MAHARASHTRA NATURAL GAS LIMITED

Transcription

1 Replies to Queries of the Bidders Date: SUB: Replies to queries of the bidders for Tender for Procurement of 6 & 4 Coated Line Pipe for Sindhudurg, Ramanagara & Pune area for CGD Projects of MNGL, Pune REF: Bid Document No. MNGL/C&P/ /109 dated , Addendum I dated & Addendum II dated Dear Sir, Following are the replies to queries of the bidders. Kindly note the same. Sl. Bidder s Query / Clarification No. 1 Annexure-I to IFB : Bidder s Eligibility Criteria Clause No.2.0 (B) Delivery Schedule : Consignment to reach Warehouse within 16 weeks from the date of Purchase order it is practically not possible to deliver the material within 16 weeks. We request your good salves to amend the delivery schedule as with in 22 week from the date of Purchase order because the RAW Material suppliers taking minimum 10 to 12 weeks for delivery of Raw Material & after that manufacturing of pipes and Coating will take minimum 8-10 weeks. So please consider the above fact and amend the delivery schedule as Consignment to reach warehouse within 22 weeks from the date of Purchase order. 2 Cl. 2(B) DELIVERY SCHEDULE of Annexure I to IFB Page No. 6 of 208 Section IV Special Conditions of Contract Cl. 3.1 Page No. 93 of 208 Consignment to reach warehouse within 16 weeks from the date of Purchase Order. MNGL Reply Delivery Schedule is modified as under : Consignment to reach specified warehouse within 20 weeks from the date of Purchase Order. Delivery Schedule is modified as under : Consignment to reach specified warehouse within 20 weeks from the date of Purchase Order. Considering number of items & total quantity against this tender we would request you to amend the delivery period 24 weeks as completion within 16 weeks is not possible. 3 We request you please make changes in type bid from domestic to ICB along with authorization of mill to participate. This will certainly be a support to you in terms of cost saving and timely delivery as per your. Page 1 of 11

2 project requirement. 4 EMD : PART A SECTION I INVITATION FOR BIDS (IFB) V-A & V-B BID SECURITY VALIDITY: 6(SIX) months from bid due date. Please confirm EMD (BG) already prepared as per earlier submission / due date of tender shall be valid in case of extension of tender submission date. 5 Clause 1.1 of Client Spec Page No 109 of 208 Client specification is based on API 5L 43th & 44th editions As the latest edition of API 5L (45th edition) is already effective from July 1, 2013, and also it is a mandatory requirement of API 5L to follow the latest edition. Hence we wish to follow the latest edition of API 5L i.e. 45th. Kindly conform. Confirmed 45 th edition of API 5 L will be followed however stringent conditions of API 43 rd Edition /Technical specification shall be govern 6 Clause 5.4 of Client Spec Page No 111 of 208 For Welded Pipes, the pipes shall be produced from plates / skelp which shall be quenched and tempered or controlled rolled or combined controlled rolled and accelerated cooled to impart uniformly fine ferritic grain structure to the finished steel. Other types of heat treatment shall be agreed upon between purchaser and Manufacturer. Steel shall be thermo mechanically rolled. Query 1 -For Welded Pipes, the pipes shall be produced from plates / skelp which shall be quenched and tempered or controlled rolled or combined controlled rolled and accelerated cooled to impart uniformly fine ferritic grain structure to the finished steel with delivery condition of thermo mechanically rolled as per table no 1 of API 5L 45th edition. Kindly confirm. Query 2- Steel shall be thermo mechanically rolled. Agreed- Already mentioned in tender 7 Clause (e) of Client Page no 114 of 208 Additionally, for pipes of all sizes and specified wall thicknesses, additional fracture (New) toughness requirements as per Supplementary Requirements SR Agreed Page 2 of 11

3 19 of API Spec. 5L and as modified in this specification shall be applicable for body, weld and heat affected zone. We understand that the minimum absorbed energy requirement and test temperature for CVN impact tests shall be as per Appendix F of technical spec MNGL/LINE-PIPE/TS/00 i.e. test temperature 0 C & average minimum absorbed energy for full size specimen shall be 41 J & individual value 33 J for longitudinal base samples for size up to DN 250 (10 ) Kindly confirm 8 Clause No of Client Page No 130 of 208 The reference (calibration) standard shall have the same specified diameter and thickness as the product being inspected and shall be of sufficient length to permit calibration of ultrasonic inspection equipment at the speed to be used in production. The reference standard shall also be of the same material type and have the same surface finish and heat treatment as the product to be inspected. It shall be free from discontinuities or other conditions producing indications that may interfere with detection of the reference reflectors. The reference standard shall contain notches (N5 or N10) or radially drilled holes (3.2mm). The Manufacturer may use a type of reference reflector not specified above provided he can demonstrate to Purchaser that the examination is at least as sensitive as prescribed in this specification. In such cases, the Manufacturer shall obtain approval from Purchaser. We understand that for HFW pipes, UT reference standard shall be as following. Please reconfirm. HFW weld seam: N10 notch Φ 6.35 mm x ½t FBH depth for either side of welded seam & Pipe end for lamination detection. Pipe body- 8 mm width X ½t Circumferential slot. 9 Cl. no Page No 134 of 208 A colour code band shall be marked on inside surface of finished pipe for identification of pipes of same diameter but different wall thickness, if applicable, as indicated in the Purchase Order. The colour code band Bidders understanding is correct Bidders understanding is correct Already mentioned in tender if applicable Page 3 of 11

4 shall be 50mm wide and shall be marked at a distance of 150mm from the pipe ends. Query -1 We understand, it shall not be applicable in this enquiry, there is only one thickness per size. Kindly Confirm. Query -2 Please provide the colour coding requirement. If any. 10 Clause Client Spec Page No 125 of 208 Dimensional Testing The measuring equipment requiring calibration or verification under the provisions of API 5L shall be calibrated with manual instruments at least once per operating shift (12 hours maximum). Such calibration records shall be furnished to Purchaser s Representative on request We shall follow the API (45th edition) requirements regarding to comply the calibration & verification frequency of instruments & equipment s. 11 S. No. 1C of Inspection & Test Plan- MNGL/LINE- Pipe/TS/00 Ultrasonic inspection required of coil/raw material for checking of lamination, internal imperfection. We shall do the pipe body ultrasonic testing with 100% minimum coverage area as an alternative of Coil UT for lamination after hydrostatic test. Kindly confirm 12 S. No. 6 & 2c Inspection & Test Page No 3 of 4 Destructive Testing: - Quantum of check: - Material specification, Reference Documents :- PR. We understand that quantum of check shall be as per technical specification MNGL/LINE-PIPE/TS/00 & API 5L 45th edition. Please confirm 13 Clause No. 2.0 of Client Spec MNGL/LINE-PIPE/TS/00 Page No 108 of 208 References BS 5996: Specification for the Acceptance Level for Internal Imperfectionin Steel Plate, Strip and Wide Flats based on Ultrasonic Testing. We understand, BS 5996 is no more referenced in API Agreed 45 th edition of API 5 L will be followed however stringent conditions of API 43 rd Edition /Technical specification shall be govern and acceptance criteria for NDT method must be as per API 5L Page 4 of 11

5 5L, 45th edition. We shall have to follow ISO respective part for different NDT methods and acceptance criteria as per API 5L. Please confirm. 14 Cl. No. 1.0 of Spec. No.: MNGL/PL COATING/TS/00 Page No 156 of Layer Side Extruded Polyethylene Coating conforming to DIN-30670, 1991 Bidder has considered the latest version DIN-30670, 2012 to be followed for 3LPE coating. Please confirm. 15 Cl. No. 2.0 (y) & of Spec. No.: MNGL/PL COATING/TS/00 Page No 158 of 208 CSA Z : External Fusion Bond Epoxy Coating for Steel Pipe Epoxy powder properties shall be as per CSA Z Bidder has considered the latest version CAN/CSA Z Please confirm. 16 Cl. No of Spec. No.: MNGL/PL COATING/TS/00 Page No 173 of 208 After the de-ionised water wash, the pipe shall be dried with dry air and preheated to a temperature of 65 C to 85 C. Bidder understands that after de-ionised water wash, the pipe shall be dried with dry air temperature 65 C to 85 C. 17 Annexure-I of Spec. No.: MNGL/PL COATING/TS/00 Page No 192 of 208 List of acceptable combination of 3LPE coating materials: PE compound: HE 3450 (Borealis) Bidder has considered approved material PE compound HE3450 (Borouge/Borealis) instead of HE3450 (Borealis). Please confirm 18 Cl. No. 6.0 (Table-2) of Technical input for 3-Layer side-extruded polyethylene coating of pipes Page No 198 of 208 Sr. Properties No. 7 Coating Resistivety Frequency (1) 2 Pipes 8 Heat Ageing 2 Pipes Applicable Requirement Para (e)(3) Para (f)(3) Already mentioned in in Cl.2.0 The edition enforces at the time of floating the enquiry shall be termed as latest edition Already mentioned in in Cl.2.0 Page no 156 The edition enforces at the time of floating the enquiry shall be termed as latest edition Agreed Page 5 of 11

6 9 Light Ageing 2 Pipes Para (g)(3) 1) Test frequency shall be as indicated in this table and the frequency indicated in the applicable paragraphs of the specific are not applicable. 2) Two tests each on the selected pipes i.e 30 days and 48 hours test shall be carried out on each test pipe. 3) Previously carried out tests in an independent laboratory of national / international Bidder intent to clarify that the following tests are the long term tests and shall be performed by coating material supplier. Test certificates shall be furnished for review and acceptance. 1. Coating resistivity 2. Heat ageing 3. Light ageing Please confirm. 19 Cl. No. 6.0 (Table-2) of Technical input for 3-Layer side-extruded polyethylene coating of pipes Page No 198 of 208 Test Frequency Table 2 Sr. No. Properties Frequency (1) Bond Strength 5 Pipes Para 10.5 Impact Strength 3 Pipes Para 10.6 Indentation hardness Elongation at Failure Cathodic Disbondment Degree of Cure Applicable Requirement 5 Pipes Para Pipes 2 Pipes 2 Pipes Para 5.3.3(d) & 7.5.2(d) Para 5.3.3(h) & 7.5.2(e)(2) Para 5.3.3(i) & Para 10.9(a) 1)Test frequency shall be as indicated in this table and the frequency indicated in the applicable paragraphs of the specific are not applicable. 2)Two tests each on the selected pipes i.e 30 days and 48 hours test shall be carried out on each test pipe. 3)Previously carried out tests in an independent laboratory of national / international Bidder understands that the test frequency specified in table -2 (Cl. No. 6.0 of Technical input for 3-Layer side- Page 6 of 11

7 extruded polyethylene coating of pipes) is applicable only for procedure qualification test (PQT). 20 Annexure-I to IFB : Bidder s Eligibility Criteria Clause No Page No 7 of 208 Qualification Criteria for Coating Work :- The proposed coating plant by the bidder for three layer side extruded PE (3 LPE) coating on bare line pipes shall have coated at least 40 km length of bare line pipes of outside diameter 6 or higher using three layers side extruded PE coating, during any of the last Five years reckoned from the submission date of Bidding Document Sir we have executed the 3LPE coating contract for large dia pipes and all PSU like IOCL and GAIL required the equivalent surface area of 3LPE Coating for BQC. So please amend this clause as Proposed coating plant by the Bidder for three-layer side extracted PE (3LPE) Coating on bare Pipes shall have coated at least 40 KM length or Equivalent surface area of dia 6 or higher using three layers side extruded PE coating, during any of the last 5 years instead of tender clause. Please confirm. 21 Procurement of Steel Plates/ Coils Clause 20.7 of SSC Pge No 100 of 208 (List of steel plate/ coil manufacturers are acceptable for the procurement of steel plates/ coils to be used in the manufacture of line pipes.) You are requested to incorporate the M/S Tata Steel Limited,Jamshedpur ( Up to API 5L X-60 for WT upto 9.35 mm ) as the same is already approved by Mecon delhi in the recent tender floated by Mecon,Delhi GAIL Gas Ltd vide Tender No 05/51/23TQ-TP-QQ/GAIL GAS/012A and SGL vide Tender No 05/51U999/SGL/012A (Copy Attached) 22 MNGL/LINE-PIPE/TS/00 Wall Thickness 6.4 mm. 6.4 mm thickness is non-standard size as per API 5L, hence API monogram shall not be applied on product. 23 Cl. no 7.4 Page No 119 of 208 Length All pipes shall be supplied with length between 11.5m and 12.5m. However, for test sampling pipe having length between 10.0 m and 11.5 m can also be accepted. The minimum average length of the entire Agreed Pls refere cl. No of special condition of the contract Necessary documentary evidence need to be furnished in order to consider non listed vender Page 7 of 11

8 order shall be 12.0m. API Spec. 5L Table-11 shall not be applicable. We propose for length between 10.0 to 11.5 m shall be 10% of ordered quantity including test sample pipe and defect cut pipes. Proposed average length shall be 11.8 m 24 Cl. no Page No 125 of 208 The test pressure for all sizes and grades of pipe shall be such that hoop stress (fibre stress) generated is at least 95% of SMYS, computed based on the formula mentioned in API Spec 5L para (Note 2) Para (Note 2) is deleted in 45 th edition of API 5L. Test pressure shall be as per 45th edition of API 5L. 25 Cl. No. 9.8 Page No 125 of 208 Non-Destructive Inspection Manufacturer shall comply with the provisions regarding inspection notice, plant access, compliance and rejection mentioned in Appendix H of API Spec 5L. Appendix H is deleted in 45th edition of API 5L. Nondestructive test shall be carried out as per API 5L. SPECIFICATION FOR 3-LAYER POLYETHYLENE COATING OF LINEPIPES SPECIFICATION NO.: MNGL/ PL COATING/TS/00 26 Cl. No. 4.2 Page No 159 of 208 The coating materials Manufacturer shall carry out tests for all properties specified in para and for each batch of epoxy, adhesive and polyethylene compound. Noted. The coating material manufacturer shall be mentioned all required test value / typical value in test certificate. 27 Cl. No 4.3 Page No 159 of 208 c) iv, Moisture content for Polyethylene Moisture Content shall not applicable to Polyethylene. We shall perform water absorption test as mentioned in table of cl. No of spec 28 Cl. No Page No 173 of 208 The ph of the pipe surface shall be determined both before and after the deionisedwater rinse initially on each pipe and in case of consistent results, the frequency may be relaxed to once per hour at the discretion of COMPANY Representative. 45 th edition of API 5 L will be followed however stringent conditions of API 43 rd Edition /Technical specification shall be govern 45 th edition of API 5 L will be followed however stringent conditions of API 43 rd Edition /Technical specification shall be govern Agreed During the PQT pipes, ph will be measured for each pipe. In regular production it may reduce to one hour in Page 8 of 11

9 place of each pipe. 29 Cl no. 8.7 Page No 174 of 208 Surface of pipe after abrasive blast cleaning shall have an anchor pattern of 40 to 90 microns(rz). This shall be measured for each pipe by a suitable instrument such as surface profile depth gauge / digital roughness gauge. We proposed roughness 40 to 90 as per DIN Roughness shall be measured by digital roughness gauge every hour. 30 Cl No Page No 175 of 208 Following completion of abrasive blast cleaning, all pipe surface shall be chemically Pre-treated with a 10% +/- 2% strength chromate solution. We shall maintain max. 10% or 10+/- 2% as per raw material manufacturer recommendation. 31 Cl No Page No 176 of 208 The concentration shall be checked at the makeup of each. Fresh solution and once per hour, using a method approved by the chemical manufacturer We propose for each Fresh solution and once per shift 32 Cl no Page No 180 of 208 The extrusion temperatures of the adhesive and polyethylene shall be continuously recorded / recorded once per hour. The monitoring instruments shall be independent of the temperature control equipment. The instruments shall be calibrated prior to start of each shift We proposed that such instrument calibrated in specialized equip laboratory, we proposed review of outside lab calibration certificated and adhesive and polyethylene temperature once per hour. 33 Cl No 10.3 Page No 181 of 208 a. The coating thickness shall be determined by taking at least 10 measurements at locations uniformly distributed over the length and periphery of each pipe. of each pipe. Already mentioned in tender Already mentioned in tender Already mentioned in tender Page 9 of 11

10 During the PQT pipes, thickness will be measured for each pipe. After consistence result of regular production, it may reduce to one hour in place of each pipe 34 Cl No 12.0 Page No 188 and 189 of 208 Repair materials clearly establishing the compliance of the repair materials with the applicable coating requirements indicated in this specification Irrespective of type of repair, the maximum numbers of repair of coating shall be as follows: We understand its compliance is not for properties described on this specification cl no Because repair material properties are different than plant applied 3LPE coating. If there is any other requirement for repair material, please specify We understand that repair generated due to tests is not covered this criteria. 35 Test Frequency Page No 198 of 208 Table 2 Frequency (1) We understand that this frequency is for PQT. 36 Test Frequency Table 2 page No 198 of 208 Sl no. 5 Cathodic Disbondment Test frequency: 2 Pipes We propose to perform 1 pipe two test as applicable specification. 37 Clause 7.3 Page No. 119 of 208 The tolerances on specified wall thickness shall be (+)15 percent and (-)0.0 percent. However, in case of EW Pipes specified wall thickness tolerance upto (+)15 percent for a distance of 25 mm on either side of longitudinal weld seam is also acceptable. However, for seamless pipes only, wall thickness tolerance upto (+)20% (-)0 percent is acceptable. API Spec. 5L Table 9 stands cancelled. Wall thickness measurements shall be recorded at least 3 times per operating shift (12 hours maximum). Bidders understanding is correct Bidders understanding is correct Wall thickness tolerance required % in place of 20 % Page 10 of 11

11 Page No 123 of 208 Heat Analyses Where the steel mill is not a part of an integrated pipe mill, heat analysis shall be reported by the Manufacturer prior to start of production. We shall be provided raw material test certificate (Billet TC) for TPIA review due to continuous production we shall not provide heat details prior to production & Page No 123 & 124 of 208 Product Analyses Two pipes per inspection lot shall be analyzed. Inspection lot shall be 100 pipes per heat. Pipes selected shall be such that one at the beginning of the heat and one at the end of the heat is also represented Two sample per heat/ size shall be analyzed for product testing in place of two sample per pipes page No 123 of 208 Tensile Testing Frequency Tensile test shall be performed on samples taken from two pipes per inspection lot. Inspection lot shall be 100 pipes per heat. API Spec. Table 13 stands modified accordingly One sample per heat / size/lot shall be analyzed for tensile testing in place of two sample per 100 pipes MNGL/Line-Pipe /TS/ of 208 Hydrostatic Test Requirement Test pressure shall be held for a minimum period of 15 seconds for all sizes and grades of pipes. Bidders understanding Is correct it is two sample per inspection lot of 100 pipes to be taken for inspection & Pipes selected shall be such that one at the beginning of the heat one at the end of the heat Please submit the signed & stamped copy of Replies to Queries of the Bidders along with tender document with your techno-commercial offer as a token of acceptance. All the others terms and conditions of the bid documents are unchanged. With regards. Ganesh Said Sr. Manager (C&P) Page 11 of 11