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Overview
The Danfoss SGP 6s N (014L0181) is a 1/4" ODF × ODF solder-connection sight glass with a high-precision N-type color moisture indicator, designed for installation in the liquid line of refrigerating systems. Part of Danfoss's established SGP (high-pressure) product family, it is rated to 52 bar / 754 psig maximum working pressure — significantly higher than the standard SG series — making it appropriate for use with modern high-pressure refrigerants including R32, R410A, R452B, R454B, R1234yf, R1234ze(E), and CO₂ in secondary/cascade loops. Its brass body provides excellent corrosion resistance verified to 2,000 hours salt spray per ASTM B117.
The N-type moisture indicator uses a paper element impregnated with a color-sensitive compound that transitions from green (dry/safe) to yellow (wet/replace drier) as refrigerant moisture content rises. This allows the technician or system designer to assess system health at a glance — green indicates the refrigerant moisture is well within specification, an intermediate (fading green) color signals the drier is approaching saturation, and a solid yellow indicates the drier must be replaced immediately. Bubbles visible through the glass window (instead of a clear liquid column) indicate insufficient subcooling or refrigerant loss, giving the operator two independent diagnostic signals in a single component.
The SGP 6s N is the correct choice for compact, high-efficiency refrigeration circuits — including mobile HVAC/R, packaged chillers, heat pumps, and cold-room systems — where 1/4" line sizing and ODF solder connections are used with HFC, HCFC, or HFO refrigerants. It is UL 207 listed and conforms to the Pressure Equipment Directive (PED) 2014/68/EU, and appears in Kippkitts assemblies wherever liquid-line monitoring is required for R134a, R290, R32, and related refrigerant circuits.
Note on moisture indicator chemistry (REACH): The N-type indicator element contains paper impregnated with Cobalt Dichloride (CAS 7646-79-9) at >0.1% w/w. The paper is enclosed within the sealed body during normal service. If the sight glass is damaged or dismantled, avoid skin contact with the element and dispose of the paper as hazardous waste per local regulations.
Key Specifications
| Parameter | Value |
|---|---|
| Manufacturer | Danfoss |
| Model / Type | SGP 6s N |
| Part Number | 014L0181 |
| Component Type | Sight glass with N-type moisture indicator |
| Series | SG / SGP — Refrigeration System Protectors |
| Connection Type | Solder ODF × ODF |
| Connection Size | 1/4 in. (6.35 mm OD) |
| Max. Working Pressure (MWP/PS) | 52 bar / 754 psig |
| Media Temperature Range | −50 to +80 °C / −58 to +175 °F |
| Storage / Transport Temp. | −40 to +65 °C / −40 to +150 °F |
| Storage / Transport Humidity | RH ≤ 95% |
| Moisture Indicator Type | N-type (green = dry, yellow = wet); white indicator fixture |
| Compatible Refrigerant Groups | A1: R134a, R22, R404A, R407A/C/F/H, R410A, R448A, R449A, R450A, R452A, R463A, R507A, R513A, R515B, R1233zd(E) |
| A2L: R32, R452B, R454B, R454C, R455A, R1234ze(E), R1234yf | |
| A3: R1270 | |
| R744 (CO₂) — secondary loop / cascade | |
| Compatible Refrigerant Oils | POE, PVE, PAG, PAO; Mineral oils |
| Body Length (L) | 101 mm |
| Tube Length (L1) | 7 mm (each side) |
| Body Height (H) | 24 mm |
| Viewing Window Height (H1) | 15 mm |
| Body Width (B1) | 14 mm |
| Body Diameter (øD) | 27 mm |
| Tube OD Tolerance | +0.065 / +0.155 mm |
| Net Weight | 0.1 kg |
| Body / Valve Material | Brass |
| Connection Tube Material | Copper |
| Seal Material | PTFE (Teflon ring) |
| Spring Material | Stainless steel |
| Glass | Borosilicate-type viewing glass |
| Country of Origin | China |
| Corrosion Resistance | 2,000 hrs salt spray (ASTM B117) |
| Certifications | UL 207, PED 2014/68/EU, RoHS, China RoHS, EN ISO 14903:2017 Level A1/B1, CRN (Canada/TSSA), EAC |
Moisture Indicator Reference — N-Type (Color Thresholds)
All values in ppm (parts per million by weight). Representative refrigerants shown; see Danfoss datasheet for full table.
| Refrigerant | Green / Dry @ 25 °C | Intermediate @ 25 °C | Yellow / Wet @ 25 °C | Green / Dry @ 43 °C | Yellow / Wet @ 43 °C |
|---|---|---|---|---|---|
| R134a | < 30 | 30 – 100 | > 100 | < 45 | > 170 |
| R32 | < 64 | 64 – 289 | > 289 | < 116 | > 459 |
| R404A | < 20 | 20 – 70 | > 70 | < 25 | > 100 |
| R410A | < 66 | 66 – 266 | > 266 | < 135 | > 540 |
| R448A | < 28 | 28 – 110 | > 110 | < 70 | > 227 |
| R449A | < 29 | 29 – 105 | > 105 | < 53 | > 200 |
| R452B | < 70 | 70 – 260 | > 260 | < 144 | > 260 |
| R454B | < 29 | 29 – 161 | > 161 | < 58 | > 250 |
| R1234yf | < 20 | 20 – 43 | > 43 | < 20 | > 63 |
| R1234ze(E) | < 26 | 26 – 132 | > 132 | < 28 | > 165 |
| R744 (CO₂) | < 80 | 80 – 195 | > 195 | — | — |
Thresholds vary with media temperature. Consult Danfoss for refrigerants and temperatures not listed.
Integration Notes
- Installation position: Mount in the liquid line between the filter drier and the expansion device (TXV or EEV). Do not install upstream of the filter drier — the drier must condition the refrigerant before the moisture indicator reads meaningful values.
- Solder joint procedure: The 1/4" ODF copper tubes accept standard refrigeration brazing practice. Ensure the body does not exceed solder temperature limits; shield the glass window and indicator element from direct flame. Purge with dry nitrogen during brazing per industry best practice.
- Bubble interpretation: A steady stream of bubbles under normal operating conditions (not startup) indicates insufficient subcooling or a low refrigerant charge. Transient bubbling at startup is normal and will clear as the system reaches steady state.
- Indicator at startup: The N-type element may read yellow at initial startup due to residual air humidity in the circuit. As the filter drier processes the refrigerant charge, the indicator will transition to green, confirming moisture has been reduced to acceptable levels. If it does not return to green, the drier is saturated and must be replaced before continued operation.
- Oil line restriction: This model (with N-type indicator) is not suitable for oil-line monitoring. For oil-line or compressor-sump sight glass applications, use the no-indicator SGP variant or contact Danfoss.
- R290 / flammable refrigerants (A2/A3): This solder ODF × ODF connection type is approved for A1 and A2L refrigerants only. Solder and flare connections carry higher leak risk and are not approved for A2 (e.g., R290, R600a) refrigerants per Danfoss ignition-source safety assessment. Use socket-type SGP for flammable refrigerants.
- CO₂ / R744: Suitable for R744 in secondary loop or cascade configurations. Ensure system-level pressure relief sizing is adequate, as R744 can pressurize rapidly when de-energized. This component has no built-in pressure relief.
- Avoid moisture contamination during storage: Keep the sight glass sealed and away from non-refrigerant liquids (water, oil) until installation. Moisture contact with the indicator element prior to installation will give a false wet reading.
- MTBF/L10 life: Not specified in the published Danfoss datasheet. Contact Danfoss directly if long-life qualification or MTTF data is required for your application