clamps for panels positioning.
✓ Crowbars, hammers. Owner or subcontractor to provide.
✓ Field GTA W welding machines and supplies for upper and lower trays welding operations, as well as to be able to make
any necessary repairs at ground level (Panels, piping, etc … ). (Owner or subcontractors to provide).
• Dye penetration check to be provided in enough amount to be able to proceed to dye checking of the welds
• Enough filler of the proper specifications according to welding procedure which shall have been provided by subcontractor and approved by AXENS, shall be available.
• Argon for GT AW welding to be provided with the proper purity to make a proper GTA W welding.
• In case of screen damage, the screen manufacturer’s representative on site must be involved in the repair.
✓ Glass fiber rope (from 8 to 30 mm diameter). Trays supplier to provide several diameters as per AXENS recommendations.
✓ Steel wire rope to be used for Lower Trays installation to avoid glass fiber rope blocking the V3 nozzle.
Requirements are such as minimum three meters on each side of the V3 nozzle are covered. As the main purpose of this item is the same as rope arrestor, steel wire rope diameter should be determined depending on observed gap once lower tray is installed.
✓ Rope packing tools provided by tray supplier.
Figure 19: Rope packing tools.
✓ Forks, plates, nuts, clamps, washers if needed, to fasten the lower tray. The fork will be either with double nuts or one tack welded nut. Some shims of various thicknesses shall be available for the clamps. (If any shim is used it will be tack welded). Supplier of the panels to provide enough of these items for both adsorbers.
✓ Studs, nuts, clamps and washers to fasten the upper and the lower trays to beams. Supplier of the panels to provide enough of these items for both adsorbers.
✓ Flats and angle bars to be welded panel to panel, panel to shell, and panel to Center Pipe on the lower and upper tray. These seal cover plates are provided by tray manufacturer.
✓ Center Pipe tightness blanket and associated elements. Provided by tray manufacturer.
✓ Bolts, nuts, gaskets (temporary one as well as final one) for internal piping flanges. Supplier of the panels to provide enough of these items for both adsorbers and 24 trays. Total numbers per diameters to be checked on site prior to start the internals installation. At least 10 % gaskets spare shall be available.
✓ Vacuum cleaner (See above for vacuum cleaners used during initial inspection of the adsorbers).
Special Neoprene protection is required for the panels, during temporary storage, handling and installation. The neoprene sheet thickness is large enough to protect the screen from any damage of falling object (10 mm). At least two complete sets of the neoprene sheets and a spare set are needed. (Owner or subcontractor to provide)
The neoprene shall be on one piece and perfectly adjusted to the tray panel geometry. Large and soft but unyielding and easily removable tape shall be provided. It should stitch neither on the neoprene nor the panels frame after removing as resulting cleaning phase may be very time consuming.
Figure 20: Neoprene sheets and adhesive tape for screen panel protection.
✓ Special gauges to be provided to be able to check the gap between two wires on the panels upper and lower profiled wire screen. These gauges are also used to check the gaps between the screen and the frame of the panels. The gauge feeler is 0.223mm and no-go checking should be performed. Owner or subcontractors to provide.
vi. For sieve loading
AXENS to supply in due time detailed procedure for sieve loading which is done by AXENS Catapac specialist
✓ Hoppers installed and equipped as previously specified
✓ A rigid and transparent plastic cover to install on the manhole during sieve loading. To be provided by Owner/subcontractor.
Figure 21: Manway removable Plexiglas cover.
This Plexiglas cover will allow the AXENS dense loader to see through, and prevent to get harmful sieve dust outside. It should be easily removable to allow the dense loader to go inside to survey the sieve profile and to check the Catapac good operation.
- In order to safely store all the Catapac tools as well as the AXENS material, two metals coffers which can be safely locked will be provided to AXENS.
Figure 22: Typical AXENS CATAPAC tools coffers.
✓ Sieve levelling scrapers made of aluminium.
Figure 23: Sieve levelling scrapers.
✓ At least 48 Samples plastic bottles of ~0.5 liters to I liter to be available. 2 plastic bottles are required for sampling of each bed to be loaded. The bottles cover shall be seal tight type.
✓ Several plywood working boards (At least three for each adsorbers) to allow access to bed for panels installation
✓ Small shovels, Small brooms and 20 liters buckets with handles to remove sieve in excess.
vii. Safety
The following safety measures are only the one recommended by AXENS and shall not be considered as exhaustive list. Safety department to complete this list according to local codes and refinery usual practice.
(1) At top platform
✓ Safety life line and harness to be available and attached close to the top manhole. This life line is mainly used by AXENS Catapac operator while he stops the machine to cross check loading profiles (There is no more protection as the Catapac is in loading position). To be provided by Owner/subcontractor.
V A guardrail could be foreseen around the top manhole to prevent any casual fall especially if the top of this MH is very close to the platform level. To be provided by Owner/subcontractor.
V A closed wardrobe to store the safety equipment. To be provided by Owner/subcontractor.
V Harnesses, lifelines, to be provided for the personnel working inside. Owner safety department to provide.
(2) Inside the adsorbers
V The temporary removable ladder on the Center Pipe (refer to §
4.b.iii.4) will be used in case of emergency. During sieve loading and trays installation, due to the dust accumulated
during the loading on the temporary Center Pipe ladder, the ladder is used only in case of absolute necessity.
V In addition to the temporary ladder on the Center Pipe AXENS recommends that in case of emergency of any kind, including personnel, the baskets (see figure 12 page 55) shall be always available on the top platform to be able to evacuate the
personnel from inside the adsorbers.
✓ In case of power failure, an emergency alternate source of Power might be provided to be able to operate the top platform hoists.
✓ Harnesses, lifelines, to be provided for the personnel working inside. Owner safety department to provide.
viii. Documents requested by AXENS (One paper copy and one electronic copy):
✓ As built Supplier/manufacturer drawings,
✓ All packing lists for beams,
✓ All packing lists for panels,
✓ All packing lists for piping,
✓ All packing lists for miscellaneous, gaskets, special tools, spare parts, spare bellows, etc …
V Hydrotest reports related to adsorbers and Center Pipes, V Tightness reports for all annular chambers,
✓ All detailed drawings necessary for panels installation. If possible initial gaps between the panels and adsorbers shell will be shown.
✓ All dimensional checks reports made by the suppliers for adsorbers, nozzles, annular chambers, Center Pipe, panels, beams, etc …
✓ All dimensions checks reports, between adsorbers shell and Center Pipe shell. The check to be done at minimum 6 locations equally spaced from bottom to top and taken at mid beds.
✓ Initial centering report of the Center Pipe with the center of P/A inlet nozzle.
✓ All facilities and site arrangements lay out and dimensions