Corpus sync: neutrality remakes, note hygiene, datasheet relocation, transformer-split cross-refs
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title: Instrument Installation and Impulse Tubing
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### Tap orientation and impulse-line slope shall be coordinated so that liquid-filled lines self-vent toward the instrument and gas or steam lines drain condensate back toward the process tap.
−### Tap orientation is a measurement-integrity decision, not just a routing choice: for a liquid-filled line the instrument must sit above the tap so trapped gas vents back to the process, while for a gas or steam line the instrument must sit below so condensate drains back to the tap. {note}
+### Tap orientation is a measurement-integrity decision, not just a routing choice: for a liquid-filled line the instrument must sit above the tap so trapped gas vents back to the process, while for a gas or steam line the instrument must sit below so condensate drains back to the tap.
### Reversing the correct slope direction traps gas in a liquid leg or liquid in a gas leg and introduces a systematic, offset error that calibration cannot remove. {note}
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### The manifold type is set by the measurement: a single-pressure (gauge) instrument needs a 2-valve block-and-bleed; a differential-pressure instrument needs a 3-valve manifold to equalize and isolate both legs; a DP instrument that requires in-situ calibration with dual-side bleed needs a 5-valve manifold. {note}
−### Omitting the manifold type and mount style from the specification forces a substitution RFI in the field; the Engineer shall state valve count and integral-versus-remote mount explicitly. {note}
+### Omitting the manifold type and mount style from the specification forces a substitution RFI in the field; the Engineer shall state valve count and integral-versus-remote mount explicitly.
```datasheet
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### Manifold port size and thread form shall match the connected instrument and tubing, without adapters added in the field.
−### Many manifolds ship with 1/2 in. NPT or SAE ports while the specified instrument uses 1/4 in. NPT; an unspecified port size forces field adapters that add leak points, so the port size shall be stated explicitly. {note}
−
```datasheet
label: Manifold Process / Instrument Port Size
…6 unchanged lines
```
+### Many manifolds ship with 1/2 in. NPT or SAE ports while the specified instrument uses 1/4 in. NPT; an unspecified port size forces field adapters that add leak points, so the port size shall be stated explicitly. {note}
+
# Impulse Tubing and Piping {toc}
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### Impulse tubing shall be of a material compatible with the process fluid, temperature, and corrosion allowance, conforming to the applicable ASTM specification.
−### Stainless impulse tubing shall conform to ASTM A269/A269M; alloy-steel high-temperature tubing to ASTM A213/A213M; carbon-steel tubing to ASTM A179; and copper instrument-air tubing to ASTM B88.
−
−### The 80% case for process and water/wastewater service is 316L stainless steel, chosen for broad corrosion resistance and ready availability; chloride-bearing service (seawater, brine, high-chloride wastewater) moves to duplex, and high-temperature steam moves to carbon or alloy steel. {note}
−
```datasheet
label: Impulse Tubing Material
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```
+### Stainless impulse tubing shall conform to ASTM A269/A269M; alloy-steel high-temperature tubing to ASTM A213/A213M; carbon-steel tubing to ASTM A179; and copper instrument-air tubing to ASTM B88.
+
+### The usual material for process and water/wastewater service is 316L stainless steel, chosen for broad corrosion resistance and ready availability; chloride-bearing service (seawater, brine, high-chloride wastewater) moves to duplex, and high-temperature steam moves to carbon or alloy steel. {note}
+
## Tubing Size and Wall {toc}
### Tubing OD and wall thickness shall be selected so the tubing pressure rating meets or exceeds the process design pressure at design temperature.
−### A minimum wall thickness shall be specified for each service; thin-wall tubing (0.028 in.) shall not be substituted.
−
−### Some contractors will source cheaper thin-wall tubing when no minimum wall is stated; thin-wall tubing cannot meet the design pressure at elevated temperature and is a latent rupture hazard, so the wall is specified, not left to the supplier. {note}
−
```datasheet
label: Impulse Tubing OD and Wall
…6 unchanged lines
```
−### Tubing pressure rating, 316L stainless 1/4 in. OD × 0.049 in. wall, at 100°F is approximately 5,500 psi per ASME B31.3 / PIP PCSIP001, derated by the temperature correction factor above 100°F. {note}
−
−### Tubing pressure rating, 316L stainless 1/2 in. OD × 0.083 in. wall, at 100°F is approximately 6,600 psi at 100°F. {note}
−
```datasheet
label: Process Design Pressure
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```
+### A minimum wall thickness shall be specified for each service; thin-wall tubing (0.028 in.) shall not be substituted.
+
+### Some contractors will source cheaper thin-wall tubing when no minimum wall is stated; thin-wall tubing cannot meet the design pressure at elevated temperature and is a latent rupture hazard, so the wall is specified, not left to the supplier. {note}
+
+### Tubing pressure rating, 316L stainless 1/4 in. OD × 0.049 in. wall, at 100°F is approximately 5,500 psi per ASME B31.3 / PIP PCSIP001, derated by the temperature correction factor above 100°F. {note}
+
+### Tubing pressure rating, 316L stainless 1/2 in. OD × 0.083 in. wall, at 100°F is approximately 6,600 psi at 100°F. {note}
+
## Slope and Routing {toc}
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### Tube fittings shall be selected for the service pressure class, vibration exposure, and maintainability.
−### Double-ferrule compression fittings shall be used for general process and water/wastewater service.
−
−### NPT threaded fittings shall not be used as the primary connection method in high-cycle vibration service (reciprocating compressors and pumps); compression or socket-weld fittings shall be used there.
−
−### Vibration loosens tapered NPT threads over time, so high-cycle vibration service demands the mechanical retention of a compression or socket-weld joint rather than thread engagement alone. {note}
−
```datasheet
label: Tube Fitting Type
…6 unchanged lines
```
+### Double-ferrule compression fittings shall be used for general process and water/wastewater service.
+
+### NPT threaded fittings shall not be used as the primary connection method in high-cycle vibration service (reciprocating compressors and pumps); compression or socket-weld fittings shall be used there.
+
+### Vibration loosens tapered NPT threads over time, so high-cycle vibration service demands the mechanical retention of a compression or socket-weld joint rather than thread engagement alone. {note}
+
### Compression fittings shall be made up to the manufacturer's initial make-up specification (for example, 1-1/4 turns past finger-tight for a 1/4 in. fitting) and the made-up connection shall be marked and verified at installation.
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# Installation {toc}
−## General {toc}
+## Instrument tubing and piping shall be installed in accordance with the approved hook-up drawings, the tubing manufacturer's instructions, and PIP PCCIP001 / ANSI/ISA-77.70.
−### Instrument tubing and piping shall be installed in accordance with the approved hook-up drawings, the tubing manufacturer's instructions, and PIP PCCIP001 / ANSI/ISA-77.70.
+## Tubing shall be cut square, deburred, and blown clear before fittings are made up.
−### Tubing shall be cut square, deburred, and blown clear before fittings are made up.
+## Bends shall be made with a proper tube bender to the manufacturer's minimum bend radius, without flattening or kinking the tube.
−### Bends shall be made with a proper tube bender to the manufacturer's minimum bend radius, without flattening or kinking the tube.
+## Instrument air supply tubing and impulse (sensing) tubing shall be installed as separate systems, with their own materials, ratings, and cleanliness requirements.
−### Instrument air supply tubing and impulse (sensing) tubing shall be installed as separate systems, with their own materials, ratings, and cleanliness requirements.
+## Confusing instrument-air tubing with impulse tubing is a recurring error; the two carry different service, pressure, and cleanliness requirements and shall not share materials or runs even where they parallel each other. {note}
−### Confusing instrument-air tubing with impulse tubing is a recurring error; the two carry different service, pressure, and cleanliness requirements and shall not share materials or runs even where they parallel each other. {note}
−
## Cleanliness {toc}
### Tubing bores shall be kept clean and capped during storage and installation, and shall be free of cutting oil, chips, and debris before connection to the instrument.
−### Oxygen and other special-cleanliness services shall be cleaned and handled to the project cleanliness specification before installation. {note}
+### Oxygen and other special-cleanliness services shall be cleaned and handled to the project cleanliness specification before installation.
# Delivery, Storage, and Handling {toc}
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### Materials shall be stored indoors or under cover, off the ground, and protected from moisture, dirt, and mechanical damage until installed.
−### Stainless tubing shall be stored away from carbon-steel storage that could transfer iron contamination to the stainless surface. {note}
+### Stainless tubing shall be stored away from carbon-steel storage that could transfer iron contamination to the stainless surface.
# Warranty {toc}
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### Ferrule sets and manifold seal kits are the wear items most likely to be needed for a re-make or a packing replacement, so a small field stock keeps a single leak from becoming a procurement delay. {note}