Installation details must be reviewed by the Process Control Engineer.ħ. External connections to the reset bellows (ECRB) on local pneumatic controllers are not shown on the flowsheet and must be identified by reviewing the controller specification.When a single pneumatic signal is controlling two or more process variables, an isolating block valve must be installed on each circuit for service and maintenance purposes.For pneumatic-signal outputs on field instruments, a tubing tee with a fitting plug shall be installed, for calibration purposes, as close as possible to the instrument.A male pipe weld connector shall be used at all socket-welded valves. All root valves will have socket weld connections for installation of a “male pipe weld connector.”ĥ.13 Tubing containing combustible or toxic gases shall have welded connections, whenever possible. The connection to the field instrument shall be threaded unless otherwise indicated by the instrument specification. Check heat tracing requirements.ĥ.12 Process tubing for hydrocarbon gases shall be designed with no threaded joints. Check heat tracing requirements.ĥ.11 When mounting instruments for liquid service (for example, cooling water), the instrument shall be mounted below the tap with the tubing sloping toward the instrument. If above mounting can’t be avoided, a siphon shall be installed at the process connection with the instrument mounted above the tap to keep live steam from overheating the instrument.ĥ.10 For instruments mounted below a process line containing steam, a fill tee shall be installed in the tubing so that the line can be filled with water for protection of the instruments. Heat-tracing might be required to avoid freezing (see paragraph 5.7).ĥ.9 In most steam process applications, avoid mount instruments above the process connection. Consult with Project Engineering for heat-tracing requirements.ĥ.8 Any process tubing which might accumulate condensation in the line, requires condensate traps at the low point of the tubing run to the instrument. Depending on site location, insulation and/or heat- tracing may be eliminated. Check with Project Engineering for site conditions.ĥ.7 When instruments can be mounted above a condensable-vapor line, the tubing must be sloped to the process line, avoiding any low points. Heat tracing and enclosures shall be used only when freeze protection is required by ambient conditions. Single isolation valves should have a mechanical locking device.ĥ.6 For projects that have a pressure and flow transmitter in a condensable vapor line and the instruments are mounted below the piping process connection, the instrument tubing shall be electrically heat traced and the instruments shall be mounted in a heated enclosure or an insulated covering. All manifolds shall be cleaned per Oxygen Clean (Class AA) Inspection and Acceptance Requirements.ĥ.5 For critical circuits when the flowsheet identifies a “lock open” (LO) or “lock closed” (LC) valve within the instrument connection tap, the manifold valve must be specified with removable Anti- Tamper bonnet that can be locked into position. All two- valve manifolds shall be cleaned per Oxygen Clean (Class AA) Inspection and Acceptance Requirements.ĥ.4 Differential-pressure instruments shall include a 3-valve manifold when used on pressures of 10 bar g (150 psig) and below, and a 5-valve manifold for pressures over 10 bar g (150 psig). Any special diagrams shall be generated using the standard format.Ĥ.2 A cover sheet and general notes shall be released with all instrument hookup detail packages.Ĥ.3 Each hookup diagram shall be shown schematically with all fittings, valves, and tubing, referred to by the bill of material item number.Ĥ.4 Instruments with similar hookup details shall be included on one diagram to eliminate multiple diagrams containing identical content.ĥ.1 All instrument process tubing sizes, wall thicknesses, pressure ratings, fittings, and valves shall be selected from the information in 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, Bundled Tubing for Instrument Service, and Electrically Traced Tubing for Instrument Service.ĥ.2 Tubing for oxygen or ultrahigh-purity (UHP) service shall be hydrocarbon decontaminated (Class AA clean) as defined by Oxygen Clean (Class AA) Inspection and Acceptance Requirements.ĥ.3 All process tubing to a Gage pressure-measuring instrument shall include a two-valve manifold installed between the process root valve and the instrument, located at the instrument. Instrument Tubing Hook-Up Detail Analyzer Sample Moisture Removal EnclosureĤ.1 All instrument hookup diagrams shall be per standard instrument design details.