LNG power plants, tanks, offshore and onshore terminals and compression stations require strong motion instrumentations. Typical normative requirements are according to Safety Integrity Level 2 or 3 (SIL 2 or SIL 3) according to IEC 61508.
Syscom solution fully complies with these requirements with the MRSK2002 accelerographs. The SIL 2/3 in double or triple redundancies are suitable to automatically TRIP safety valves or other critical systems related to the site safety.
The equipments are usually protected by ATEX qualified enclosures, like Ex d housings, for explosion protection.
The main requirements of a safe monitoring system are:
A complete seismic instrumentation system monitors the impact of an earthquake at critical locations and at a free field location unaffected by the buildings. The instruments should be environmentally qualified and in compliance with the international safety standards, such as IEC 61508.
The data coming from each accelerograph is collected in a control room, where the operators can see if some unexpected vibration has been recorded and take actions when required.
The analysis of the data recorded is made by seismologists and structural engineers, especially when the structural response exceeds specified limits. Operating Basis Earthquake (OBE) and Safe Shutdown Earthquake (SSE) levels are widely referred to in that case.
The vibration monitoring is also useful to guarantee an automatic shutdown of the site critical systems and drastically mitigate the critical failure risks in case of an earthquake.