API RP 551: Process Measurement Control Systems for Petroleum, Petrochemical, and Natural Gas Industries
The American Petroleum Institute (API) has published a recommended practice (RP) for process measurement instrumentation, known as API RP 551. This document provides guidelines for the selection, installation, operation, and maintenance of process measurement instruments used in the petroleum and natural gas industries. In this post, we'll take a closer look at API RP 551 PDF and its significance in the industry.
- Flowchart of the 3-stage ECDA process.
- Sample risk-ranking table (columns: location ID, threat factors, score, priority).
- Inspection field sheet (fillable fields).
- Excavation safety checklist.
- Sample report table of contents.
- For a new tapping point: Start with Chapter 5 (Pressure) → Table 1 (impulse line slopes).
- For a troubleshooting plugged impulse line: See Section 5.4 (seal systems) and 5.6 (purges/block valves).
- For a high-temperature thermowell: Skip to Chapter 6 → Table 3 (recommended materials for 600°F+).
- For level on a fouling service: Review Chapter 7 → guidance on external chambers vs. direct flange-mount.
API RP 551 is a recommended practice that provides guidelines for the selection, design, installation, and maintenance of process measurement and control systems in the oil and gas industry. The document covers various aspects of process measurement and control, including:
Q2: Does the PDF include calculation software or spreadsheets?
- Sizing impulse piping for viscous or fouling services.
- Best practices for isolating diaphragms and chemical seals.
- Installation of pressure switches for high-integrity protection systems (HIPPS).
Impulse Piping:
Ensuring lines are sloped correctly to prevent gas pockets or liquid traps.
