switches, socket outlets and other instruments shall be concealed in walls.
The installation instructions for surface and concealed conduits given in this section are also applicable to the installation of steel conduits and accessories.
32.5.4 Galvanized Iron Pipes
The galvanized iron (G.I) pipes shall be installed at a minimum depth of 900 mm measured from the top of pipes to finished ground level. The pipe shall be laid and checked for soundness before completion of civil works. The G.I. pipes at the entrance of the buildings shall be installed at locations as shown on the drawings.
At all joints the pipes shall be firmly screwed and cotton yarn with water-proof compound shall be used to make the joint water-proof.
At each termination, the pipe end shall have threads and socket screwed on thread for installing soft metal bush. The soft metal bush shall be of approved quality and shall be male type.
The installation of pipes shall be complete in all respects including its fixing at terminations before the work is started. All sharp edges and burrs shall be removed by using reamer or any approved device.
The pipe shall be checked before installation of cable for any obstruction. If found, it shall be cleared without damaging the installation. All pipe ends shall be plugged to prevent entry of water, rodents etc.
32.5.5 PVC Pipe & Accessories
Rigid PVC pipes shall be installed under roads, paved areas, at crossing with other services and at cable entering building as shown on the drawings. The depth of the pipe shall very according to the conditions at site, and approval of Engineer shall be obtained prior to installation. In general the pipes shall be installed underground at the following depths measured from the top of the pipe:
- Under roads/pavement : 900 mm below finished surface
- When crossing outer : 250/500 mm vertical/horizontal
services clearances with concrete cover.
The trench of required dimensions shall be excavated and the bottom of trench cleaned and leveled. A 75 mm bed of fine sand shall be provided over which the PVC pipes installed after proper alignment. Where two or more pipes are installed in the same trench the clearance between pipes shall not less than 50 mm. After laying of pipe the trench shall be backfilled with clean screened earth in layers of 75 mm, each layer properly tamped and compacted.
Where underground cables enter connection terminal boxes the PVC pipe shall be installed on surface by means of galvanized steel clamps at a maximum internal of 450 mm.
After installation, the ends of the pipe shall be plugged with material impervious to water and chemicals. All joints shall be sealed adequately to prevent entry of foreign elements.
The installation of pipes shall be completed in all respects including its fixing at terminations, before cabling work is stated. All sharp edges and burrs shall be removed by using reamer or any approved device. The pipe shall be through cleaned of dirt and dust from inside, the pipes shall be installed in proper coordination with other works.
32.6 Measurement and Payment 32.6.1 Measurement
Items covered under this section of technical specification will be measured in units specified in BOQ for the work satisfactorily completed as shown on the Drawing or as directed by the Engineer.
32.6.2 Payment
Payment will be made in accordance with the unit prices in the BOQ of various items in accordance with the specifications and shall constitute full compensation for furnishing all materials, equipment and labour and for performing all operations necessary to complete the work.
Monday, October 19, 2009
suit the site condition shall be made without any extra cost. Conduit ends pointing upwards or downwards shall be properly plugged in order to prevent the entry of foreign materials. All openings through which concrete may leak shall be carefully plugged and boxes shall be suitably protected against filling with concrete. At all terminations of conduit, sharp edges of conduit ends shall be prevented to avoid the cutting or damaging of wires or cables during pulling through the conduits.
Underflooor conduit shall be installed at a minimum depth of 2 inch from the finished floor level or as shown on the drawings. The conduits shall be installed empty, before finishing of floor or in RCC work, with an 18 SWG steel wire drawn through the conduit for pulling cable. No conduits shall be laid under floor in bathroom.
Wherever the conduit lengths cross the expansion joint either along the columns or slab, suitable arrangement shall be provided so that when the conduit lengths in the expansion joint are stressed, the conduit shall not be crack or break.
32.5.2 Surface Conduits
The surface conduits shall be installed where shown on drawings only. The conduits shall be installed parallel or perpendicular to the surface of wall, structural members, ceiling, etc., by means of steel saddles and clamps of approved design. The conduits shall be kept at least 150 mm away from parallel runs of flues, steam pipes and hot water pipes.
The saddles shall be installed on surface by means of nylon or wooden plugs and galvanized screws. Appropriate size of holes in structure shall be made by drilling, the thickness of saddles shall not be less than 6 mm and clamps shall be of 16 SWG sheet steel. The surface conduits shall be supported at a maximum of one metre spacing along horizontal and vertical runs. All accessories for complete installation of conduit system shall be provided by the Contractor. The pull boxes, etc. as stated for concealed conduits shall also be applicable for surface conduit system. The entire steel conduit system alongwith the accessories shall be painted with one coat of black enamel paint after installation.
32.5.3 Steel Conduits and Accessories
The steel conduits and accessories are required to be installed on surface or concealed as shown on the drawings. Wherever possible the conduits(s) shall run on ceiling/beams on the appropriate routes as approved by the Engineer. The conduit(s) down to switches, socket outlets and other instruments shall be concealed in walls.
Underflooor conduit shall be installed at a minimum depth of 2 inch from the finished floor level or as shown on the drawings. The conduits shall be installed empty, before finishing of floor or in RCC work, with an 18 SWG steel wire drawn through the conduit for pulling cable. No conduits shall be laid under floor in bathroom.
Wherever the conduit lengths cross the expansion joint either along the columns or slab, suitable arrangement shall be provided so that when the conduit lengths in the expansion joint are stressed, the conduit shall not be crack or break.
32.5.2 Surface Conduits
The surface conduits shall be installed where shown on drawings only. The conduits shall be installed parallel or perpendicular to the surface of wall, structural members, ceiling, etc., by means of steel saddles and clamps of approved design. The conduits shall be kept at least 150 mm away from parallel runs of flues, steam pipes and hot water pipes.
The saddles shall be installed on surface by means of nylon or wooden plugs and galvanized screws. Appropriate size of holes in structure shall be made by drilling, the thickness of saddles shall not be less than 6 mm and clamps shall be of 16 SWG sheet steel. The surface conduits shall be supported at a maximum of one metre spacing along horizontal and vertical runs. All accessories for complete installation of conduit system shall be provided by the Contractor. The pull boxes, etc. as stated for concealed conduits shall also be applicable for surface conduit system. The entire steel conduit system alongwith the accessories shall be painted with one coat of black enamel paint after installation.
32.5.3 Steel Conduits and Accessories
The steel conduits and accessories are required to be installed on surface or concealed as shown on the drawings. Wherever possible the conduits(s) shall run on ceiling/beams on the appropriate routes as approved by the Engineer. The conduit(s) down to switches, socket outlets and other instruments shall be concealed in walls.
movement of heavy duty vehicles such as trucks, cranes, fork-lift, etc. Where pipe changes direction, manufactured smooth bends shall be used.
Bending of pipes by heating or otherwise will be allowed in special cases only. Bending by heating shall be carried out by first filling the pipe with sand inside and then immediately removing the sand. The use of sharp 90 degree bends and tees will not be allowed. The bends shall conform to same specifications as given for PVC conduits. For jointing of pipe all precautions and procedures recommended by manufacturer shall be followed.
The pipe and accessories shall be of Nikasi, Beta Prince or approved equivalent.
32.5 Installation
32.5.1 Concealed Conduits
Where concealed conduit system is stated on drawings, the conduit shall be installed concealed in roof, wall, column, etc. Conduits shall be laid under floor only where specifically stated. The entire conduit system shall be installed and checked before wiring is carried out. Any obstruction found shall be cleared before the installation of cable.
When concealed, the conduit shall have a minimum of 32 mm cover of concrete measured from the top of conduit to finished surface. In the reinforced cement concrete (RCC) work the conduit shall be laid before pouring of concrete. Under no circumstances shall chases be made in the RCC structure for concealing conduit and accessories after pouring of concrete. The conduit shall be supported on top of bottom reinforcement of slab. All outlet boxes to be firmly supported and installed such that they finish flush with the soffit of slab or beam.
Where conduits have to be concealed in cement concrete (CC) work after concreting or in block masonry, chase shall be made with appropriate tools and shall not be made deeper than required. The conduit shall then be fixed firmly in the recess and covered with cement concrete mixture. The work of cutting in the cement concrete work or block masonry work shall be coordinated with the civil work. The Contractor shall obtain approval from the Engineer before starting chasing and cutting.
The termination of conduits at or near the equipment/switchboard is shown diagrammatically on the drawings. The exact locations of the termination shall be coordinated with the equipment/switchboard to be installed. Any extension of conduit to
Bending of pipes by heating or otherwise will be allowed in special cases only. Bending by heating shall be carried out by first filling the pipe with sand inside and then immediately removing the sand. The use of sharp 90 degree bends and tees will not be allowed. The bends shall conform to same specifications as given for PVC conduits. For jointing of pipe all precautions and procedures recommended by manufacturer shall be followed.
The pipe and accessories shall be of Nikasi, Beta Prince or approved equivalent.
32.5 Installation
32.5.1 Concealed Conduits
Where concealed conduit system is stated on drawings, the conduit shall be installed concealed in roof, wall, column, etc. Conduits shall be laid under floor only where specifically stated. The entire conduit system shall be installed and checked before wiring is carried out. Any obstruction found shall be cleared before the installation of cable.
When concealed, the conduit shall have a minimum of 32 mm cover of concrete measured from the top of conduit to finished surface. In the reinforced cement concrete (RCC) work the conduit shall be laid before pouring of concrete. Under no circumstances shall chases be made in the RCC structure for concealing conduit and accessories after pouring of concrete. The conduit shall be supported on top of bottom reinforcement of slab. All outlet boxes to be firmly supported and installed such that they finish flush with the soffit of slab or beam.
Where conduits have to be concealed in cement concrete (CC) work after concreting or in block masonry, chase shall be made with appropriate tools and shall not be made deeper than required. The conduit shall then be fixed firmly in the recess and covered with cement concrete mixture. The work of cutting in the cement concrete work or block masonry work shall be coordinated with the civil work. The Contractor shall obtain approval from the Engineer before starting chasing and cutting.
The termination of conduits at or near the equipment/switchboard is shown diagrammatically on the drawings. The exact locations of the termination shall be coordinated with the equipment/switchboard to be installed. Any extension of conduit to
number and size of cables and as approved by the Engineer shall be provided:
- Straight run without bend : Max. spacing 30 metres
- Run with one 90o bend : Max. spacing 20 metres
- Run with two 90o bend : Max. spacing 15 metres
?? Adaptable Boxes
Adaptable boxes shall also be made of 16 SWG sheet steel and painted and finished to the same quality as the Lighting distribution boards. The adaptable box shall preferably be fixed adjacent to the DB and have suitable dimensions to match the installation with DB. However, in any case, the depth of adaptable box shall be according to number and size of cables and conduits shall not be less than the following:
- Conduits upto 25 mm dia : Min. depth = 50 mm
- Conduits upto 38 mm dia : Min. depth = 65 mm
- Conduits upto 50 mm dia : Min. depth = 90 mm
- Conduits more than 50 mm dia : Min. depth = 2 x dia
32.4.3 Galvanized Iron (G.I.) Pipes and Accessories
The G.I. pipes shall be made of mild steel, galvanized inside and outside by hot-dip galvanizing process. The pipes shall be free from stain, burrs or any other defect. The accessories for G.I. Pipes such as sockets, bends, etc. shall be also galvanized inside and outside and of same quality and specifications as the pipes.
These pipes shall be installed for crossing of cables above nallas and culverts and at entry into building. The pipes and accessories shall be provided with one thick coat of bituminous paint on the outer surface prior to installation. All pipes shall be secured in position by means of galvanized clamps, supports, etc.
G.I. pipes as manufactured Karachi Pipe Mills Ltd., or approved equivalent shall be provided.
32.4.4 PVC Pipes and Accessories
The PVC pipe shall be rigid. All pipes shall be minimum Class ‘D’ (working pressure – 12 bar), unless otherwise stated on Drawings or Bill of Quantities. The buried PVC pipe should be able to withstand the external load acting upon it by continuous
- Straight run without bend : Max. spacing 30 metres
- Run with one 90o bend : Max. spacing 20 metres
- Run with two 90o bend : Max. spacing 15 metres
?? Adaptable Boxes
Adaptable boxes shall also be made of 16 SWG sheet steel and painted and finished to the same quality as the Lighting distribution boards. The adaptable box shall preferably be fixed adjacent to the DB and have suitable dimensions to match the installation with DB. However, in any case, the depth of adaptable box shall be according to number and size of cables and conduits shall not be less than the following:
- Conduits upto 25 mm dia : Min. depth = 50 mm
- Conduits upto 38 mm dia : Min. depth = 65 mm
- Conduits upto 50 mm dia : Min. depth = 90 mm
- Conduits more than 50 mm dia : Min. depth = 2 x dia
32.4.3 Galvanized Iron (G.I.) Pipes and Accessories
The G.I. pipes shall be made of mild steel, galvanized inside and outside by hot-dip galvanizing process. The pipes shall be free from stain, burrs or any other defect. The accessories for G.I. Pipes such as sockets, bends, etc. shall be also galvanized inside and outside and of same quality and specifications as the pipes.
These pipes shall be installed for crossing of cables above nallas and culverts and at entry into building. The pipes and accessories shall be provided with one thick coat of bituminous paint on the outer surface prior to installation. All pipes shall be secured in position by means of galvanized clamps, supports, etc.
G.I. pipes as manufactured Karachi Pipe Mills Ltd., or approved equivalent shall be provided.
32.4.4 PVC Pipes and Accessories
The PVC pipe shall be rigid. All pipes shall be minimum Class ‘D’ (working pressure – 12 bar), unless otherwise stated on Drawings or Bill of Quantities. The buried PVC pipe should be able to withstand the external load acting upon it by continuous
32.4 Material
32.4.1 PVC Conduits and Accessories
The PVC conduits and accessories for lighting and power circuits shall be furnished by the Contractor as shown in the drawings or given in BOQ. The PVC bends shall have enlarged ends to receive conduit without any reduction in the internal diameter at joint. Manufactured smooth bends shall be used where conduit changes direction. Bending of conduits by heating or otherwise will be allowed in special situations only, for which the consent of the Engineer shall be required. The use of sharp 90 degree bends and tees will not be allowed for concealed wiring.
The round PVC junction boxes for ceiling light or fan points shall have minimum dimensions of 63 mm diameter and depth. The junction boxes for wall light points shall have minimum dimensions of 63 mm diameter and 38 mm deep. Round junction boxes shall be provided with one piece PVC cover plate fixed to the box by means of brass screws.
The PVC conduits and accessories shall be of Galco, Beta, Prince brand or approved equivalent.
32.4.2 Inspection and Adaptable Boxes
Inspection/Pull boxes and adaptable boxes shall be provided in conduit runs wherever required to facilitate pulling operation. The drawings are diagrammatic and do not indicate the position and spacing of inspection/pull boxes or adaptable boxes. However, these shall meet the following requirements:
?? Inspection / Pull Boxes
The rectangular inspection/pull boxes shall be made of 16 SWG heavy gauge sheet steel of suitable design of receive conduits. The box shall be painted inside and outside with black enamel paint over a base coat of red oxide primer paint. The minimum length of the box shall not be less than four times the cable manufacturer recommended bending radius of the cable. All concealed type boxes shall have a white plastic sheet of appropriate size fixed to the box by means of galvanized screws.
If the spacing between the end points of conduit run with respect to bends exceeds the following, an inspection/pull box of suitable size according to the
32.4.1 PVC Conduits and Accessories
The PVC conduits and accessories for lighting and power circuits shall be furnished by the Contractor as shown in the drawings or given in BOQ. The PVC bends shall have enlarged ends to receive conduit without any reduction in the internal diameter at joint. Manufactured smooth bends shall be used where conduit changes direction. Bending of conduits by heating or otherwise will be allowed in special situations only, for which the consent of the Engineer shall be required. The use of sharp 90 degree bends and tees will not be allowed for concealed wiring.
The round PVC junction boxes for ceiling light or fan points shall have minimum dimensions of 63 mm diameter and depth. The junction boxes for wall light points shall have minimum dimensions of 63 mm diameter and 38 mm deep. Round junction boxes shall be provided with one piece PVC cover plate fixed to the box by means of brass screws.
The PVC conduits and accessories shall be of Galco, Beta, Prince brand or approved equivalent.
32.4.2 Inspection and Adaptable Boxes
Inspection/Pull boxes and adaptable boxes shall be provided in conduit runs wherever required to facilitate pulling operation. The drawings are diagrammatic and do not indicate the position and spacing of inspection/pull boxes or adaptable boxes. However, these shall meet the following requirements:
?? Inspection / Pull Boxes
The rectangular inspection/pull boxes shall be made of 16 SWG heavy gauge sheet steel of suitable design of receive conduits. The box shall be painted inside and outside with black enamel paint over a base coat of red oxide primer paint. The minimum length of the box shall not be less than four times the cable manufacturer recommended bending radius of the cable. All concealed type boxes shall have a white plastic sheet of appropriate size fixed to the box by means of galvanized screws.
If the spacing between the end points of conduit run with respect to bends exceeds the following, an inspection/pull box of suitable size according to the
Chapter – 32
CONDUITS AND PIPES
32.1 Scope of Work
The work under this section consists of supplying, installing and commissioning of all material and services of the complete Conduits and Pipes as specified herein and / or shown on Tender Drawings and stated in the Bill of Quantities.
The Contractor shall discuss the electrical layout with the Engineer and coordinate at Site with other services for exact route, location and position of the electrical lines. The conduits and pipes with accessories shall also comply with the General Specifications for Electrical Works, Section-8001 and with other relevant provisions of the Tender Documents.
32.2 General
The extent of works shown on the drawing does not indicate the exact position of conduits and pipes. The Contractor shall ensure exact location and route of conduit and pipes in accordance with other services drawings, as per site requirements and as directed by the Engineer.
The quality and material for the accessories of conduits and pipes such as sockets, elbows, bushing, bends, inspection/pull boxes, round boxes, etc., necessary for the completion shall be similar to that of conduits or pipes. All the accessories shall be supplied by the Contractor without any extra cost and deemed t have been included in the price of conduits/pipes.
32.3 Applicable Standard / Codes
The latest edition of the following standards and codes shall be applicable for the materials specified within the scope of this section:
BS 31 - Steel conduits and accessories
BS 4607 - PVC conduits and accessories
BS 3595 - PVC pipes and accessories
BS 1378 - Galvanized Iron pipes and accessories
CONDUITS AND PIPES
32.1 Scope of Work
The work under this section consists of supplying, installing and commissioning of all material and services of the complete Conduits and Pipes as specified herein and / or shown on Tender Drawings and stated in the Bill of Quantities.
The Contractor shall discuss the electrical layout with the Engineer and coordinate at Site with other services for exact route, location and position of the electrical lines. The conduits and pipes with accessories shall also comply with the General Specifications for Electrical Works, Section-8001 and with other relevant provisions of the Tender Documents.
32.2 General
The extent of works shown on the drawing does not indicate the exact position of conduits and pipes. The Contractor shall ensure exact location and route of conduit and pipes in accordance with other services drawings, as per site requirements and as directed by the Engineer.
The quality and material for the accessories of conduits and pipes such as sockets, elbows, bushing, bends, inspection/pull boxes, round boxes, etc., necessary for the completion shall be similar to that of conduits or pipes. All the accessories shall be supplied by the Contractor without any extra cost and deemed t have been included in the price of conduits/pipes.
32.3 Applicable Standard / Codes
The latest edition of the following standards and codes shall be applicable for the materials specified within the scope of this section:
BS 31 - Steel conduits and accessories
BS 4607 - PVC conduits and accessories
BS 3595 - PVC pipes and accessories
BS 1378 - Galvanized Iron pipes and accessories
40.2.3 Galvanized Iron (GI) Pipes and fittings
a. General: Galvanization shall conform to the requirement of BS 729. All threaded pipes and fittings shall have threads, in accordance with BS 21.
b. Pipes: The GI Pipe shall conform to the requirements of BS 1387: 1967. the Test pressure for all Classes (L, M and H) of GI Pipe shall be 700 psi.
c. Fitting: The material, wall thickness and galvanization quality, for the GI Fittings shall be same as that for the specified GI pipe.
40.2.4 Polyvinyl Chloride (PVC) pressure pipes and fittings:
Polyvinyl (PVC) pipes shall conform to the requirements of BS 3505:1968, for the specified class. The test and working pressures for various classes of pipes should be as under:
Class Test Pressure
Meter (Feet) Working pressure
Meter (Feet)
B 90 (300) 60 (200)
C 135 (450) 90 (300)
D 180 (600) 120 (400)
E 225 (750) 150 (500)
40.2.5 High Density Polyethylene (HDPE) Pipe & Fittings
All high density polyethylene pipes and fittings for installation at Chemical Dosing Facility shall be HDPE (High Density Polyethylene) conforming to ISO/ DIS 9969 with ring stiffness of 8kN/m2.
42.3 External Treatment for Piping
All underground GI and CI pipes and fittings shall be externally treated with one coat of hot applied bitumen (special industrial bitumen: 10 /20) and one layer of polythene sheet (500 microns) duly wrapped around.
42.4 VALVES AND APPURTENANCES
1. All valves shall be of same size as that of pipe line
2. Flow Control (Ball Type), check, float and foot valves of brass shall be installed on all the GI pipelines of water.
3. Cast Iron flanged gate valves (BS 5163, PN10 of approved make), metal seated wedge type with sealing ring and spindle of gunmetal shall be installed on all the wastewater and sludges pipe line.
4.Cast Iron (flanged) check valves (BS 5153, PN10 0f approved make) with swing type gun metal door shall be installed on all the wastewater and sludge pipelines.
All valves shall be tested to the appropriate test pressure at the manufacturer's works, and shall be supported by a test certificate from the manufacturer.
Markings of valves shall include the following:
• Manufacturing standard
• Manufacturer’s name or trademark
• Nominal diameter(s) (N.D) in mm
• Pressure rating in bars
• An individual serial number which relates directly to the manufacturer's test certificate
• Month and year of manufacture.
Position indicators shall be provided on all gate, butterfly and check valves.
The maximum effort required to operate the valve against the maximum unbalanced head applied at the circumference of the hand wheel or end of the tee-key shall not exceed 15 kN-m, where necessary gearing shall be provided as specified herein to achieve this.
Inspection, function test and strength test shall be made in accordance with DIN 3230 or approved equal.
The Contractor shall supply the original manufacturer's test certificate. The certificate shall relate to the individual number cast on each valve and shall give the date of test.
Valves shall be manufactured by an ISO 9000 series certified company who has had several years of experience in the manufacture of valves and shall have a fully equipped technical back-up and service facility. The manufacturer of the valves shall confirm the particular application of the valves for the intended use and shall provide a warranty of minimum 5 years on a replacement basis including labour and material at no extra cost. The warranty shall be issued directly to the Employer.
Before proceeding with any manufacturing, submit Shop Drawings for Engineer's prior written approval. Describe the items being submitted. Show dimensions, physical configurations, components and their composition, coating systems etc. Include material specification lists which shall summarize the specification features as called for in these Specifications and include such other necessary data as would provide a complete and adequate specification for re-ordering any spare part or an exact duplicate of the original from the manufacturer at some future date.
a. General: Galvanization shall conform to the requirement of BS 729. All threaded pipes and fittings shall have threads, in accordance with BS 21.
b. Pipes: The GI Pipe shall conform to the requirements of BS 1387: 1967. the Test pressure for all Classes (L, M and H) of GI Pipe shall be 700 psi.
c. Fitting: The material, wall thickness and galvanization quality, for the GI Fittings shall be same as that for the specified GI pipe.
40.2.4 Polyvinyl Chloride (PVC) pressure pipes and fittings:
Polyvinyl (PVC) pipes shall conform to the requirements of BS 3505:1968, for the specified class. The test and working pressures for various classes of pipes should be as under:
Class Test Pressure
Meter (Feet) Working pressure
Meter (Feet)
B 90 (300) 60 (200)
C 135 (450) 90 (300)
D 180 (600) 120 (400)
E 225 (750) 150 (500)
40.2.5 High Density Polyethylene (HDPE) Pipe & Fittings
All high density polyethylene pipes and fittings for installation at Chemical Dosing Facility shall be HDPE (High Density Polyethylene) conforming to ISO/ DIS 9969 with ring stiffness of 8kN/m2.
42.3 External Treatment for Piping
All underground GI and CI pipes and fittings shall be externally treated with one coat of hot applied bitumen (special industrial bitumen: 10 /20) and one layer of polythene sheet (500 microns) duly wrapped around.
42.4 VALVES AND APPURTENANCES
1. All valves shall be of same size as that of pipe line
2. Flow Control (Ball Type), check, float and foot valves of brass shall be installed on all the GI pipelines of water.
3. Cast Iron flanged gate valves (BS 5163, PN10 of approved make), metal seated wedge type with sealing ring and spindle of gunmetal shall be installed on all the wastewater and sludges pipe line.
4.Cast Iron (flanged) check valves (BS 5153, PN10 0f approved make) with swing type gun metal door shall be installed on all the wastewater and sludge pipelines.
All valves shall be tested to the appropriate test pressure at the manufacturer's works, and shall be supported by a test certificate from the manufacturer.
Markings of valves shall include the following:
• Manufacturing standard
• Manufacturer’s name or trademark
• Nominal diameter(s) (N.D) in mm
• Pressure rating in bars
• An individual serial number which relates directly to the manufacturer's test certificate
• Month and year of manufacture.
Position indicators shall be provided on all gate, butterfly and check valves.
The maximum effort required to operate the valve against the maximum unbalanced head applied at the circumference of the hand wheel or end of the tee-key shall not exceed 15 kN-m, where necessary gearing shall be provided as specified herein to achieve this.
Inspection, function test and strength test shall be made in accordance with DIN 3230 or approved equal.
The Contractor shall supply the original manufacturer's test certificate. The certificate shall relate to the individual number cast on each valve and shall give the date of test.
Valves shall be manufactured by an ISO 9000 series certified company who has had several years of experience in the manufacture of valves and shall have a fully equipped technical back-up and service facility. The manufacturer of the valves shall confirm the particular application of the valves for the intended use and shall provide a warranty of minimum 5 years on a replacement basis including labour and material at no extra cost. The warranty shall be issued directly to the Employer.
Before proceeding with any manufacturing, submit Shop Drawings for Engineer's prior written approval. Describe the items being submitted. Show dimensions, physical configurations, components and their composition, coating systems etc. Include material specification lists which shall summarize the specification features as called for in these Specifications and include such other necessary data as would provide a complete and adequate specification for re-ordering any spare part or an exact duplicate of the original from the manufacturer at some future date.
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