Can someone clarify on the following regarding Hazardous area classification for underground valves which are buried :


1) If there is a buried valve on a piping with natural gas, do we need to classify a hazardous area around the valve (as in case of an above ground valve)? I understand that buried valves do not require classification as per IP 15 or other codes.

2) Underground pits in a classified area is normally zone-1 when the pit does not have a source of release by itself as per IP 15.
However, if the pit has a natural gas isolation valve, it is still zone-1?

The piping pressure is about 30 barg.

thank you.

Vijay