Instrument Design Checking Procedures

This article is about Instrument Design Checking Procedures and checking of Instrument Location Drawings, Control Panels, Instrument Hook-Up Details, Analyzer Panels, Field Instrument Support Details, Instrumentation Bill of Material, Instrumentation Index.

1.  PURPOSE

This engineering standard provides a consistent checklist for all instrumentation design packages, based on department standards, supplier, and construction feedback.

2.  SCOPE

2.1      This standard applies to all Sale of Gas (SOG) and Sale of Equipment (SOE) facilities.

3.  Related Engineering Articles

Instrument Location Drawings

Instrumentation Tubing Hookup Details

Instrument and Electrical Control Panels and Equipment

Instrument Analyzer Panels for Dry-Indoor Environment

Field Instrument Support Details

Item Selection on the Instrumentation Bill of Material

Tubing for Instrumentation Service

Copper Tubing, Brass Fittings, and Valves for Instrument Service

Stainless Steel Tubing, Fittings, and Valves for Instrument Service 170 bar g (2500 psig) Maximum

Stainless Steel Tubing, Fittings, and Valves for Instrument Service 415 bar g (6000 psig) Maximum

Bundled Tubing for Instrument Service

Electrically Traced Tubing for Instrument Service

Analyzer Calibration Gases and Manifold Regulator Assembly

Analyzer Vent Systems

Project specific  Instrument Index

4.  CHECKING PROCEDURE CRITERIA

1. The Instrument Design package checking procedures are based on design standard guidelines, field construction feedback, and panel supplier or fabricator feedback, Air Products Global Operations feedback, and customer feedback.
2. The checking procedure is generated to maintain a high level of quality within Instrumentation Design by ensuring standardization, meeting all customer expectations, including all safety criteria, and performing all work in the most cost-effective way.
3. To perform a high quality level of checking of an instrumentation package, an instrument designer shall refer to the appropriate reference documents listed in the Related Documents section of this standard.

5.  CHECKING OF INSTRUMENT LOCATION DRAWINGS

1. Field installed instruments are identified and located per the flowsheet with associated instrument index, hookup and support detail included.
2. Instrument process tap connections are located with elevation, associated instrument, and hookup identified.
3. Control valves are identified per the flowsheet with elevation and associated hookup included.
4. Analyzer tubing connections are located per the flowsheet with tap elevation, associated analyzer connection, and hookup included.
5. Main instrument air header is identified with block valves and hookup number.
6. Instrument tubing junction boxes and bulkhead bars are located with associated fabrication details included.
7. Analyzer panels and calibration gas cylinders are identified and wall penetrations are located.
8. Calibration gases are correctly identified per the analyzer specifications, and dimensional details for the fabrication of gas cylinder racks is provided.
9. Instrument air users are identified.
10. Field-mounted instruments are located in an accessible location.
11. All instruments that are electrical traced and steam traced are properly located according to their process conditions.

6.  CHECKING OF CONTROL PANELS

1. All front and rear of panel instruments are identified per the flowsheet including dimensional information. All instruments are labeled correctly per the bill of materials.
2. Panel is properly designed for indoor or outdoor applications.
3. Panel is properly identified with removable base for overseas shipping, if required.
4. Panel color is Air Products standard unless otherwise specified by the customer.
5. Any customer-requested items or layout procedures are followed.
6. Panel is designed for the proper electrical area classification.
7. Appropriate local code requirements are specified. Some examples are:  CSA, UL, FM, or CENELIC.
8. Dimensional information is presented in either imperial or metric.
9. Panel layout is approved, if required (by Process Controls, Global Operations, or customer).
10. Panel design has adequate ventilation, heating, and cooling for the heat loads generated inside the panel, as well as outdoor ambient and sun heat loading.
11. All front and rear of panel lights, switches, pushbuttons, relays and timers are mounted and identified per wiring schematics and bill of material.
12. Power distribution is correct per electrical schematics.
13. Fuses are installed properly for 24 Vdc power distribution.
14. 20% spare terminal blocks are provided for all ac, dc, RTD, and thermocouple (TC) wiring.
15. Additional terminal strips are provided for jumpering of electrical field wiring, if required.
16. Ac and dc devices and wiring are properly segregated in panel.
17. Wiring schematic and loop diagrams are properly referenced.
18. All the specifications and standards for the panel are listed on the drawings.

7.  CHECKING OF INSTRUMENT HOOK-UP DETAILS

1. All field located instruments are detailed per flowsheet.
2. All required tubing and fittings are identified with correct bill of material item numbers.
3. All oxygen service or ultra-high purity (UHP) service tubing is properly identified for hydrocarbon decontamination.
4. Electric heat-traced tubing is identified per flowsheet.
5. Steam-traced tubing is identified per flowsheet.
6. 2-way manifold valves are installed properly in process tubing service for instruments.
7. “Lock-Open” or “Lock-Closed” block valves with orange handles and Valve Lockout accessory are installed per flowsheet.
8. All instruments installed in steam service piping are properly installed.
9. All instruments installed in wet gas or vapor service are properly drained and/or heat traced. Example:  MAC flowmeter instruments.
10. Any analyzer requiring instrument air is properly detailed.
11. Condensate chambers are installed in any process tubing containing water and proper slope of tubing is detailed.
12. Flow restrictors are installed in all combustible gas samples.
13. Analyzer vent header system is correctly detailed showing outside venting above building roof line and header condensate drain tubing installed inside building and vented outside.
14. Instrument air supply sub-header is detailed with piping properly sized per the number of users.
    • 15 mm (1/2 in) pipe for 0–10 users.
    • 20 mm (3/4 in) pipe for 11–20 users.
15. Instrument air supply sub-header for switch valves is reviewed with specifying engineer.
16. Instrument air users are detailed per the flowsheet and instrument specifications.
17. Analyzer sample and calibration gas tubing connections are properly detailed.
18. Stainless steel and copper tubing are properly used.
19. The use of threaded connections is minimized in combustible gas tubing.

8.  CHECKING OF ANALYZER PANELS

1. Analyzer panels are properly sized for specified analyzers and associated equipment.
2. Sample tubing, fittings, and miscellaneous items are identified for “hydrocarbon decontamination” when required.
3. Sample and calibration gas connections are correct per analyzer specification and flowsheet.
4. Sample system is designed in accordance with the proper sample system standard.
5. Analyzer wiring for alarms, switches, and signals is correctly detailed per the flowsheet, analyzer specification, and electrical wiring schematics.
6. Analyzer cabinet layout is approved by Process Controls, Global Operations, or customer.
7. Proper calibration gas MIX IDN and regulator manifolds are specified for order by project engineering.
8. All the specifications and standards for the panel are listed on the drawings.
9. Issue project engineering order list for any KIP valves and manifolds required for the sampling system.
10. Panel color is Air Products standard unless otherwise specified by the customer.
11. Any customer-requested items or layout procedures are followed.
12. Appropriate local code requirements are specified. Some examples are:  CSA, UL, FM, or CENELIC.
13. Dimensional information is presented in either imperial or metric.
14. Ac and dc devices and wiring are properly segregated in panel.
15. 20% spare terminal blocks are provided for all DC wiring.

9.  CHECKING OF FIELD INSTRUMENT SUPPORT DETAILS

1. Supports are specified as galvanized or painted depending on project scope or customer’s request.
2. The correct support is identified on the instrument location drawings per the type of instrument specified.

CHECKING OF INSTRUMENTATION BILL OF MATERIAL

Item numbers are correct per the hookup details and support details.

CHECKING OF INSTRUMENTATION INDEX

Items are correct per the P&ID, instrument specifications, location drawings, hookup details and support details.