1. PURPOSE
1.1 This engineering specification describes and covers the minimum requirements for vessel-related activities for the mechanical contractor.
- SCOPE
2.1 This specification applies to pressure vessels, columns, shop-fabricated storage tanks, heat exchangers, and vaporisers. This specification covers the erection of mechanical fabricated equipment onto prepared foundations, supply and drilling of holding down bolts, shimming and grouting of equipment, off-loading and storage of equipment, erection of ladders and platforms, pressure testing and nondestructive examination of equipment, application of thermal or acoustic insulation, cleaning, touch-up painting, charging of equipment with adsorbent/catalyst materials or fluids, and maintaining QA documentation and final construction dossiers. This document shall be read in conjunction with the mechanical contract and its attachments.
- RELATED DOCUMENTS
3.1 Company Engineering Documents
Worldwide:
Mineral Wool for Cold Box Insulation
Packing Process Equipment Jackets with Mineral Wool (Rock Wool)
Removal Procedure for Welded Shipping/Test Closures – Balloon Method
Loading Horizontal or Vertical Air Separation Plant Adsorber Vessels
Handling Brazed Core Extended Surface Heat Exchangers
Painting and Corrosion Protection of New Construction for Design Temperature to 649°C (1200°F)
Standard Clean (Class SC) Inspection and Acceptance Requirements
Process Clean (Class B) Inspection and Acceptance Requirements
Oxygen Clean (Class AA) Inspection and Acceptance Requirements
Cellular Glass Thermal Insulation System for Cold and Cryogenic Piping and Equipment Material Symbol C
Installation of Multi-Layer Thermal Insulation of Cryogenic Piping with Cellular Glass Symbol C1
Installation of Single-Layer Thermal Insulation of Cold Piping With Cellular Glass Symbol C4
PIR (Polyisocyanurate Foam) Thermal Insulation System for Cold and Cryogenic Piping and Equipment Material Symbol P
Installation of Multi-Layer Thermal Insulation of Cryogenic Piping with PIR (Polyisocyanurate foam) Symbol P1
Installation of Single-Layer Thermal Insulation of Cold Piping and Equipment With PIR (Polyisocyanurate Foam) Symbol P4
Mineral Fiber/Calcium Silicate Thermal Insulation System for High Temperature Piping and Equipment, Material Symbol M
Installation of Single-Layer Thermal and Acoustic Insulation of Dual and Low Temperature Piping and Equipment With Mineral Fiber, Symbols N2, N3, N4, N5, V6, and X6
Mineral Fiber Acoustic Insulation System for Piping and Equipment, Material Symbols T, V, X, and Y
Installation of Multi-Layer Acoustic Insulation System of Piping and Equipment With Mineral Fiber, Symbols T6 and Y6
Mineral Fiber Thermal Insulation System for Hot Piping and Equipment, Material Symbol F
Hydrostatic Testing of Stainless Steel and Nickel Alloy Equipment
Grouting of Equipment and Structures
Projects:
Mechanical Contract and its Attachments
Project Process and Instrumentation Diagrams (P&IDs) Project Piping Specification
3.2 British Standards Institution (BSI)
BS 3692 Specification for ISO metric precision hexagon bolts, screws and nuts. Metric units
BS 4190 Specification for ISO metric black hexagon bolts, screws and nuts
- EXTENT OF SUPPLY
4.1 The contractor is responsible for the supply of all the necessary labour, storage materials, supervision, plant equipment, consumables, scaffolding, craneage, transportation, tools, and materials associated with the storage and complete installation of the fabricated equipment listed in the mechanical contract. This document is intended to specify the minimum requirements for each type of equipment listed herein and is not intended to provide a definitive list of the actual equipment to be installed on any given project. The mechanical contract and P&IDs shall be referred to for clarification of the actual equipment requiring installation.
- GENERAL REQUIREMENTS
5.1 The contractor shall take all necessary precautions and measures to protect the equipment from damage caused during off-loading, storing, and installation.
5.2 The contractor shall receive all “free-issue” equipment and materials that have been supplied by Company and shall off-load and store as required.
5.3 On receipt of items under vacuum/pressure, the contractor shall check the indicated level of vacuum/pressure and check against the shipping note/GA drawing. The contractor shall notify the Company representative prior to the removal of any nozzle blanks or if the level of vacuum/pressure changes at any time. Seals on such equipment shall be broken in sufficient time to enable witness and/or inspection of the equipment prior to piping up. Equipment found to be soiled during erection or storage shall be re-cleaned at the contractor’s expense.
5.4 All bulk desiccant and adsorbent materials shall be stored indoors in a dry place and shall be covered with tarpaulin sheeting.
5.5 Occasionally, equipment might be delivered with internal desiccant bags. All equipment shall be checked for warning notices (that should list the number of bags to be recovered). The contractor shall locate and remove all internal desiccant bags and offer them together with the warning label for the Company representative to inspect.
- LIFTING AND ERECTION
6.1 Prior to commencement of the erection work, the contractor shall conduct a detailed survey of the location, size, and elevation of the foundations, their levelness and alignment, and shall immediately report to the Company representative any instances where discrepancies occur. Lifting studies are required for all lifts of 20 tonnes and heavier, and these studies shall take into account all relevant aspects of space requirements, ground bearing capacity, and lifting beams (if required).
6.2 All craneage, chains, shackles, and other lifting devices shall have certification for safe and correct unloading, lifting, storage, or erection of equipment.
6.3 All lifting of equipment shall be carried out strictly in accordance with 4WCE-600500.
- ANCHORS AND GROUTING
7.1 Hold-down bolts shall be supplied by the contractor where specified. Nuts shall be supplied and installed by the contractor, including locking nuts for all foundation bolting.
7.2 Grouting materials shall be supplied by the contractor in accordance with 4ECE-M13. Company prefers the use of jacking bolts, but where shims are used, they shall be removed after grouting. Where shims are allowed to be retained by the Company representative, the shims shall be stainless steel.
7.3 Where anchor bolts are not supplied cast-in to the foundations, the mechanical contractor shall supply and install appropriate anchor bolts (e.g., “Hilti” type).
7.4 Anchor bolt nuts shall be tightened to the appropriate torque value specified in the following table. All anchor bolts shall be fitted with locknuts. Threads shall be lubricated with a Molybdenum disulphide based grease.
| Metric Bolt Size | Grade 4.6 (per BS 4190) Bolt Torque (Nm) Based on Allowable Bolt Stress of 96 MPa* | Grade 8.8 (per BS 3692) Bolt Torque (Nm) Based on Allowable Bolt Stress of 256 MPa* |
| M10 | 11 | 30 |
| M12 | 20 | 52 |
| M16 | 46 | 123 |
| M20 | 90 | 241 |
| M24 | 156 | 417 |
| M30 | 305 | 814 |
| M36 | 528 | 1407 |
| M42 | 838 | 2234 |
| M48 | 1251 | 3335 |
| M52 | 1590 | 4240 |
| M56 | 1986 | 5296 |
| M60 | 2443 | 6514 |
| M64 | 2965 | 7906 |
| M68 | 3556 | 9483 |
| *Note: Design allowable anchor bolt stress = 0.4Re (Re is the bold yield). Specified torque produces a bolt stress of 150% of design allowable (i.e. 0.6Re ) calculated using the “short” formula with the bolt friction factor = 0.1. | ||
7.5 The anchor bolts for vertical, heat exchanger brackets and at the “sliding saddle” of horizontal vessels and exchangers shall not be tight. To permit thermal movement, the nuts shall be tightened, then slackened by half a turn and locked.
- MODIFICATIONS TO VESSELS AND HEAT EXCHANGERS
8.1 No welding or modification work shall be performed on any equipment without the written authorisation of the Company representative. All welding shall be by qualified personnel and shall be supported by welding procedures that are qualified in accordance with the equipment design and fabrication code. All welding procedures and qualifications shall be available for inspection at the jobsite.
8.2 Where modifications are made to equipment on site with the agreement of the Company representative and approved/witnessed by the Third Party inspection body, the following documentation shall be supplied to Company for inclusion in the applicable equipment fabrication dossier:
- Qualified weld procedures
- Welders qualifications
- Test certificate (stamped by the Third Party Inspector)
- Material test certificates for all new materials/welding consumables
- Heat treatment procedure (if applicable)
- NDT reports
- As-built equipment drawings
- Design calculations (where applicable) approved by the Third Party Approval Body
- PAINTING AND GALVANIZING
9.1 All equipment shall be inspected for paint damage once installed. Chips, scratches, and other damaged areas shall be repaired in accordance with the applicable specification (e.g., 4WEQ-6804, or the Company client specification) as detailed in the mechanical contract. This shall also be performed for vessels that will be covered by insulation.
9.2 Platforms and ladders shall be supplied galvanised. Where galvanising has been damaged, the contractor shall perform the necessary repairs using an Company approved method. (The use of “Galvofroid” or equivalent is not permitted.)
10. PRESSURE TESTING
10.1 If the mechanical contractor wishes to pneumatically test a piping system through a vessel, unless otherwise agreed, the following shall be complied with:
- The proposed system pneumatic strength test pressure shall not exceed 90% of the vessel strength test pressure.
- The proposed system pneumatic leak test pressure shall not exceed 80% of the vessel strength test pressure.
Note: Failure to satisfy either of these conditions will necessitate that the vessel be isolated during the piping system pressure test.
10.2 The contractor shall not test through any vessels without obtaining prior written permission from the Company representative. Company will require a written procedure for review.
10.3 Where equipment requires a site pneumatic test, this shall be accomplished using dry, oil- free air or nitrogen (supplied by the contractor).
10.4 Where stainless steel equipment requires a site hydrostatic test or is tested as part of the piping system, this test shall meet the requirements of 4EEQ-C31. The contractor shall supply suitable test water.
10.5 All nuts, bolts, test blanks or caps, gaskets, temporary connections for filling, draining and venting, and any other materials required to perform pressure and or gas leak testing shall be supplied by the contractor.
11. INSULATION
11.1 Insulation shall be installed in accordance with the applicable Company specifications (e.g., 4WCE-600276, 4WCB-50002, 4WPI-INS006, 4WPI-INS007, 4WPI-INS008, 4WPI- INS001, 4WPI-INS003, 4WPI-INS009, 4WPI-INS012, 4WPI-INS014, 4WPI-INS019, as applicable).
12. PIPING CONNECTIONS
12.1 The mechanical contractor shall connect all vessel piping termination points to the purchaser’s pipework. This will require the removal of bolted or welded shipping blanks and the grinding of weld preparations as necessary.
12.2 When nozzle blinds have been removed, care shall be taken to keep the inside of the equipment clean and dry. This is critically important for cryogenic and oxygen clean equipment. Temporary nozzles or pipe caps shall be fitted whenever possible. The mechanical contractor is fully responsible for maintaining the equipment in its original cleanliness standard [e.g., 4WPI-SW70001: Standard Clean (Class SC), 4WPI- SW70002: Process Clean (Class B), or 4WPI-SW70003: Oxygen Clean (Class AA)]. Equipment that was delivered purged with dry gas (e.g., carbon steel equipment in oxygen service or cryogenic equipment) should generally have the purge reinstated as soon as possible after the piping has been connected.
12.3 The mechanical contractor shall supply all nuts, bolts, fasteners, studs, washers, and gaskets required at interfaces between vessels and the site erected piping in accordance with the project’s P&IDs and the piping specification.
12.4 All piping at vessel terminations shall be stress free. Piping shall not be hung from vessel’s flanges/nozzles to assist the installation. “Cold pull” shall not be used.
13. SPECIFIC EQUIPMENT REQUIREMENTS
13.1 The following paragraphs are intended to be checklists which detail minimum erection and installation requirements relating to specific types of equipment. All of the requirements listed under the applicable types of equipment shall be performed by the contractor unless specifically stated to the contrary in the mechanical contract.
13.2 Internally Coated Vessels
13.2.1 Some vessels, e.g. DCACs, hydrogen PSAs and molecular sieves, might be supplied with a “Plasite,” glass flake filled epoxy, vinyl ester (polyester), or aluminium arc-spray coating. In such cases, the contractor shall take care not to damage these coatings during installation. Any damage shall be repaired by the contractor to an agreed procedure.
13.3 Cryogenic Columns Not in Cold Boxes — The contractor shall:
13.3.1 Lift the complete column onto the prepared foundation.
13.3.2 Erect the column plumb per specification 4WMA-007018 and bolt it down per paragraph 7.4.
13.3.3 Grout foundations in accordance with 4ECE-M13.
13.3.4 Remove test blanks or shipping blinds and shall connect the appropriate instruments, piping, or valves. The contractor shall also reinstate the internal, purged atmosphere as soon as possible.
Note: When nozzle blinds have been removed, care shall be taken to keep the inside of the column clean and dry. Welded nozzle blinds shall be removed using inflatable dams per 4WCE-607001. Temporary nozzle or pipe caps shall be fitted whenever possible.
13.3.5 Fit V-wire filter screens to “dead space vents” and crevice “vents” of columns that contain internal reboiler condensers. (Note: These vents are normally shipped to the site blanked off in order to keep these internal areas of the column dry.)
13.3.6 Pack the inside of the column skirt with mineral wool in accordance with N02 and M07.
13.4 DCAC Vessels — The contractor shall:
13.4.1 Touch up any damaged paint areas in accordance with the project specification (e.g., 4WEQ-6804).
13.4.2 Lift the complete vessel onto the prepared foundation and bolt it down per paragraph 7.4.
13.4.3 Erect the vessel such that the tower’s deviation from the vertical in any plane does not exceed 0.1% of the tower tangent-to-tangent height (i.e., 1 mm deviation per 1 m of height).
13.4.4 Grout foundations in accordance with 4ECE-M13.
13.4.5 Install the internal demister, the support bed(s), the packing, and the bed limiter(s) and distributor(s), as required, following the internals supplier’s installation instructions. The installation shall be made available for inspection by Company.
13.4.6 Remove the test blanks or the shipping blinds and shall connect the appropriate instruments, piping, or valves.
13.4.7 Insulate the vessel in accordance with the project specification.
13.4.8 Erect free-issue ladders and platforms.
13.5 TSA (Molecular Sieve) Vessels (Horizontal) — The contractor shall:
13.5.1 Touch up any damaged paint areas in accordance with the project specification (e.g., 4WEQ-6804).
13.5.2 Lift the complete vessel onto the prepared foundation and bolt it down per paragraph 7.4.
13.5.3 Grout foundations in accordance with 4ECE-M13. The contractor shall also ensure that the sliding saddle is free to translate for horizontal vessels per paragraph 7.5.
13.5.4 Install internal screens, drain screens, and the internal filter in accordance with the project requirements and vessel drawings. The installation shall be made available for inspection by Company.
13.5.5 Remove the test blanks or the shipping blinds and shall connect the appropriate instruments, piping, and valves.
13.5.6 Install alumina, molecular sieve adsorbent, ceramic beads (where specified), and floating screens in accordance with the vessel drawings and 4WEQ-1012. The installation shall be made available for inspection by Company. The contractor shall also reinstate the internal, purged atmosphere if specified in the vessel loading specification.
13.5.7 Insulate the vessel in accordance with the project specification.
13.5.8 Erect free-issue ladders and platforms (where supplied).
13.6 PSA/TSA/VSA Vessels (Vertical) — The contractor shall:
13.6.1 Touch up any damaged paint areas in accordance with the project specification (e.g., 4WEQ-6804).
13.6.2 Lift the complete vessel onto the prepared foundation and bolt it down per paragraph 7.4.
13.6.3 Erect the vessel such that the tower’s deviation from the vertical in any plane does not exceed 0.3% of the tower tangent-to-tangent height (i.e., 3 mm deviation per 1 m of height).
13.6.4 Grout foundations in accordance with 4ECE-M13.
13.6.5 Install the internal screens (where required) and the internal filter in accordance with the project requirements and vessel drawings. The installation shall be made available for inspection by Company.
13.6.6 Remove the test blanks or the shipping blinds and shall connect the appropriate instruments, piping, and valves.
13.6.7 Install alumina, molecular sieve adsorbent, ceramic beads (where specified), and floating screens in accordance with the vessel drawings and 4WEQ-1012. The installation shall be made available for inspection by Company. The contractor shall also reinstate the internal, purged atmosphere if specified in the vessel loading specification.
13.6.8 Insulate the vessel in accordance with the project specification (where required).
13.6.9 Erect free-issue ladders and platforms (where supplied).
13.7 Other Vessels/Columns — The contractor shall:
13.7.1 Touch up any damaged paint areas in accordance with the project specification (e.g., 4WEQ-6804).
13.7.2 Lift the complete vessel onto the prepared foundation and bolt it down per paragraph 7.4.
13.7.3 Erect vertical vessels containing trays or packing such that the deviation from the vertical in any plane does not exceed 0.1% of the tower tangent-to-tangent height (i.e., 1 mm deviation per 1 m of height).
13.7.4 Erect vertical vessels not containing trays or packing such that the deviation from the vertical in any plane does not exceed 0.3% of the tower tangent-to-tangent height (i.e., 3 mm deviation per 1 m of height).
13.7.5 Install horizontal vessels with a 1:200 slope towards their drain nozzles, unless specified otherwise.
13.7.6 Grout foundations in accordance with 4ECE-M13. The contractor shall also ensure that the horizontal sliding saddles are free to translate per paragraph 7.5.
13.7.7 Install all internal bed limiters, packing, supports, screens, trays, demisters, adsorbent materials, catalyst and other internals shown on the vessel drawings or specified in the mechanical contract. The installation shall be made available for inspection by Company.
13.7.8 Remove the test blanks or the shipping blinds and shall connect the appropriate instruments, piping, or valves. The contractor shall reinstate the internal, purged atmosphere where required.
13.7.9 Make the vessel available for trace heating when required by the mechanical contract or the P&IDs.
13.7.10 Insulate the vessel in accordance with the project specification.
13.7.11 Erect free-issue ladders and platforms.
13.8 Shell And Tube Heat Exchangers — The contractor shall:
13.8.1 Touch up any damaged paint areas in accordance with the project specification (e.g., 4WEQ-6804).
13.8.2 Lift the complete exchanger onto the prepared foundation and bolt it down per paragraphs 7.4 and 7.5.
13.8.3 Install horizontal shell and tube exchangers with a 1:200 slope towards the drain, unless specified otherwise.
13.8.4 Grout foundations in accordance with 4ECE-M13. The contractor shall also ensure that sliding saddles are free to move for horizontal vessels per paragraph 7.5.
13.8.5 Remove the test blanks or the shipping blinds and shall connect the appropriate instruments, piping, or valves. The contractor shall also reinstate the internal, purged atmosphere where required.
13.8.6 Insulate the exchanger in accordance with the project specification.
13.9 Cryogenic Vaporisers (Shell And Tube) — The contractor shall:
13.9.1 Touch up any damaged paint areas in accordance with the project specification (e.g., 4WEQ-6804).
13.9.2 Lift the complete vaporiser onto the prepared foundation and bolt it down per paragraphs 7.4 and 7.5.
13.9.3 Install horizontal shell and tube exchangers with a 1:200 slope towards the drain, unless specified otherwise.
13.9.4 Grout foundations in accordance with 4ECE-M13. The contractor shall also ensure that sliding saddles are free to move per paragraph 7.5.
13.9.5 Remove the test blanks or the shipping blinds and shall connect the appropriate instruments, piping, or valves. The contractor shall also reinstate the internal, purged atmosphere where required.
13.9.6 Insulate the vessel in accordance with the project specification.
13.9.7 Prior to commissioning, charge steam-sparged, water bath vaporisers on the shell side with distilled water that has a maximum chloride content of 1ppm (by weight).
13.10 Ambair Vaporisers — The contractor shall:
13.10.1 Lift the complete vaporiser onto the prepared foundation and bolt it down per paragraph 7.4.
13.10.2 Erect the vaporiser such that the deviation from the vertical in any plane does not exceed 0.3% of the vaporiser’s tangent-to-tangent height (i.e., 3 mm deviation per 1 m of height).
13.10.3 Grout foundations in accordance with 4ECE-M13.
13.10.4 Remove the test blanks or the shipping blinds and shall connect the appropriate instruments, piping, or valves. The contractor shall also reinstate the internal, purged atmosphere as soon as possible.
13.11 Brazed Plate Fin Heat Exchangers
13.11.1 The contractor shall remove the dummy passage or the inactive zone plugs prior to the cold box’s erection (for completed cold boxes shipped to site) or remove the dummy passage plugs from the exchangers in site-built boxes prior to insulating the box. The heat exchanger supplier’s general assembly drawing will give the details and the locations of these plugs. The contractor shall perform the following based on the heat exchanger supplier’s practice:
- Sumitomo uses M6 metal plugs fitted with a tag indicating the need for them to be removed prior to insulation. The threaded hole resulting from the removed metal plug shall be plugged with a small quantity of rock wool.
- Chart might use tape or 3/8″ NPT metal plugs to seal inactive zones for transport/storage. The resulting threaded hole shall be plugged with a small quantity of rock wool.
- Five use yellow plastic caps to seal inactive zones – these should be removed.
- Zhongtai normally seal inactive areas with aluminium tape which should be removed.
13.11.2 Handling and storage of brazed plate heat exchangers at site shall be in accordance with the requirements of 4WEQ-1402
13.11.3 The fixing bolts of brazed plate heat exchangers shall be tightened finger tight. Double nuts, thread peening, or tack welding shall be used to lock the nuts and prevent them from working loose. Where bolts are used, they shall be installed head upwards so that they remain in place should the nuts become detached in service. All bolting shall be austenitic stainless steel.
Note: Oversize or slotted holes will be provided in the exchanger support bracket in order to accommodate thermal expansion and contraction of the core. After assembly, the minimum clearance between bolt and hole edge shall be 3.5 mm per 1 m of pitch between exchanger support brackets. The contractor shall ensure that the oversize washers supplied do not restrict this movement.
13.11.4 Where low friction pads under the exchanger support brackets have been specified, the pads shall extend over the full face of the bracket and shall be held in place by at least two bolts.
13.11.5 Exchangers shall be installed in site-built boxes such that their deviation from the vertical in any plane does not exceed the lower of 0.5 degrees or 15 mm over the exchanger length. Note: Tighter tolerances might be required for critical applications; see the project drawings.
13.12 Waste Chiller Towers
13.12.1 For shop-built [metal or Glass Fibre Reinforced (GRP)] Waste Chiller Towers, the contractor shall:
- Touch up any damaged paint areas in accordance with the project specification (e.g., 4WEQ-6804).
- Lift the complete vessel onto prepared foundation and bolt it down per paragraph
7.4. Note: GRP towers may be delivered in sections; the mechanical contractor is responsible for bolting together of the sections.
- Erect the tower such that the tower’s deviation from the vertical in any plane does not exceed 0.1% of the tower’s tangent-to-tangent height (i.e., 1 mm deviation per 1 m of height).
- Grout foundations in accordance with4ECE-M13.
- Remove the test blanks or the shipping blinds.
13.12.2 For site (concrete) or shop-built (metal or GRP) Waste Chiller Towers, the contractor shall:
- Install the internal demister, the support bed(s), the packing, and the bed limiter(s) and distributor(s) as required following the internals supplier’s installation instructions. The installation shall be made available for inspection by Company.
- Connect the appropriate instruments, piping, or valves.
- Erect free-issue ladders and platforms.
13.12.3 Additional care shall be taken with GRP towers owing to the strain sensitive nature of the material. All connections to nozzles shall be stress free, and the flange bolting shall be torqued in accordance with the supplier’s recommendations.