- PURPOSE
1.1 This specification defines for the contractor the minimum requirements for field installed instrumentation.
- SCOPE
2.1 This engineering specification applies to domestic instrument installations.
- RELATED DOCUMENTS
3.1 Air Products Engineering Documents
3PI55005 Pipe Thread Sealants Service Index
4ACS-640131 Fabrication of Miscellaneous Metals
4API-630292 Instrument Air Supply Piping Specification
4PS52001A Copper Tubing, Brass Fittings, and Valves for Instrument Service
4PS52002A Stainless Steel Tubing, Fittings, and Valves for Instrument Service 170 bar g (2500 psig) Maximum
4PS52003A Stainless Steel Tubing, Fittings, and Valves for Instrument Service 415 bar g (6000 psig) Maximum
4PS52004A Bundled Tubing for Instrument Service
4PS52005A Electrically Traced Tubing for Instrument Service
4PS52006A Steam-traced Tubing for Instrument Service
4WCE-670200 Fabrication and Erection of Process Piping
4WEQ-6804 Painting and Corrosion Protection of New Construction for Design Temperature to 649°C (1200°F)
4WPI-SW70001 Standard Clean (Class SC) Inspection and Acceptance Requirements
4WPI-SW70002 Process Clean (Class B) Inspection and Acceptance Requirements
4WPI-SW70003 Oxygen Clean (Class AA) Inspection and Acceptance Requirements
4WPI-SW70004 Fluorine Clean (Class AAAA) Cleaning, Inspection and Acceptance Requirements
3.2 American Society for Testing and Materials (ASTM)
F593 Specification for Stainless Steel Bolts, Hex Cap Screws, and Studs
F594 Specification for Stainless Steel Nuts
- GENERAL
4.1 Air Products will furnish all tagged instruments and control devices as listed in the Instrument Summary. The contractor’s responsibility for each item is defined on the contract installation drawings.
4.2 The contractor shall furnish all materials described on the contract drawings unless specifically indicated otherwise. The contractor shall furnish all miscellaneous and incidental materials necessary for a complete and operable system.
4.3 The contractor shall install all instruments, control devices, and related materials in accordance with the contract drawings and other construction specifications.
4.4 Unless otherwise indicated, the mechanical contractor shall install all in-line devices, control panels, and process taps up to and including the primary shutoff valve. In-line devices include all items necessary to complete the process piping system for pressure testing.
4.5 The contractor shall receive, store, and account for all instruments and materials that are to be installed under this contract. Special care shall be taken to ensure that items which are furnished “Cleaned for Oxygen Service” do not become contaminated. The furnished protective packaging shall remain on the process connections of such items until the final connection of the process leads is made.
4.6 Penetration of the cold box is not permitted. All tube/instrument supports secured to the cold box will be attached by welding only. Do not weld supports to cold box panels designated as removable or route tubing to interfere with removal.
- INSTRUMENT LOCATIONS
5.1 The placement of instruments on the contract drawings are approximate, and the contractor shall not mount instruments in a manner that obstructs the operation or maintenance of equipment. The instruments shall be accessible and removable for maintenance.
5.2 The installation of instruments shall not obstruct the following:
Walkways
Platforms
Ladders
Stairs
The operation, maintenance or removal of equipment, control panels, or overhead cranes.
5.2.1 All tubing installed over walk/access ways shall be a minimum of 2285 mm (7 ft 6 in) above grade or platform elevation.
5.3 All instruments and control devices installed by the contractor shall be adequately supported even if a specific support detail is not shown on the contract drawings. Items such as regulators and pneumatic relays may not be supported solely by the tubing. They shall be independently supported.
- TUBING, FITTINGS and VALVES
6.1 All process or pneumatic tubing will be 10 mm (3/8 in) outside diameter (OD) copper or stainless steel unless otherwise specified on contract drawings. Analyzer sample tubing will be 6 mm (1/4 in) OD copper or stainless steel unless otherwise specified on contract drawings.
6.2 Copper
6.2.1 Copper tubing, fittings, and valves shall be as required by 4PS52001A.
6.3 Stainless Steel
6.3.1 Stainless Steel tubing, fittings, and valves shall be required by 4PS52002A.
6.4 Stainless Steel-High Pressure
6.4.1 High pressure Stainless Steel tubing, fittings, and valves shall be required by 4PS52003A.
- TUBE ROUTING AND INSTALLATION
7.1 The contractor shall route tubing and locate supports in a manner that avoids obstructing operation, maintenance or removal of equipment, instruments, control panels, and overhead cranes. Walkways, platforms, ladders, and stairs shall not be obstructed in any manner. The contractor shall obtain approval from the Air Products representative before routing any instrument tubing. If dimensional locations or slope details are provided, however, they must be applied without modification while maintaining the guidelines set forth in paragraph 5.2.
7.2 Unless specifically indicated otherwise, the contractor shall furnish, fabricate, and install tubing and tubing support systems in accordance with the contract drawings and the construction specifications.
7.3 All tubing runs shall be installed and supported in accordance with Section 10 of this specification. The finished installation shall display a high quality of workmanship and shall be subject to a pre-acceptance final inspection by the Air Products representative. The requirements (in addition to those specified in the contract drawings and standards) are as follows:
7.3.1 Tubing runs shall be installed straight and parallel or perpendicular to equipment lines and shall be uniformly spaced. Rolled tubing must be stretched straight before installation. Tubing shall be stretched no more than 1% [150 mm (6 in) per 15.2 m (50 ft) coil].
7.3.2 Tube bends shall be made with industrial type tube benders and a minimum radius of four times the tube diameter. Bent tubing shall not display obvious flattening or distortion.
7.3.3 Unsupported runs of 6 mm (1/4 in) OD copper tubing shall not exceed 300 mm (12 in). Unsupported runs of 10 mm (3/8 in) OD or larger copper and stainless steel tubing shall not exceed 600 mm (24 in).
7.3.4 To minimize the quantity of tubing unions required, the maximum practical continuous lengths of tubing shall be used on all process and analyzer sample tubing.
7.3.5 All instrument tubing and supports shall be a minimum of 200 mm (8 in) from any cryogenic or process piping that has yet to be insulated.
7.4 Swagelok or Parker A-Lok tube fittings shall be installed in strict accordance with the manufacturer’s instructions. The contractor shall have at least one copy of Swagelok’s or Parker’s Tube Fitting and Installation Manual on-site and shall ensure that personnel installing tubing are familiar with the manual contents. Classes conducted by the selected manufacturer are the preferred procedure to ensure a quality installation. Conformance to the “1-1/4 turn” tightening procedure is of particular importance.
7.5 The contractor shall ensure that all personnel who install tubing are furnished with Swagelok’s or Parker’s “No-Go” inspection gauges and that each and every fitting is checked with a gauge by the installer upon completion.
7.6 All tubing shall be “bottomed out” into the fitting before ferrules are made up and the fitting is tightened.
7.7 The contractor shall refer to 3PI55005 for thread sealants used on all pipe connectors and shall not apply the selected material to the leading two threads of the fitting.
7.8 The contractor shall not cut or crimp capillary tubing. The tubing shall be supported and protected in channel with all excess tubing coiled at the related instrument.
7.9 The National Electrical Code (NEC) prohibits the installation of tubing and/or tube bundles by any means on, from, or in cable tray systems that contain electrical cables.
7.10 Unless otherwise specified on contract drawings, the contractor’s tubing installation responsibility stops at all panel bulkheads.
7.11 When tubing tees are used for bleeding or calibration, the compression fitting nut must be removed before installing the plug.
- TUBE BUNDLES
8.1 Tube bundle information will be detailed on the contract drawings and shall be as required by 4PS52004A.
8.2 Tube bundles may be used in lieu of single runs if the instrumentation contractor believes there will be a cost savings in material and installation. The contractor must consult, with the Air Products field representative and Instrument Design before deviating from the contract drawings.
8.3 Refer to 4PS52004A when the contract drawings detail the tube bundles as direct buried.
8.4 Tube bundles shall be supported in accordance with Section 10 of this specification.
8.5 Junction boxes and bulkhead bars shall be used per the contract drawings.
8.6 Tube bundles which originate in junction boxes in hazardous locations shall be sealed if the bundle leaves the hazardous area. Sealing will be accomplished by extending the sheath 50 mm (2 in) inside the box separating the tubes at the end of the sheath, and sealing with room temperature vulcanizing (RTV) compound. The RTV seal shall be 100 mm (4 in) long and shall lap the sheath by 25 mm (1 in). The box shall be vented with a breather/drain fitting in the bottom of the enclosure.
8.7 When provided, spare tubes shall be terminated on bulkhead fittings with the inner bulkhead fitting capped.
- ELECTRICALLY AND STEAM TRACED TUBING
9.1 The contractor shall install all electrically traced tubing per the contract drawings. All electrical connections to the tracing shall be performed by the electrical contractor.
9.2 The contractor shall install all steam traced tubing per the contract drawings and as required by 4PS52005A for electrically traced tubing and 4PS52006A for steam traced tubing. The primary steam header, shut-off valve, and steam trap shall be installed by the general contractor unless otherwise specified on the contract drawings.
9.3 The contractor shall mark each instrument housing and traced system at 9144 mm (30 ft) intervals, “electric traced” or “steam traced.”
- TUBING SUPPORTS AND MATERIAL
10.1 Materials
10.1.1 All tubing support systems shall be constructed of the same material used for the electrical cable support system (aluminum).
10.1.2 All support members and fittings shall be a minimum of 2.7 mm (12 gauge).
10.1.3 Hardware shall be 300 Series stainless steel in accordance with ASTM F593 and F594.
10.2 Support Systems
10.2.1 Support systems will be used for either vertical or horizontal runs. The selection of an individual system will depend on the quantity of tubes or bundles to be carried.
10.2.2 Angle supports may be used to support a single bundle or up to four individual tubes. Angle supports shall meet the following specifications:
10.2.2.1 Size: 50 x 50 mm (2 x 2 in).
10.2.2.2 Fittings: 76 mm (3 in) radius; 300 mm (12 in) radius for bundle supports.
10.2.2.3 Spans: 900 mm (3 ft) normal; 1800 mm (6 ft) maximum.
10.2.2.4 Tie-downs: Clamps at 600 mm (2 ft) intervals.
10.2.3 Tube channel shall be used for runs along flat, continuous surfaces or short branch runs from a main tray. Tube channel may carry one or two bundles or up to eight individual tubes. Tube channel shall meet the following specifications.
10.2.3.1 Width: 50 mm (2 in) minimum; 100 mm (4 in) maximum.
10.2.3.2 Sizing: Minimum inside width shall be 1.25 times the total width of installed tubes and bundles.
10.2.3.3 Fittings: 300 mm (12 in) radius.
10.2.3.4 Spans: 1200 mm (4 ft) normal; 2400 mm (8 ft) maximum.
10.2.3.5 Tie-downs: Bundle or tube clamps at 900 mm (3 ft) intervals.
10.2.4 Ladder tray shall be used where the conditions for the tube channels are not met or if there are more than eight individual tubes. Ladder tray shall meet the following specifications:
10.2.4.1 Side Rails: 100 mm (4 in) nominal height with outside flanges.
10.2.4.2 Rungs: 230 mm (9 in) center-to-center spacing.
10.2.4.3 Length: Expansion joints required for straight runs in excess of 18,000 mm (60 ft).
10.2.4.4 Connections: Splice plates, minimum four bolts each per side connection.
10.2.4.5 Width: 150 mm (6 in) minimum; 600 mm (24 in) maximum.
10.2.4.6 Sizing: Minimum inside width shall be 1.25 times the total width of installed tubes and bundles.
10.2.4.7 Fittings: 300 mm (12 in) radius.
10.2.4.8 Spans: 3600 mm (12 ft) normal; 6 m (20 ft) maximum.
10.2.4.9 Tie-down: Bundle clamps and tube straps shall be installed at 2100 mm (7 ft) intervals [900 mm (3 ft) for vertical runs].
10.3 Installation
10.3.1 The support system shall be installed using galvanized hangers, clamps, brackets, or other attachment devices manufactured by or recommended by the manufacturer of the support system. Supports for tray, channel, and angle systems shall be provided at all fittings and at the normal span intervals specified in paragraph 10.2. Supports shall be spaced at the maximum spans only when closer support is not possible. Fittings or splices shall not be permitted in any span that exceeds the normal span interval. Supports shall be attached to structural steel, building structural members, or along the structural members of cold boxes.
10.3.2 Tubing and tube bundles shall be installed in and secured to the support system at the intervals specified in paragraph 10.2. All fittings shall be elevated from the plane of the run and staggered to permit accessibility. All tubing runs shall consist of a single layer, except in congested areas where tubing may be stacked for short distances where the run is installed without fittings.
10.3.3 The bundle and tube clamps and tube straps required for paragraph 10.2 shall be of metallic construction designed for bolted installation. Less secure devices, such as push-clips, tie wraps, and plastic retainers, shall not be used.
10.3.4 Care shall be exercised to ensure that all tubing is securely retained in the support system. This will include additional tie-downs within 300 mm (12 in) of the tubing connection to any instrument or valve and within 300 mm (12 in) on each side of a tube union installed in any location normally accessible to operating personnel.
10.3.5 A support system in accordance with this specification shall be provided for all field installed tubing and tube bundles, even if the construction drawings do not show the support system or show only a portion of it.
10.3.6 All tubing, when leaving a support system, will be secured to prevent movement.
- INSTRUMENT AIR PIPING
11.1 The instrument contractor shall furnish, fabricate, and install all instrument air piping not installed by the general contractor in accordance with the contract drawings and the construction specification. Material selection will be per 4API-630292.
11.2 The contractor shall furnish and install pipe supports and galvanized clamps as required to firmly secure the piping. Unsupported spans shall not exceed 3000 mm (10 ft) for DN 12 mm (1/2 in NPS) and DN 19 mm (3/4 in NPS) pipe and 4570 mm (15 ft) for DN 25 mm (1 in NPS).
11.3 The contractor shall route pipe and install all supports in a manner that does not obstruct the operation, maintenance or removal of equipment, instruments, panels, overhead cranes, walkways, platforms, ladders or stairs, and areas less than 2285 mm (7 ft 6 in) above walk/access ways.
11.4 All threaded systems shall be pressure tested to 6.9 bar g (7 kg/cm2) (100 psig) for leaks. Any fittings found to be leaking will be back-welded to ensure a leak-free system.
- TUBE CLEANING
12.1 To prevent intrusion of contaminants such as dust, dirt, sand, water, and oil materials, all tubing ends shall be kept closed or capped at all times except during installation.
12.2 All instrument air control and supply tubing lines installed by the contractor shall be thoroughly blown down over their full length. Blowdown gases such as bottled nitrogen or bottled air shall be used for the blowdown. Refer to 4WPI-SW70001 for additional information.
12.3 All process and analyzer tubing lines installed by the contractor shall be flushed from the source to the end of the run. The cleaning agent shall be a commercial grade of a type approved by Air Products and shall be compatible with the materials being cleaned. Refer to 4WPI-SW70002 for additional information.
12.4 All oxygen decontaminated process and analyzer tubing/fittings shall be hydrocarbon decontaminated for oxygen service. All components installed within the tubing run must be acceptable for use in oxygen service. All process tubing shall be cleaned in accordance with 4WPI-SW70003.
12.5 All fluorine decontaminated process and analyzer tubing/fittings shall be hydrocarbon decontaminated for fluorine service. All components installed within the tubing run must be acceptable for use in fluorine service. All process tubing shall be cleaned in accordance with 4WPI-SW70004.
12.6 Quality control documents: All lines shall be certified by the contractor and witnessed by the Air Products representatives as having been properly cleaned and having point-to-point checks verified by the blowdown or flushing of the various lines.
- PRESSURE TESTING
13.1 The instrument contractor shall pressure test all installed tubing. All process tubing will be tested at a minimum of 6.9 bar g (100 psig). Higher pressures might be required. Actual operating pressures will be furnished by Air Products.
13.1.1 Pressure testing of all analyzer lines will be witnessed by the Air Products representative. All other pressure testing verification will be done on a random basis by the Air Products representative.
13.1.2 All tubing (process and analytical) shall be visually inspected for leaks using only ammonium-free leak detection fluid. Omega 31, manufactured by US Gulf Corporation, is the only solution approved by Air Products.
13.2 All instrument air regulators shall be backed off to mid-range, supply valves shall be closed, and low point plugs removed for the initial blowdown of each air header branch line. Each branch line shall then be pressure tested at operating pressure and visually inspected for leaks using Omega 31 leak detection fluid.
13.2.1 The air supply to each individual instrument shall be disconnected and blown down before initial admission of instrument air.
- PATCHING, REPLACEMENT, AND MODIFICATION OF EXISTING WORK
14.1 After installation the contractor shall neatly patch, repair, and/or replace existing work which has been damaged, removed, or altered by performance of the work. Work shall be similar and equal in quality to the work removed and/or damaged unless otherwise shown or specified. Such work includes, but is not limited to, patching and/or replacement of existing masonry, siding, roofing, partitions, and painting.
14.2 The contractor shall seal all wall penetrations used for instrumentation with silicone RTV or approved barrier system.
- SAFETY
15.1 The contractor shall adhere to all the construction safety procedures specified in 4WCE-670200.
- MOUNTING OF INSTRUMENTS
16.1 All pipe, angle, plant and hardware shall conform to 4ACS-640131.
16.2 All instrument stands and racks 1800 mm (6 ft) or less in length shall be galvanized per 4ACS-640131, Section 9.5. Instrument racks longer than 1800 mm (6 ft) in length shall be galvanized per 4ACS-640131, section 9.5 or painted per 4WEQ-6804.
16.3 Painted racks shall have finish coats applied before mounting instrument and/or hardware. Touch-up of damaged coating shall be per 4WEQ-6804.
16.4 All DN 50 mm (2 in NPS) diameter pipe instrument supports shall be capped, and a 3 mm (1/8 in) diameter low point drain hole shall be provided.
16.5 All instrument supports shall be rigid and free of excessive vibration.
16.5.1 If instruments must be mounted in an area of possible vibrations, the stands shall be mounted on vibration isolators, McMaster-Carr; felt vibration damping pads, No. 5980K or equal.
16.6 Instrument support stands and racks shall be of all welded construction.
16.7 The instrument contractor shall ensure that all instruments mounted on or near the cold box will not interfere with the cold box maintenance or field piping and will be mounted at a serviceable location. If an alternate location is required, consult with the Air Products representative.
16.8 The typical elevation of 1370 mm (4 ft 6 in) above finished grade or platform grating shall be maintained unless otherwise detailed on the contract drawings.
16.9 All instruments shall be mounted such that the conduit connection is on the side or, ideally, at the bottom. The contractor shall follow the manufacturer’s mounting procedure. Under no circumstances shall the conduit connection be directed upwards.
16.10 Prefabricated instrument supports may be substituted in place of fabricated if the contractor can show a cost savings. One-piece supports are preferred over modular units.
- ANALYZER CALIBRATION GAS CYLINDER SUPPORT RACK
17.1 The instrument contractor shall fabricate a cylinder support rack or racks per the contract drawings. Location of the rack or racks shall be defined on the instrument location drawings.
17.2 All analyzer calibration gas cylinders shall be installed in the position identified on the instrument location drawings and tubed per the instrument tubing hook-up details.
17.3 Analyzer manifold-regulators shall be installed by the instrument contractor on the cylinder rack with the related gas cylinder or cylinders as defined on the contract drawings.
17.4 The instrument contractor’s responsibility of work ends at the analyzer panel or panels unless otherwise indicated on the contract drawings.
17.5 The instrument contractor will not be responsible for supplying analyzer calibrations gas cylinders or manifold regulators.
- WELDING AND BRAZING OF TUBING
18.1 Air Products will not accept brazing as a method of connecting copper tubing in the field unless otherwise specified on contract drawings. The instrument contractor must get approval from the Air Products field instrumentation representative.
18.2 The instrument contractor shall socket weld all stainless steel tubing defined on the hook up details per 4ACS-640131.