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3 Equipment Advisory Adv. No Supersedes: 0 Issue Date: Aug 19, 2015 File: Information Bulletin: Duct Spacers and Warning Boards for PVC Duct evision Note evised text in this advisory since the previous revision is shown with a vertical bar in the margin: changed or added text is underlined, and deleted text is crossed-out. evisions in the drawings are encircled with a cloud-shape, and a number in a small triangle indicates the revision edition. 1.0 Items Covered ES54 H1-01 UD AND UD INSTALLATIONS H1-07 INSTALLATION AT EDUCED DEPTH OF COVE H2-03 CONCETE ENCASEMENT 5" DUCT H4-01 DUCT CLEAANCES TO OTHE UTILITIES 2.0 Overview Distribution Standards are implementing a new construction practice for the assembly and installation of underground PVC duct for distribution infrastructure. This new construction practice will become mandatory when the revised ES54 Construction Standards are published. In the interim, all new projects shall follow this Advisory and the attached draft ES54 standards, effective August 3, Duct Spacers BC Hydro Catalogue ID : In accordance with the Class of Work Specifications, the assembly of the duct bank is left up to the BC Hydro contractor. They have the discretion to implement the most suitable and economical method of assembly. In some cases, contractors have installed manufactured duct spacers, resulting in superior assembly and better quality. More frequently, contractors will use 2"x4" or other pieces of lumber, or cut 3"dia PVC duct pieces to use as vertical spacers, which are then covered in concrete. For horizontal spacing, contractors place rakes and then remove them following the pour of the concrete layer. Warning Boards BC Hydro Catalogue ID : For mechanical protection and warning of direct buried feeder duct banks, or reduced depth of burial, the BC Hydro standard practice has been to install preservative-treated lumber boards and PVC warning tape above the duct bank. However, a lumber board s life expectancy is short, mechanical strength deteriorates quickly and a thin yellow warning tape is difficult to see when excavating. This Advisory is for the information of personnel working on BC Hydro s distribution equipment, and is not for public distribution. Page 1 of 4

4 Adv. No The new construction practice described herein is based on installing industry standard, impact-resistant polyethylene warning boards. New boards have been developed to perform both functions: mechanical protection for feeder direct buried duct banks, or reduced depth of burial, as well as a visible warning for a cable duct installation presenting an electrical hazard. For further reference on product evaluation and field trials, refer to ET051 ( 3.0 Action BC Hydro stores now carry PVC duct spacers and marker boards as standard stock items and respectively. Duct Spacers: For concrete-encased duct banks, BC Hydro designers shall follow the draft ES54 Section H standards and include new PVC type duct spacers. For customer installed concrete-encased duct banks, with customer supplied 5" PVC duct, the customer design shall show and the customer shall install the same IPEX PVC type duct spacer 5W20-2. Warning Boards: For direct-buried feeder duct banks or reduced depth of burial, BC Hydro designers shall follow the draft ES54 Section H standards, which show a warning board. For direct-buried UD and UD duct banks, warning boards may be installed as selected by the BC Hydro Designer at locations where a high safety hazard is identified by a risk assessment. For customer projects, warning boards can be obtained from LineStar Supply Inc. ( located at th St., Surrey, BC, V3W 7X4 or contact Tony Kuhlman Ph F C Class of Work Specifications 1322 and 1323 will be revised shortly to include duct spacers and warning boards for new construction projects. Projects currently in progress may proceed with a duct installation per the approved project design. This Advisory is for the information of personnel working on BC Hydro s distribution equipment, and is not for public distribution Page 2 of 4

5 Adv. No Figures Figure 1 IPEX 5W20-2 Duct Spacer for 5" dia. PVC Duct Figure 2 Warning board Figure 3 Direct burial This Advisory is for the information of personnel working on BC Hydro s distribution equipment, and is not for public distribution Page 3 of 4

6 Adv. No Figure 4 - Duct spacer locking tabs Figure 3-5" Duct spacers 5.0 Distribution Standards Contact Name: Mark Kelvin mark.kelvin@bchydro.com Phone #: Cell #: Date: Date: This Advisory is for the information of personnel working on BC Hydro's distribution equipment, and is not for public distribution Page 4 of 4

7 Warning tape or board Finished grade Warning Tape Finished grade Backfill Ducts Cover Ducts Backfill Cover Concrete Base Notes 1. Spacers shall not be used for direct buried ducts. 2. For direct-buried duct bank installation, place warning tape or polyethylene marker boards, catalogue ID , may be placed instead of treated lumber boards and marking tape at locations with high safety hazard as determined by the BCH Designer. eference Standards ES54 H0-02 ES54 H1-06 ES54 H2-01 ES54 H2-02 ES54 H2-03 ES54 H2-04 ES54 H3-01 ES54 H4-01 ES54 W1-01 Direct Buried Temporary trench shoring if required by contractor, remove before backfill Installation Location Min. Depth of Cover (mm) ailway 1680 MOTI oadway 1200 Other Areas 900 DAFT Duct General Notes Duct Entry Details 75 mm (3") Duct 100 mm (4") Duct 125 mm (5") Duct einforcing Window Opening In Underground Chambers Clearances to Other Utilities Base Preparation, Backfill Material Concrete Encased Base DESIGNED ECOMMENDED ACCEPTED GENEAL TENCHING DETAILS UD AND UD INSTALLATIONS EPLACES:DEC 2000 PAGE 1 ISSUED: JUN1980 OF 1 ES54 H1-01 3

8 6000 MAX Warning plates Manhole Minimum standard cover 300 < Minimum standard cover Minimum standard separation Other utilities or any other obstructions Ducts Elevation Alternative warning boards BChydro 3000 MAX Warning plates BCH Cat ID: BChydro BChydro Finished grade A _ BChydro Plan DAFT Detail 1 _ Sidewalk or road Aug 17, 15 Warning tape Manhole Warning plate ebar: 10M, L=900 mm Ducts concrete encased Detail 1 _ 70 Cover Section A _ 2 DESIGNED ECOMMENDED ACCEPTED EPLACES:AP 2003 ISSUED:AP 2003 GENEAL TENCHING DETAILS INSTALLATION AT EDUCED COVE DEPTH PAGE 1 OF 4 ES54 H

9 Warning plates Ducts Bridge abutment Manhole Bridge BChydro 6000 MAX Warning plates BCH Cat ID: BChydro BChydro Elevation A 1 DAFT BChydro Bridge Sidewalk Plan Installation in Bridge Deck Aug 17, 15 Manhole DESIGNED ECOMMENDED ACCEPTED EPLACES:AP 2003 ISSUED:AP 2003 GENEAL TENCHING DETAILS INSTALLATION AT EDUCED COVE DEPTH PAGE 2 OF 4 ES54 H

10 Notes 1. The minimum burial depth may be reduced when the minimum burial depth is impractical to avoid obstructions. 2. The reduced burial depth for PVC pipe shall be limited to 400 mm from the top surface of the duct bank to the finished grade. 3. The duct bank shall be concrete-encased along the entire length and reduced burial depth. 4. The maximum continuous length of the reduced burial depth shall not exceed 6 metres, and 5. Cast iron warning plates (BC Hydro Catalogue ID ) shall be installed within a finished grade at 3000 mm distance along the duct bank alignment at reduced burial depth, or 6. When installation of cast iron warning plates is impracticable, warning tape shall be replaced with warning boards (Cat ID ). Cast Iron Warning Plates Installation The warning plates are designed primarily to be installed within a concrete sidewalk. For installation within a roadway traffic surface, its replacement should be scheduled to follow the road maintenance and resurfacing program. Installation in Concrete The plates shall be cast in the concrete during the sidewalk construction as follows: 1. Install a rebar loop through each hole at the bottom side of the plate; 2. Tie the loops to other rebar in the concrete and secure plate in the proper position; 3. Ensure that the top surface of the plate is flush with or below the roadway surface; 4. Pour the concrete, and ensure minimum concrete cover below the rebar, and 5. Ensure that concrete does not cover the plate s top surface. Installation in Asphalt The asphalt surface of the roadway is cut for plates during pavement construction, and plates are epoxy cemented in the cut outs as follows: 1. Construct roadway surface with a minimum 75 mm asphalt pavement thickness at the warning plate s location. 2. Mark the locations of warning plates at the roadway surface along the centre line of the duct bank. a) Select locations with no deficiencies in the pavement. b) Avoid joints or cracks. c) Avoid pavement marking and line stripping. 3. Cut and grind the asphalt pavement surface at the marked locations, to a depth necessary to fully recess the warning plates in the roadway surface. a) Cut outs shall be completely dry and free of oil and foreign materials. b) Ensure that cut is within the pavement depth. c) Abandon overcut and select other location. DAFT Aug 17, 15 DESIGNED ECOMMENDED ACCEPTED EPLACES:AP 2003 ISSUED:AP 2003 GENEAL TENCHING DETAILS INSTALLATION AT EDUCED COVE DEPTH PAGE 3 OF 4 ES54 H

11 4. Test the plate fitting into the cut outs, and extend cut depth if necessary. a) Allow 3 mm clearance between pavement cut and plate for epoxy to bond properly. 5. Apply epoxy grout into cut-outs, in accordance with the manufacturer s recommendation. a) Epoxy shall comply with AASHTO M237 Type 4 6. Place warning plates into the epoxy field cut-outs a) Ensure that the top surface of the plate is flush with or below the roadway surface. b) Ensure epoxy overflows around the plate to seal the cut area. Add additional epoxy if needed. c) Ensure epoxy does not cover the plate. d) Protect plates from traffic during the epoxy curing time. DAFT Aug 17, 15 DESIGNED ECOMMENDED ACCEPTED EPLACES:AP 2003 ISSUED:AP 2003 GENEAL TENCHING DETAILS INSTALLATION AT EDUCED COVE DEPTH PAGE 4 OF 4 ES54 H

12 Notes Cover 560 Cover 750 DAFT 5" Ducts Jul 10, All cross-sections shown are for 125 mm (5") UD or feeder PVC duct, or rigid FE conduit. 2. All concrete-encased 5" duct banks shall be assembled using prefabricated duct spacers, catalogue ID For dimensional references and assembly details, refer to H for IPEX 5W20-2 spacers. Cover 950 DESIGNED ECOMMENDED ACCEPTED CONCETE ENCASEMENT 5 DUCT EPLACES:JUL 2002 PAGE 1 ISSUED:JUN 1980 OF 2 ES54 H

13 45 TOP VIEW Ø TYP eference Standards ES54 H2-04 ES54 H4-01 ES54 H1-02 ES54 H3-01 ES54 H1-01 ES54 H einforcing FONT VIEW 76 Clearances to Other Utilities TYP 5 Duct Spacer Catalogue ID DAFT SIDE VIEW Jul 10, 15 General Trenching Details: Feeders Window Opening in Underground Chambers General Trenching Details: UD and UD Installation Additions to Existing Duct Bank DESIGNED ECOMMENDED ACCEPTED CONCETE ENCASEMENT 5 DUCT EPLACES:JUL 2002 PAGE 2 ISSUED:JUN 1980 OF 2 ES54 H

14 DAFT Jul 10, 15 DESIGNED ECOMMENDED ACCEPTED DUCT CLEAANCES TO OTHE UTILITIES EPLACES:JUL 2002 PAGE 1 ISSUED:JUN 1980 OF 3 ES54 H

15 Finished grade Backfill Warning tape board 1/2 B Warning board - extend 1.2m each side from utility duct or pipe B Other utility ducts ducts or pipes B Minimum Clearances Typical Trench Cross Section Direct Buried Duct A minimum crossing separation is required from other utilities to provide clearance for repairs. DAFT Type of Pipe or Duct Direct-Buried Concrete-Encased BC Hydro Ducts BC Hydro Ducts* Clearances (mm) A B A B Telephone, cable TV or street lights Gas mains Water, oil pipelines, jet fuel lines, storm and sanitary sewers Steam pipe *Concrete encasement shall extend a minimum mm on each side of crossing. Horizontal clearances shall be maintained regardless of vertical clearances. Additional separation may be required where the cables are laid in the vicinity of other power cables or metal pipes, to maintain the specified heat ratings from these nearby services. A Jul 10, 15 DESIGNED ECOMMENDED ACCEPTED DUCT CLEAANCES TO OTHE UTILITIES EPLACES:JUL 2002 PAGE 2 ISSUED:JUN 1980 OF 3 ES54 H

16 Steam Pipes The clearances shown are for steam pipes of less than 225 mm nominal diameter. For larger diameter steam pipes, consult the BC Hydro designer. Steam pipes shall be insulated with a minimum of 75 mm thick foam glass pipe insulation, extending a minimum of 1200 mm on each side of the crossing. Where a steam pipe crosses below the BC Hydro duct bank, the backfill material between the steam pipe and BC Hydro duct bank shall have thermal resistivity. ailway Crossings At railway crossings, if the width of the duct bank exceeds 550 mm, additional strengthening may be required, as defined in CSA Standard C22.3 No. 7, Underground Systems. At railway crossings, the minimum concrete cover over ducts shall be 75 mm. educed Depth of Cover The minimum cover over the duct bank may be reduced, where absolutely necessary to overcome unavoidable site obstructions, subject to the following conditions: 1. The duct bank shall be concrete encased. 2. The continuous trench length at the reduced depth shall not exceed 6 metres, unless the ducts are installed in a bridge superstructure. 3. The design shall be approved by the BC Hydro Distribution Engineer. 4. eference Document CSA Standard C22.3 No. 7 "Underground Systems" eference Standards ES54 H1-02 ES54 H1-02 Cast iron warning plate Cat Id or warning boards Cat Id shall be placed over the length of reduced duct burial. DAFT General Trenching Details - Feeders General Trenching Details - UD and UD Jul 10, 15 DESIGNED ECOMMENDED ACCEPTED DUCT CLEAANCES TO OTHE UTILITIES EPLACES:JUL 2002 PAGE 3 ISSUED:JUN 1980 OF 3 ES54 H