161KV Steel Tubular Electric Pole Galvanized For Power Transmission Line

Product Specification

                                   161kv monopoles Galvanized Power transmission line Electrical Steel Tubular Tower Pole

Product Description

The products above are 1161kv monopoles Galvanized Power transmission line Electrical Steel Tubular Tower Pole  for   KPONE POWER EVACUATION PROJECT GHANA 

• SPECIAL TECHNICAL SPECIFICATIONS FOR MONOPOLE TRANSMISSION LINE

   

  • Foreword

   

  The present Paper shows possible line pre-design for the project, but any final design of the line for the project shall be carried on by specialized line designer and shall be fully and formally approved by GRIDCo. These specifications are supplementary to the transmission line specifications provided and should be read in conjunction with them.

   

  • Scope

   

  The project involves the construction of two double circuit transmission lines (approximately 7km and 5km respectively on self-supporting double circuit (DC) monopole transmission line towers using 1 x 604mm2 AAC HAWTHORN conductors with the monopole towers fitted with two optic fibre ground wire (OPGW) shieldwires.

   

  Bidders are encouraged to submit alternate specifications/drawings for self-supporting double circuit monopoles and shall price them accordingly for evaluation as alternates.

   

  C) Specification of steel monopoles: 1. Design conditions:

   

  Loading trees showing, for each load case, vertical, transversal and longitudinal loads applied to monopole shall be shall be as described in the technical specifications.

  Material partial safety factor γM are applied for calculation of cross-sections on yield stress of steel according to EN50341-1.

  Poles analysis shall include second order (or P - Λ ) analysis and checking of local buckling according to ASCE report N° 72. Calculation Note shall be issued and submitted to GRIDCo for approval.

  Poles are calculated with a limitation of deflection equal to 8 % of height under factored loads (cf EN 50341 §7.4.5.1.3).

   

  2. Materials:

  All materials shall be new and in accordance with relevant standards referred to within this specification.

   

  MATERIALS LIST
  ITEM	STANDARD	minimum YIELD STRESS Fy (Mpa)	minimum TENSILE STRESS Fu (Mpa)	OBSERVATION t = thickness
  Poles shaft and base plate and arms	EN 10.025 S355 J0 *	355 345 335 325	470-630 470-630 470-630 470-630	t = 16 16 < t = 40 40 < t = 63 63 < t = 80
  Anchor bolts	Cl 6-8 ISO 898	480	600

   

  (*) In accordance with NF A 35.503, Class 1 Chemical composition product analysis of Class 1 :

  Si	=	0.030	%
  Si + 2.5 P	=	0.090	%

   

  Mechanical characteristics and chemical composition of sheet steels shall be confirmed by Mill Test Certificates; these certificates shall comply to § 3.1 .B of EN 10204 / ISO 10474.

  3. Manufacturing:

   

  Sections of poles are made from sheets of steel, cut to trapezes, then cold formed to shape the twelve- sided regular polygonal cross section.

  Formed plate shall be bent to a radius sufficiently large so as not to produce cracking of the material.

   

  3.1. Welding

  The manufacturer shall be responsible for determining and for developing proper techniques to be used in the welding operations.

   

  All welding shall be performed by welders, welding operators and tackers qualified for the type of welding to be performed. Qualifications shall be in accordance with EN1090 or AWS D1. 1.

   

  All welding shall be performed in accordance with EN1090 EXC2 and EN1090 EXC3 for shaft to base flange, including procedure qualification.

   

  Welding shall be done by the shield metal-arc, gas shielded flux core, gas shield metal-arc or submerged-arc processes.

   

  3.1.1. Longitudinal Welds

  Longitudinal welds will have sixty (60 %) per cent penetration minimum except in slip joint area of female section where the penetration shall be 100%.

   

  3.1.2. Shaft to Base Plate Welds (if relevant)

  Shaft to flange plate welds shall be one hundred percent (100 %) penetration welds for base plate if shaft’s thickness is equal or over 6mm.

  If shaft’s thickness is less than 6mm, shaft to base plate welds will be fillet welds.

   

  3.1.3. Other Equipment

  These welds shall be fillet welds for all thicknesses according to drawings.

  
  3.2. Tolerances

  • Mean outside diameters, measured at slip joint level: ±1 % with ±2 mm minimum
  • Ovalization: the dimensional percentage noted for two measurements taken between two perpendicular diameters at slip joint level : less than 3 % [(Dmaxi-Dmini)/Dmaxi < 3 %]
  • Length of pole elements: - 25 mm / +75 mm
  • Members Straightness: less than 0.2 % of 1 meter member length (2 mm per meter)
  • Twisting: less than 1.5 degrees per 3 meters member length
  • Location of holes: ± 1 % on lengths indicated on our approval drawings

   

  3.3 Galvanization

   

  After the fabrication has been entirely completed, Steel Poles shall be hot dip galvanized. Double dipping shall not be allowed.

   

  All materials, except bolts, screws, nuts, shall be galvanized according to NF EN ISO 1461.

   

  All hollow members shall be galvanized both inside and outside surfaces. Nuts shall be retapped after galvanizing and then shall be suitably protected from rust by grease.

   

  4. Description:

   

  Galvanized STEEL POLES, uniformly tapered, 12 sided regular polygonal cross-section. The maximum length of one section shall be 12 meters.

   

  Each face shall be flat, without stiffeners except at load points.

   

  Steel Poles are designed for telescoping slip-fitted connections.

  Poles are designed with a minimum number of joints (one or two joint per pole). Pole joint shall be of telescoping type, welding or bolting shall not be employed.

   

  Slip joint length shall not be less than 1.5 times the major internal diameter of the upper element.

  A removable metallic pole cap shall be fitted on top of poles.

  The crossarms attached at the same level on opposite sides of the pole shall be symmetrical about the centerline of the pole and shall be such that each crossarm can be installed independently.

  The crossarms shall be connected to pole by mean of thru vangs, bolts and nuts. Cross-arms shall be straight and shall have a uniformly tapered 6 (eight) sided regular polygonal cross-section

  All poles shall be provided with one earthing point at a position approximately 50 cm above ground level.

   

  The access to top of pole is provided by steps or ladder and anti-falling device.

  An identification tag shall be nailed on poles; this tag shows:

  • Manufacturer name
  • Type and Length of pole
  • Year of manufacturing
  • Order reference

Drawings showing all details shall be prepared by Manufacturer and submitted to Customer for approval.

Factory launching and manufacturing shall not start prior to written approval of drawings.

5. Inspection and testing:

5.1. Check of dimensions

Regarding the requirement of dimensions, all sections and parts shall be checked according to the tolerances mentioned in relevant clause of this Technical Specification.

5.2. Check of welds

All welds will be visually checked. In doubtful areas, dye penetrant tests will be carried out acc. to class 2 of NF EN 1289 or magnetic particles tests acc. to class 2 of NF EN 1291.

5.3. Check of zinc thickness

Compliance to coating thickness requirements shall be checked with a magnetic thickness gauge acc. to NF EN ISO 1461.

5.4. Inspection file

All documents related to the job shall be filed and four copies y of the file shall be forwarded to GRIDCo prior to shipping.

This documentation shall include at least:

• Mill test certificates of steel plates and sheets
• Traceability data of material vs sections of poles
• Dimensional check report
• Welds checks report
• Zinc and painting thickness check report

ADDITIONAL INFORMATION

• The spans – normal, wind, weight, deviation angles/terminal angles for the monopole towers shall be the same as for the XX, YY and ZZ types as specified in the technical specifications. In addition, bidders are to include a terminal monopole tower with a deviation angle of 90⁰ using type ZZ design parameters.
• Technical specifications for XX, YY and ZZ lattice towers are to be used for the design of the monopoles (sag & tensions, load calculations).
• Polymeric insulators shall be used for the monopole towers. Length of insulator strings shall meet clearance and creepage requirements. Double insulator strings shall be used an all tension towers and for road/railway/river crossings. The polymer insulator strings shall come complete with the conductor tension and suspension sets, arcing horns etc
• The soil types are the same as those specified for the lattice towers in the technical specifications.
• Characteristics of 48 cores OPGW shall be used for the designs.
• The monopole towers shall be tested according to international standards.

Packaging & Shipping

 
We cover the top and bottom parts of the pole with a mat or straw bale in order to protect it from damage to the galvanized surface that may occur during transportation. Packaging can also be done according to clients’ requirements.
 
Process of Production

Verification of Materials → Cutting → Molding or Bending → Vertical Welding → Verification of Dimensions → Flange Welding → Hole Drilling → Calibration→ Deburring Process → Galvanizing, Powder Coating or Painting → Recalibration → Threading → Packaging

 
FAQ

 
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1. We will reply all your enquiries in 24 working hours.
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