Sanhua SYJ10H51 Sight Glass – 3/8" ODF Solder, with Moisture Indicator, 46 bar

Sanhua SYJ10H51 is a 3/8" (10 mm) ODF solder sight glass installed in the liquid line of a refrigeration circuit. Its ring-type color indicator shows the moisture level in the system.

Shows Two Things at Once in the Liquid Line — Refrigerant Condition and Moisture Level

First task — refrigerant condition. When viewed through the glass, the liquid should appear clear. If bubbles are visible, either the charge is low or there is a restriction ahead of the expansion valve. This is the quickest way to check the charge in the field.

Second task — moisture. Moisture entering the circuit combines with the refrigerant and oil to produce acid. When the indicator color changes from green to yellow, the filter drier is saturated — it is replaced before the compressor is damaged.

Technical Specifications (Official Sanhua SYJ Series Datasheet)

• Max. working pressure (PS): 4.6 MPa = 46 bar
• Medium temperature (TS): −50 … +80 °C | Ambient temperature: −50 … +80 °C
• Body: corrosion-resistant brass | Sealing: low-creep PTFE
• Indicator: ring-type moisture color indicator, bonded to the glass (prevents surface contamination)
• Passage: full port — low pressure loss · wide-angle, high-clarity glass
• Certificate: PED 2014/68/EU Article 4.3 (Fluid Group 2) · ANSI-ASHRAE 34 Group A1
• Compatible refrigerants: R22 · R134a · R404A · R410A · R507 · R407C · R407A/F · R448A/R449A · R452A · R450A/R513A

• 🔧 Location: installed in the liquid line AFTER the filter drier. It can also be used in the suction line.
• 🔧 Mounting position: Sanhua recommends a vertical line. If it is to be fitted in a horizontal line, the glass must face upward and must not be tilted in any direction — with tilted mounting the indicator reads incorrectly.
• ⚠️ Brazing warning: wrap the body in a wet cloth when brazing. Excessive heat permanently damages both the PTFE seal and the color agent of the moisture indicator.
• Reading the color: GREEN = dry · YELLOW = wet (filter drier saturated, replace it). The color change is not instantaneous; read it after waiting at least 12 hours with the system running.
• Bubbles do not always mean a low charge. A restriction ahead of the expansion valve, a blocked filter drier or insufficient subcooling also cause bubbles.