P&ID extraction for lng.
LNG facilities are SIS-dense by design. The cryogenic process is unforgiving, 2oo3 voting on critical services is routine, and proof-test cadence sits on a 6-12 month clock the audit register has to track.
What lng drawings carry.
- Liquefaction trains carry redundant temperature, pressure, and level transmitters voting 2oo3. Redundancy annotations preserved
- Storage tank overfill protection, LSHH multi-layer, vented spill containment carries the facility's highest-SIL services
- Custody-transfer metering, Coriolis or USM carries weights-and-measures audit scope alongside controls scope. Both surface in the extraction
- Cryogenic service drives strict material specification. Line list preserves spec-break notation through the cold box
- Boil-off gas, BOG handling and reliquefaction loops add a dense instrumentation block tied to storage tank pressure control
- Marine loading arms, ship-shore communication, and ESD interfaces filter into a terminal-scope subset distinct from upstream process
- Liquefaction lineage, APCI, Cascade, Linde MFC, ConocoPhillips Optimized does not change I/O list output but affects parent equipment list and cold-box nomenclature
- Cryogenic relief and venting are heavily instrumented. PSV inlet and outlet temperature monitoring appears across multiple drawings
What the extraction delivers.
- Per-unit I/O list, gas treatment, liquefaction trains, storage and loading
- Comprehensive SIS instrument index with SIL allocation references
- Cryogenic line list with metallurgy and insulation flags
- Custody-transfer metering scope filtered into a separate audit register
Instrument tags on a lng drawing.
- TT-LN-1015-1oo2Liquefaction train 1 cold-box temperature, voted 1oo2
- LSHH-ST-302Storage tank 3 overfill switch, SIS-classified, segregated cabinet
- FT-CT-401Custody-transfer flow on the export berth manifold
- MT-DH-205TEG dehydration outlet moisture analyzer
- PT-BOG-601-2oo3Boil-off gas header pressure, voted 2oo3
- ESDV-MLA-2-04Marine loading arm 2 emergency shutdown valve, position 04
Regulatory context.
- IEC 61511, ISA 84. SIL allocation and proof-test discipline at the highest end of the spectrum
- API 625 for storage tank design
- USCG, US and equivalent maritime authorities for export terminal scope
- Custody-transfer metering audited under NIST Handbook 44 or international equivalents
Which discipline reads it.
Controls EngineersCryogenic instrumentation across liquefaction trains. Tank-farm and jetty signal scope.Process EngineersCascade or mixed-refrigerant cycle balance. Cold-box stream summary integration with the recovery loop.Functional Safety EngineersSIS scope on tank overfill, BOG compressor trip, and ESD network. LOPA per API 521 and NFPA 59A.Piping and Mechanical EngineersCryogenic line classes, 9% nickel, austenitic stainless. Vacuum-insulated piping notation preserved.
Common questions
Does Tagsight handle the SIL 3 service density typical of LNG plants.
The extraction captures the tag, the SIS prefix, and the voting annotation. SIL allocation values come from the SRS and join on tag during downstream analysis. Tagsight does not assign SIL. It surfaces the data the SIL audit needs.
How is custody-transfer scope handled.
Filter the extracted set on the CT prefix or tagging convention in use, export the subset, and feed it into weights-and-measures documentation separately from BPCS, SIS exports.
Can it handle marine loading and terminal scope alongside the liquefaction train.
Yes. Marine loading arms, jetty ESD systems, and ship-shore link instrumentation extract as a separate workspace from the liquefaction trains, keeping maritime-regulatory documents filterable from the IEC 61511 audit set.
How is small-scale LNG handled vs baseload.
Same pipeline. Small-scale and peak-shaver plants carry lower instrument density per drawing but the SIS architecture and proof-test cadence are not relaxed. The output documents are identical. Scope size differs.
Does the line list capture cold-box metallurgy correctly.
Spec break notation is preserved as drawn. Cryogenic lines, 9% nickel, austenitic stainless, brazed-aluminum exchanger internals are captured with the spec code the drawing uses. Plain-text material notes are captured in the description field.
Run it on your lng drawings.
Upload a P&ID set and see the instruments, equipment, and lines it reads before committing to a plan.