Particular Specification - Part 40
Particular Specification for
Town Gas Installation
1. General Requirements
1.1 The Contractor shall be responsible for design, supply, installation, testing and commissioning of a complete Town Gas piping distribution system including pipework, valves, fittings and accessories after the Town Gas meters as specified in the Works Order to provide town gas supply for the town gas equipment provided by others and for the satisfactory operation of the equipment and system.
1.2 All installation, equipment, material and workmanship for town gas installation shall comply with all the requirements and practice of the Hong Kong and China Gas Co. Ltd. The Contractor shall ensure the compliance in all aspects and liaison with the Hong Kong and China Gas Co. Ltd. for the timely supply of town gas to the town gas equipment to meet the programme of the Works Order.
The town gas installation shall be carried out by competent persons. The Contractor may employ the approved town gas contractor of the Hong Kong and China Gas Co. Ltd. to carry out the town gas installation for the town gas equipments.
1.3 Samples Board
A sample board shall be submitted to the Architect for approval before the commencement of the installation work of each Works Order.
2. Specific Requirements
2.1 Material
Unless otherwise specified, pipework for town gas installation shall be galvanised mild steel tube to BS1387 heavy grade.
All pipeworks and fittings and other materials shall be supplied by a single manufacturer to ensure uniformity of standard and composition. All pipework and fittings delivered to site shall be coded at factory to identify different grades, materials, and manufacturers.
2.2 Pipe Installation
2.2.1 The Contractor shall install all pipework in an approved manner to meet the structural and architectural conditions. All pipework shall be installed plumb. Pipework shall be erected and secured as truly parallel with the building structure as reasonably practicable. Pipes shall run parallel to each other, and shall be clear of all adjacent surfaces and services to the approval of the Architect. All surface horizontal pipes shall be subject to spirit level tests.
No pipework and fitting installations are allowed to pass through beams, floor slabs etc., unless otherwise specified or indicated explicitly on drawings and approved by the Architect.
2.2.2 All pipeworks shall be installed by competent persons in a sound and workmanlike manner throughout, with full provision for venting, draining down, expansion and contraction, cleaning, maintenance and renewal or replacement. Whenever possible pipes shall be laid in protected positions. No pipes shall be laid so as to cause obstruction in ducts, passages, doorways, windows etc. Exposed pipework shall not be permitted in occupied areas without the prior approval of the Architect.
2.2.3 Special care shall be taken to prevent dirt or extraneous materials entering the open ends of all pipework during erection. During the course of installation, all open ends shall be plugged or capped with metal cap or plugs only. The use of shavings, rages, etc. will not be allowed.
When any section of the pipework is left incomplete for any purpose, the pipe shall be securely sealed with purposely made plastic blanking caps.
2.2.4 All pipework shall be cut square, free from burrs and to maintain the full bore. Pipework shall be thoroughly cleaned before erection.
2.2.5 Where pipes pass through wall and floors, sleeves shall be fitted to allow free axial movement of the pipes. Sleeves shall be of a material compatible with the pipe it protects and of a minimum bore to allow such movement and of length to protrude 3 mm above and below the floor, or on either sides of wall. The annular space between pipe and sleeve shall be packed with a suitable fire resisting material to prevent the passage of fire by the Contractor.
2.2.6 All pipes shall be properly and substantially supported by approved hangers, brackets, clips or supports designed to suit the requirements at each support point and so placed or protected as to ensure that there is no damage to the pipes. Piping shall be neatly grouped and arranged with the minimum number of cross-overs. Pipelines exposed to physical damage shall be provided with suitable protection. All exposed pipework shall be installed in the neatest possible manner to the satisfaction of the Architect.
2.2.7 Where pipes are laid to points for future use only, the ends shall be securely capped or plugged.
2.2.8 Valves shall be properly fixed in a conspicuous and readily accessible positions.
2.2.9 Town gas pipes shall not be used as earthing conductor. Their bondings to the electrical earthing conductors shall be carried out by the Contractor in accordance with the requirements as stipulated by the I.E.E. Wiring Regulations and the Electrical General Specification, and to the approval from the Architect and the corresponding electricity supply companies.
2.2.10 All pipes shall be free from flattening, buckling or evidence of wall thinning.
2.2.11 All pipework, fittings, valves, connections etc. shall be properly supported and bracketed.
2.2.12 All pipework shall be tested after erection, if necessary in section to avoid holding up other trades. No pipework shall be cased in before it has been tested and satisfactorily passed the specified tests.
2.2.13 All brackets and supports shall be hot dip galvanised steel.
TC R318 - PS-40/2 -