AS 4645-2005 pdf free download

AS 4645-2005 pdf free download.Gas distribution network management.
4.4.3 Associated pipework
4.4.3.1 Pipe for re,noval of liquids
Where water. hydrocarbon liquids, condensates or other liquids may accumulate in a main or service, there should be adequate provision for collecting and removing the liquids. This may include appropriate grading of mains and services, and the provision of liquid removal points. Each removal point shall he in an accessible location, and that location clearly indicated.
4.4.3.2 Isolailon valve requiren,e?iIs
Isolation valves shall be provided as specified in Clause 4.4.1.2. and shall comply with the following:
(a) An isolation valve, and associated fittings and accessories shall be lit for purpose, and the design shall ensure compliance with relevant Standards nominated by the network operator. The specific requirements of AS 1697 and AS 3723 shall apply as appropriate to the pipe system material.
(b) Where an isolation valve is installed in a buried box or an enclosure. ready access to the operating stem or mechanism is required. The box or enclosure shall not transmit external loads to the mains, or chafe the pipe. The valve box cover of a buried box shall he flush with the finished ground surface.
(c) An isolation valve installed below ground shall be of a design approved in writing and tested at the maximum test pressure for that location.
(d) A buried isolation valve shall he located in a valve box that is approved in writing and having a hinged or removable lid that is identified in its upper surface by either
or ‘Gas’, or by the network operator identification.
(c) Where a turnkey is required. the turnkey shall he located in a readily accessible location determined by the network operator to make it available for use in an emergency.
4.4.4 Corrosion mitigation of buried steel pipe
Measures shall be taken to mitigate corrosion of steel mains and services, so as to maintain asset integrity, safely and reliability. When deterniining necessary measures, consideration shall he given to the potential for both internal and external corrosion and degradation. Implicit with and central to a corrosion mitigation strategy is the design of corrosion and condition monitoring programs to provide assurance that the measures implemented are successfully achieving their objectives.AS 4645-2005 pdf free download.