PTA CNG Bus System Upgrade

1.1 Background
1.1.1 The objective of this CNG bus upgrade is to supply, install and test a Safety Valve Assembly (SVA) on PTA’s fleet of 473 Mercedes Benz OC500 CNG buses to restrict the flow of gas from the Compressed Natural Gas (CNG) storage cylinders in the event of a high pressure gas line failure downstream of the SVA. The SVA will be located under the CNG fuel pod cover in close vicinity to the CNG cylinder(s) quarter turn isolation valve.
1.2 Scope of Services
1.2.1 The Contractor must prepare written SVA assembly and vehicle fitment procedures. These procedures must be approved by the PTA and adhered to at all times.
1.2.2 The SVA must be assembled in a clean environment with the aid of appropriate jigs and fixtures and under the supervision of a person holding an E class unrestricted CNG permit that is recognised in the state of Western Australia.
1.2.3 Each SVA is to be serialised for traceability purposes.
1.2.4 Each SVA must be leak checked to a min of 150 bar prior to fitment to vehicle.
1.2.5 The excess flow valve must be checked that it is operating properly prior to the SVA being fitted to the vehicle.
1.2.6 The assembly and testing of each SVA must be recorded. These records must be maintained by the Contractor for a period of 5 years and made available on request.
1.2.7 The fitment of the SVA to the bus will be carried out by personnel holding an E class unrestricted CNG permit that is recognised in Western Australia. The use of trades assistants to help with the fitment of the SVA to vehicle is permitted providing that the licensed person holding the E class unrestricted CNG permit is in attendance at all times.