A Lesson Learned Initial Service Testing for 2 Phase Line and Steam Line of 110 MW Wayang Windu Unit 2 Field

Abstract

In Geothermal steamfield above ground systems, 2 phase pipe line usually used very large diameter (greater than 1 meter) covering long distances and varying elevations over cross country. Hydrostatic testing of these systems is becoming problematic and usually not so practical, this is because the piping is typically not designed for full water load, the large volumes of water required, and often the changes in elevation make it impossible to test the whole system at once. Initial service test is therefore preferred internationally as it often significant advantages over hydrostatic testing and is proposed for testing of the Wayang Windu unit 2 Steam field Above Ground System large diameter (36", 42" and 48") two phase and steam piping. So this is a lesson learned from Wayang Windu unit 2 whereas the initial service test has been done and performed at "normal operating pressured". For the first time, this testing has been approved and the field had received the SKPP and SKPI form EBTKE (former DJMBP). This techniques has reduced the EPC completion time and reduce the cost in term of civil work. In-service test is actually quite simple and the procedure followed ASME B31.1 Power Piping. in principle, the line is headed to 100 deg C with all vents and drains are opened ie under no pressure and then after temperature raised and the pressure raised to the service test pressure. This test to be a more stringent test as the thermal loading is likely exceed loading under a hydro-test at ambient temperature. Service leak test are common practice for Geothermal Project worldwide, Mighty Power River from New Zealand and also in Kenya and Philippines and Nicaragua they have been using service leak tests on their new geothermal pipelines as their standard for some time. This best practice could be proposed to EBTKE, as regulator, to adopt it into their regulation regarding safety audit to installation, equipment and technique use in geothermal activities.