What This Type of Data Looks Like
Business documents for refinery and chemical production fall into four categories: process specifications, equipment ledgers, production reports, and safety compliance documents. Sources include on-site operation and maintenance records, data exported from central control systems, and compliance manuals issued by superior units. Update frequency varies by document type: process specifications are revised every quarter, equipment ledgers are updated alongside maintenance cycles, and production reports are generated daily. Most documents consist of long text passages, mixed with embedded tables and process flow annotations. Standardized fields include equipment identification numbers, pressure values (unit: MPa), and temperature values (unit: ℃).
Constraints Imposed on the Document Parsing and Chunking Stage
Long, frequent text passages and continuous process operation steps can split complete operational logic if fixed character-length chunking is used. This will prevent full guidance from being retrieved during searches. Embedded tables are tied to parameter units. Standard text chunking will break the link between units and fields, reducing retrieval accuracy. Individual documents can be large; some large equipment ledgers reach hundreds of pages, which may trigger timeouts or file size limits during parsing. Mixed-format documents require simultaneous handling of text, tables, and annotations. General chunking rules cannot meet the extraction needs of this structured content.
Configuration Settings
| Configuration Item | Recommended Setting | Rationale |
|---|---|---|
chunkSize | 800–1200 characters | Aligns with the length of process passages in long refinery documents, avoiding splitting critical operation steps |
chunkSplitter | Paragraph + title | Preserves the hierarchical structure of process specifications, preventing breaks in continuous operational workflows |
customPdfParse | Enabled | Adapts to embedded tables and process flow annotations in refinery documents, extracting structured content |
UPLOAD_FILE_MAX_SIZE | 500 MB | Meets the size requirements for individual large equipment ledgers or annual production reports |
PARSE_FILE_TIMEOUT_SECONDS | 600 seconds | Addresses parsing time for long documents, preventing mid-task interruptions |
chunkSettingMode | Manual configuration | Adjusts chunking rules for the special structure of refinery documents, adapting to mixed long text and table content |
Three Common Misconfigurations
- A 504 status code request error occurs when uploading a PDF. This happens because the
PARSE_FILE_TIMEOUT_SECONDSparameter is not adjusted, and long document parsing exceeds the default threshold. - Field disorder and missing units appear in parsed content after importing Feishu multi-dimensional tables or Excel material balance sheets. This happens because
customPdfParseis not enabled, and structured extraction rules are not configured for table documents. Direct plain-text chunking breaks table structure. - No response when clicking the original document in search results. This happens because metadata identifiers for the original document are not extracted during parsing, and no association is established between the index and the original file.
How to Verify Correct Configuration
- Upload a single large refinery equipment ledger PDF under 500 MB, and check if parsing completes within 10 minutes.
- Import an Excel document containing process parameter tables, and check if parsed table fields and units are fully retained without disorder.
- Search for process keywords in long documents, and check if search results include complete operational passages without incorrect splitting.
- Check the FastGPT v4.17.0 parsing log to confirm no timeout or file size limit error messages appear.
The values provided here are common starting points, and should be evaluated against the reader's own samples.
Question material comes from public community discussions. Configuration values are common starting points and should be measured against your own samples. Verified on 2026-09-28.