STANDARD SPECIFICATIONS. Followings have been covered in this section. The work is to be carried based on the standard specifications:

Transcription

1 STANDARD SPECIFICATIONS APPENDIX -3 Followings have been covered in this section. The work is to be carried based on the standard specifications: 1) Standard Specifications for Cold Insulation 2) Standard Specifications for Hot Insulation 3) Standard Specifications for Scaffolding STANDARD SPECIFICATIONS FOR COLD INSULATION 1.0 SCOPE:- This specification covers technical requirements and procedure for the application of self-extinguishing type insulation viz. expanded Polystyrene, rigid Polyurethane foam, Mineral wool etc. to Vessels, equipments, pumps and piping. 2.0 GENERAL REQUIREMENTS :- 2.1 Insulation shall be provided on piping, valves, pipe-fittings, vessels, exchangers and instruments, etc. containing fluids or vapour, for which it is necessary to :- a. Maintain low temperature for process control. b. Avoid surface condensation. 2.2 Protection of partially completed jobs:- All precautions shall be taken to ensure that each day s works is vapour sealed and cladded during erection and before being left over-night to prevent seepage of water into the materials and getting trapped. The system shall be protected by tarpaulin, water shed and other protective means All flanged joints, valves and pump-body shall be cold insulated with removable box type insulation. 2.4 Items not requiring insulation: - Bonnets of valves above gland packing, Name plates, stampings etc. of vessels & equipments. 2.5 Protection of Materials: - Insulation materials must be protested against any damage from delivery to finish cladding. Proper covering shall be provided and material shall never be stacked directly on soil. 3. INSULATION MATERIALS :- 3.1 General:- All materials used for insulation, fixing, sealing and protection shall be new and shall conform to the details given below and in clause 4.0. All insulating materials whether dry or wet shall be non-corrosive to the surfaces insulated. 3.2 Insulation material for insulating piping, vessels and exchangers in Cold and Dual temperature (Cold / Hot) service shall be Polyurethane foam for operating temperature range of C to C. 3.3 Foam of insulation shall be as follows:- Pipes upto 400 NB : Preformed pipe sections.

2 Pipes above 400 NB : Radial lags/preformed pipe segments Vessel shells : Radial lags. Vessel heads : Preformed sections or slabs contoured to the profile of vessel heads. Equipments : Radial logs or slabs as applicable to form contour of surface 3.4 Dimensions of preformed sections for piping insulation shall be defined by the outside diameter and insulation thickness. Tolerances for preformed sections shall be as under:- Outside diameter - 0%, + 5% Concentricity + 3% O. D. Bore Length, width and thickness of slabs + 2 mm + 2 mm 3.5 The material used shall not disintegrate, settle, and change its form of composition, in a detrimental way, of the service conditions. 3.6 The insulating material shall be chemically inert, moisture free, rot and vermin proof. 3.7 Preformed half sections and slabs shall be provided having their longitudinal and circumferential faces flat and smooth so as to mate with the mating sections at the whole face area. Ends of the preformed half sections shall be flat end perpendicular to the centre line. 3.8 The insulation material shall be self-extinguishing type, when tested by the method prescribed in Appendix-E of IS: PROPERTIES OF POLYURETHANE FOAM, MINERAL WOOL & PUF SUPPORT: The insulation material shall be rigid preformed cellular urethane foam of selfextinguishing type in accordance with ASTM C 591, Type II, Grade 2. The foam shall be formulated in such a way that it shall be of a self-extinguishing quality which under no circumstances shall cause fire to spread Density:- The density of finished foam shall be within 35.0 kg/m 3 to 39.9 kg/m 3 and shall be determined in accordance with ASTM C Thermal Conductivity:- Thermal conductivity of the Polyurethane foam slabs and sections shall not exceed K Cal / hr. M 0 C (0.16 BTU / ft 2 hr. 0 F / in) at 10 0 C mean temperature after ageing. The thermal conductivity shall be tested by the method prescribed in ASTM C Closed Cell Content:- The closed cell content shall be at least 95% by volume Mineral Wool: Material specification for mineral wool shall be as specified in Annexure- C. Density of mineral wool shall be kg/m 3 except for piping subjected to foot traffic where it shall be 150 kg/m 3.

3 3.11 PUF Support: Density of PUF support shall be 160 kg/m 3 and 300 kg/m 3 as per requirements in SOR. Shape shall be half round in two halves as per diameter of pipes. 4.0 ANCILLARY MATERIALS:- 4.1 Wire - netting, facing and binding wire:- Wire netting shall be galvanized 24 SWG x 20 mm to secure insulation blocks. Lacing and stitching wires shall be 20 and 22 SWG galvanized iron wire respectively. 4.2 Bands :- Bands shall be of Aluminum, of dimensions 20 mm width x 24 SWG, unless specified otherwise. 4.3 Adhesives: - The adhesive to be used for banding Polyurethane sections shall be Foster Fire Resistive Adhesive In case of non-availability of Foster s adhesive, blown bitumen, type 85/25 conforming to IS:702 shall be used as an alternative. 4.4 Vapour Seal :- The vapour seal for Polyurethane insulation shall be Foster Fire Retardant Mastic or equal. In case of non-availability of Foster s mastic, Bitumen Emulsion mastic Insulkote Grade T-12 or equivalent shall be used as an alternative. 4.5 Filler Material For Polyurethane :- Polyurethane foam dust or Mineral Wool mixed with specified adhesives shall be packed tightly so as to fill all irregular voids and at contraction joints For Mineral Wool : Loose mineral wool shall be used to fill oil voids and surface irregularities and at contraction joints. 4.6 Joint Sealer : The joint sealer to be used for sealing Polyurethane insulation joints and at flashing of insulation shall be Foster Foam Seal Sealer For Polystyrene and mineral wool insulation, the adhesive specified shall be used to seal oil joints. 4.7 Glass Cloth : The glass cloth to be used for vapour barrier reinforcement, shall be open weave 10 mesh Glass Cloth having glass fibre thickness of 5 mils. 4.8 Aluminum sheets for cladding of Vapour barrier on the insulation shall be Aluminum sheet of Gauge 22 SWG. 4.9 Anti-Corrosive Paint: A primer coat of red oxide zinc chromate primer shall be applied on all carbon steel and alloy steel piping before application of cold insulation. Item made of stainless steel shall not be painted but shall be wrapped with 0.10mm aluminum foil before application of cold insulation Bituminized roofing felt:-bituminized self-finishing roofing felt shall conform to IS:1322, Type 3, Grade APPLICATION OF COLD INSULATION:- 5.1 GENERAL: - The following applies to all types of cold insulated equipment and piping Surface Preparation: - The surface of vessels, piping and valves etc. on which cold insulation is to be applied, shall be free of dust, loose paint or any other foreign matter. One coat of red oxide zinc chromate primer shall be applied on the CS/AS surfaces to be insulated and allowed to dry before application of insulation.

4 5.1.2 Vapour Barrier : A 3.0 mm ( wet ) thick coating of vapour seal mastic shall be applied to the surface of the insulation as soon as possible after erection, to reduce the time the insulation is exposed to the weather to a minimum. Whilst this coat is still wet, glass cloth shall be laid over the surface and embedded in the mastic. Care shall be taken to ensure that the glass cloth is laid smooth and free from wrinkles, and that no pockets of air are trapped beneath the surface. At junctions in the glass cloth, the overlap shall not be less than 75mm. A second 3mm thick coat of mastic shall be applied after approximately twelve hours. When dry, this coating shall be a minimum of 1.5 mm thick. Care must be taken, however to ensure that the individual coats are not greater than 3 mm (especially in corners), otherwise some cracking of dried coat may result. The mastic shall not be applied over wet insulation or until the adhesive is dry. During this drying time the insulation shall be protected from the weather by Alkothene film, tarpaulin or similar materials approved by the Engineer-in-Charge. Where joints have been left un-insulated, a complete vapour seal as specified above shall be applied to the exposed and of the insulation and flashed weather tight on to the metal Vapour barrier shall be protected by cladding with aluminum sheets. Joints in aluminum sheet shall be staggered and suitably sealed with an approved sealer. Aluminum cladding shall not be applied until the vapour barrier has completely dried and its solvents have dissipated. Self tapping screws shall not be used to secure aluminum cladding as they may puncture the vapour barrier Stainless Steel Piping & Equipments:- All pipes, vessels & equipments of stainless steel shall be wrapped with 0.1 mm thick aluminum foil with an overlap of 50 mm having barium chromate sealer interposed in the joint prior to application of insulation. Foil shall be secured in position by aluminum bands, taking every precaution to avoid formation of pin holes or cracking in the aluminum foil. Cladding shall be done after the insulation and vapour barrier exactly the same way as above. 5.2 APPLICATION ON VESSELS AND EQUIPMENTS: All surfaces shall be prepared / cleaned before application of insulation. Insulation radial lags / preformed sections of handy sizes shall be installed on the surfaces of vessels adhering to each other with applicable joint sealer and secured in position by G.I. wire netting and aluminum bands at an interval of 225 mm. In case of multilayer, the inner layer of insulation shall be bonded to the vessel with the applicable adhesive. Subsequent layers of insulation shall be bonded to the preceding layer with the applicable adhesive. All the layers except the final shall be secured in position by metallic bands at an interval of 225 mm while the final layer shall be first secured with G.I. wire net and then with metallic bands at an interval of 225 mm. Bands shall be staggered on successive layers. There shall be no through joints in the insulation Shell of Vertical Vessels: Slabs in handy sizes shall be applied resting onto the supports with joints tightly butted, staggered & adhering to each other with applicable adhesive and secured in position by circumferential metallic bands at a pitch of 225 mm Top heads of Vertical Vessels: Shaped insulation sections shall be installed on top head, bonded and butted tightly to each other. Insulation shall be held in position by making use of galvanized iron floating ring (25 mm X 0.6 mm) placed over the

5 insulation and positioned in the centre of the head so as not to touch the nozzle at the vertex. The insulation shall be held in position by use of radial metallic bands, one end of which shall be fastened to the floating ring and the other end shall be anchored to the band(s) placed around the cylindrical section close to the head Bottom heads of Vertical Vessels : In all the skirt supported vessels, insulation supports are provided inside the skirt. Floating ring and wire loops around the nozzles and bands shall be used to support downward facing of insulation. Such a floating ring shall be positioned centrally around the nozzle but over the insulation by radial bands anchored to the logging support angle ring fixed inside the skirt at a pitch of 300 mm ensured over the support angle ring Securing cladding on insulation: Aluminum band 12mm (min.) wide X 24 SWG thick shall be used. 5.3 APPLICATION ON PIPING : Piping surface shall be cleaned of loose rust mill scale, grease, dust or any other foreign contaminants The insulation shall be applied to pipes in half round sections in reasonable handty sizes. Where the insulation thickness is greater than 50mm or the metal temperature is below -40 Deg C, multilayer construction shall be followed with all the joints staggered in successive layers The inner layer of insulation shall be bonded to the piping with applicable adhesive. Subsequent layers of insulation shall be bonded to the preceding layers with the above adhesive. Joint sealer shall be applied to the ends and edges of all sections for sealing all longitudinal and circumferential joints. Adhesive shall be applied evenly and the half sections shall be closely butted to each other both longitudinally and circumferentially All the insulation layers except the final layer shall be secured in position by metallic bonds at an interval of 225mm while the final layer shall first be secured with GI wire netting and then with metallic bond at an interval of 225mm. Bonds shall be staggered on successive layers Insulation of piping shall be stopped short of flanges to allow for withdrawal of bolts. For fittings, the insulation shall be completed by applying cut segments at the same insulation sections used for pipes Flanges & Valves:-Removable covers shall be provided over all flanges and valves. Aluminum covers over the valves and flanges shall be fitted with quick release clips. This application shall be proposed for each case by the insulation contractor and approved by the Engineer-in-Charge. 5.4 PIPE SUPPORT: In all the supporting arrangements at both horizontal and vertical piping, dry hard PUF pipe support bearing blocks coated with fire retardant paint / mastic shall be used All finished insulated surface on all types of pipes, valves, strainers, flanges, equipments, pump body etc. shall be well covered as per standard practice with aluminium sheet of gauge 22 SWG.

6 5.5 ALUMINIUM CLADDING : PIPING Straight pipe shall have aluminum cladding, cut and machine rolled(approx. 1.0 mtr. Long) wrapped around, with min, 50 mm overlaps on both longitudinal and circumferential overlaps. All laps shall be arranged to shed water A single bead shall be made on all overlaps to ensure tight arrangement. Self tapping screws, at every 150mm shall be provided at all longitudinal overlaps for both horizontal and vertical piping The cladding shall be secured tightly around the insulated pipe and held in position with bands on a maximum 300 mm centre. One band shall locate in each circumferential lap and the distance between laps divided at equal band spacing. The band securing seal shall be kept neatly in line and positioned away from viewing angle as much as possible Vertical overlaps on vertical or near vertical piping shall be staggered to provide overlaps at North and South positions at alternate sections of coverings On vertical piping, the securing bands shall be supported with S clips or J clips fabricated out of the cladding material as per the requirement and instruction of EIC EQUIPMENTS : The cladding over the vertical vessel shells shall be constructed with corrugated sheet metal, unless otherwise specified The cladding shall be applied commencing at the bottom of the vessel. Each circumferential ring of the cladding shall be tensioned by means of tensioning bands until the final joint is screwed tight. S clips shall be used as sheeting support at unscrewed circumferential overlaps The cladding shall be held tight over the vessel insulation by means of circumferential bands and sealed. The bands shall be positioned at all horizontal overlaps and at 450 mm Centres. Bands shall be held at their relative positions with the help of J clips and be machine stretched and sealed to remove slack only. The bands which are not supported by J clips shall be held in position on cladding by providing pop rivets at every two meters centres The cladding shall be minimum overlap of one corrugation on vertical joints and 80 mm on horizontal joints. The overlaps shall be arranged to shed water all the times The heads of the vertical and horizontal vessels shall be fabricated out of flat sheet metal in an orange peel construction with all radial seams overlapping a minimum of 50 mm centres. All overlaps shall be ball swaged and be rendered water tight Projections from the heads shall be sealed using metal flashings, neatly cut to fit around the projections and extending above the shell insulation for a minimum of 80mm. The seal between the flashing and shell insulation shall be weather proofed with self taping screws and mastics For vertical vessels, the cladding shall be secured to support ring by bolting. In case bolts are not provided, same are to be provided by the contractor at 300 mm centre on angles provided at every 1175 centres vertically. Felt washer, aluminum washers and nut shall be supplied by the contractor for all bolted connections at shell & heads.

7 6.0 TABLE OF THICKNESSES FOR EXPANDED POLYURETHANE INSULATION Nom. Pipe Diameter in inch Thickness in Millimeters & below Nom. Pipe Diameter in inch Thickness in Millimeters V V E / E Other vessels & equipments as per SOR Notes :- 1. Thickness do not include finish thickness and most of the cases, would be applicable for new insulations. In case of repair/replacement of old insulations, the existing thickness shall be considered. 2. Maximum single layer insulation thickness - 50 mm. Wherever thickness exceeds 50 mm two layers of insulation shall be used. For higher thicknesses several layers shall be used. 7.0 MEASUREMENT OF INSULATION: Joint measurement shall be recorded over the finished insulated piping as per IS However, billing of insulation for inspection pockets shall be done separately as per SOR and it has no relation with piping measurement.

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9 STANDARD SPECIFICATION FOR HOT INSULATION. 1.0 GENERAL :- 1.1 This specification covers design and material requirements for above ground, external insulation of piping and valves operating between ambient temperature and C for the purpose of heat conservation, process stabilization, temperature maintenance, personnel protection and fire protection. Wherever necessary this specification indicates the basis for selecting a criterion This specification is suitable for use in outdoor service with normal process plant atmospheres. 2.0 MATERIAL AND SPECIFICATIONS:- 2.1 General : All material shall be of high quality and good appearance. This specification covers two materials - Rockwool & Glass Wool Insulation materials shall be of low chloride content, chemically inert, non-sulfurous, rot proof, vermin proof, impervious to hot water and steam, non-injurious to health and non-corrosive to steel and aluminum ( even if soaked in water at ambient temperatures for extended periods ) The use of insulation or finishing materials containing ASBESTOS in any form is not permitted. 2.2 INSULATION MATERIAL: Fibrous Material ( Rock and Glass Wool ) : Shall be a preformed insulation and shall be of long fibred rock or glass material processed from a molten state into fibrous form bonded with a binder and suitable for the intended operational temperature range from ambient to C. Slag wool is not acceptable Unless otherwise specified herein, insulation material shall strictly conform to all the requirements of quality standards listed below :- Preformed pipe insulation Mineral fibre block & board thermal insulation : IS 9842 ; Latest issue for piping & equipments. : IS : 8183 ; Latest issue Density : 140 to 150 kg/m3 ( Density shall be within this range and density test shall be as per IS:5688/IS:3144, Latest Issue. Moisture content } And moisture } absorption } Not more than 2% ( IS:3144 ) }

10 Incombustibility ( IS:3144) Incombustible; Loss in weight not more than 5%. Thermal Conductivity ( IS : 3346 ) :- Mean Temperature 0 C Thermal / Conductivity mw/cm 0 C Mean Temperature is [ ( Hot Face Temp. + Cold Face Temp. ) / 2 ] Sulpher Content (IS: 3144) : Not more than 0.6 percent Linear Shrinkage (IS:3144 ) : Not more than 2% when subjected to soaking conditions of soaking heat at the stated maximum temperature of use ( C ) for 24 hours. Heat Resistance (IS:3144) : When heated to max. temp. ( C ),sample shall maintain its general form and shall not suffer visible deformation of the fibrous structure. Recovery after compression :After compression to 75% of the original (IS: Appendix A ; thickness, recovery shall not be less than (IS:9842 Appendix A ) 90% of original thickness. Alkalinity (IS:8183 Appendix B ) : ph of the solution of the material shall be between 7.0 and IS:9842 Appendix B ) Chloride Content (IS:3144): Not to exceed 20 ppm 3.0 Ancillary Material 3.1 For securing fibrous insulation :- On Piping :- On Equipment:- Band, 24 SWG thick x 12mm ( min ) wide, Aluminum. Band, 24 SWG thick x 20mm ( min ) wide, Aluminum. 3.2 Screws required for metal jacket securement shall be cadmium plated steel self tapping type A No. 8 dia x 12 mm long to BS 4176 complete with neoprene washers under the head. 3.3 To ensure perfect water proofing, all the cladding joints shall be packed with sealing materials which may either be in the form of a elastomeric sealing compound or fibre based bituminous felt strips. 4.0 APPLICATION OF HOT INSULATION:- 4.1 General: The application methods, given in this Standard are general in nature. The Contractor is responsible for applying an insulating system that will provide satisfactory operational performance and the requirements given herein shall be regarded as the acceptable minimum. The Contractor shall carryout the work in

11 accordance with the best practices of insulation application with the minimum of waste and debris and the final job shall have a neat, efficient and workmanlike appearance The insulation Contractor shall only insulate those sections of the plant that has been specifically released for such work by the Engineer-in-Charge Surfaces to be insulated shall be thoroughly cleaned, dried and made free from loose scale, oil or grease. It shall be the Contractor s responsibility to remove loosely adhering scale and dirt before applying insulation The insulation contractor shall not carryout any welding or drilling on plant equipment and piping Insulation shall be finished, beveled and weather proofed at all terminal points where it is required to remove bolts etc. without damage to the insulation All projections, such as lifting lugs, trunnions and stiffeners on piping shall be insulated with the same thickness of insulation as specified for pipeline Double layer insulation shall be required when the insulation thickness is greater than 75 mm. Insulation installed in two or more layers shall be staggered joint construction and each layer shall be secured in place and details of securement shall be the same for each layer Wet or Damaged Insulation shall not be used under any Circumstances :- Insulation material to be applied shall not be kept over bare ground to avoid water absorption. Installed material awaiting its protective cover shall be adequately protected from damage, rain and contamination and shall be covered with cladding at a minimum loss of time A minimum clearance of 25 mm between outside surface of any insulation finish and adjacent equipment, pipe or structural members shall be maintained Mattress ( Fibrous insulation - Rock or Glass Wool ) shall be applied over the surface with joints tightly butted and laced together with 1 mm dia galvanized lacing wire Insulation Securement ( All insulation materials ) :- Each layer of insulation shall be secured firmly in place with at least 3 loops of binding wire / band, one loop to be placed not more than 75 mm from each end and at least one loop to be equally spaced between end loops, for each section. Binding wire shall be drawn about the insulation with ends tightly twisted together, bent under and pressed into the surface of insulation. Bands or wires in no case be spaced more than 200 mm apart. Each layer of insulation shall be secured by the same method as above All insulated finished surface on pipes, valves, flanges, equipments etc. shall be well covered as per standard practice with aluminium sheet of gauge 22 SWG Securing cladding on insulation: Cladding shall be carried as per the procedure specified in the cold insulation and as per the instruction of EIC. Aluminum band 12mm (min.) wide X 24 SWG thick shall be used for securing the cladding as indicated the Annexure -B. 5.0 MEASUREMENT OF INSULATION: Joint measurement shall be recorded over the finished insulated piping as per IS However, billing of insulation for inspection pockets shall be done separately as per SOR and it has no relation with piping measurement.

12 PROCEDURE FOR ERECTION OF SCAFFOLDING: A) SCAFFOLDING is to be made out of tubular structures (Standards scaffolding pipes of 40 mm dia in order to complete entire painting work safely. All the scaffolding material including necessary fittings, clamps, platforms has to be arranged by the contractor at his own cost. The engineer-in-charge may accept better scaffolding material/technique than that given here in case if the contractor prefer to provide. Proper approach ladder for climbing from bottom platform to top platform are to be erected for easy climbing. B) Height between two horizontal members (Pipes) of tubular structures should be 500 mm to 800 mm (Maximum) to have ease and safety of climbing up or down by the working and inspecting personnel. In special cases the height may have to be reduced if felt necessary by the engineer-in-charge of GAIL. Provision must be kept for the same. C) Working platform or stages are to be made by steel/aluminum perforated sheets or similar material and secured firmly. These platforms are to be provided at a vertical distances of about 1200 mm. Similar stages are to be made all around the structures, pipes and vessels etc. for cleaning, painting and inspection works. (D) (E) A clear Gap of mm should be maintained between the edge of scaffolding pipes and sidewall of any vessel. Wooden planks, Bamboo, coir ropes, nylon ropes, cotton or any combustible material should not be used for making scaffolding Removal: Scaffolding shall be removed after completion of all necessary works.