بخش ۱۷-۱۶-quality-control-testing-inspection-issuing-approval-delivery-and-injection-of-gas-in-the-gas-piping-system-the-second-part-of-natural-gas-piping-with-a-pressure-of-۲-to-۶۰-pounds-per-square-inch | مبحث هفدهم: لوله کشی گاز طبیعی

بخش ۱۷-۱۶-quality-control-testing-inspection-issuing-approval-delivery-and-injection-of-gas-in-the-gas-piping-system-the-second-part-of-natural-gas-piping-with-a-pressure-of-۲-to-۶۰-pounds-per-square-inch | مبحث هفدهم: لوله کشی گاز طبیعی