These recommendations cover the conceptual design, operation and safety aspects of venting of Natural Gas for the depressurisation of plant or equipment for onshore vertical vent systems.
They are not intended to cover the detailed design, manufacture, installation, maintenance and inspection of the hardware, or to cover flare systems, though they do provide guidance in the event of vented gas being ignited. They only cover releases of liquid free Natural Gas which have a combined proportion of methane plus inerts of greater than 89% by volume and temperature between -50°C and 50°C from vent stacks with internal diameters equal or greater than 25 mm of flow rates up to 40 kg s-1.
They do not apply to instrumentation vents and purging and venting operations where small volumes of gas are released.
The scope of the standard includes:
- Relevant Legislation
- Vent design, including stack exit velocity, flow control, gas dispersion, thermal radiation and ignition sources
- Design of permanent vent systems, including pipework and vent stack location
- Additional concerns for consideration with temporary vent systems
- Major planned venting operations.