Sanhua RFKH08E-6.1-318A Thermostatic Expansion Valve – R448A/R449A, External Equalizer, MOP −10 °C, Brazed

Sanhua RFKH08E-6.1-318A is an externally equalized (E) thermostatic expansion valve with MOP function, operating with R448A / R449A refrigerants. It is specified for the −40 … −15 °C evaporating range — low temperature applications (freezers, blast chillers, low temperature cold rooms).

Externally Equalized Valve with MOP — Protects the Compressor Motor from Overload at Start-Up

MOP (Maximum Operating Pressure) does not allow the evaporating pressure to exceed a set value. When the system starts warm or restarts after defrost, the suction pressure rises rapidly; at this moment the motor is loaded above its design current. This valve throttles the flow above the pressure corresponding to a saturation temperature of −10 °C and prevents the compressor from drawing excessive current.

The external equalizer (E) takes into account the pressure drop inside the evaporator. On evaporators with long circuits or distributors, an internally equalized valve reads superheat higher than it is and throttles the valve unnecessarily; since the external equalizer line carries the outlet pressure directly to the valve, superheat is controlled from its true value.

Technical Specifications (Official Sanhua Datasheet R2511, Tab. C)

• Model: Sanhua RFKH08E-6.1-318A | Sanhua part no.: 10201036402
• Refrigerant: R448A / R449A
• Nominal capacity: 6.1 USRT (≈ 21.5 kW)
• Evaporating range: −40 … −15 °C (Range NL) · MOP = −10 °C
• Equalizer type: external equalizer
• Connections: inlet 3/8" flare · outlet 1/2" ODF (solder) · equalizer line 1/4" ODF (solder)
• Max. working pressure (MWP): 4.6 MPa = 46 bar (665 psig)
• Ambient temperature (TS): −40 … +70 °C
• Bulb and capillary tube: stainless steel · capillary tube length 1.5 m
• Thermal charge: cross charge — superheat remains consistent even as the evaporating temperature changes
• Certification: UL / CSA · PED declaration

🚨 Scope of Delivery — Orifice Not Included

Sanhua's datasheet itself notes: "Extent of delivery: valve body and bulb strap" — the box contains the valve body + bulb strap. The orifice that determines the capacity is ordered separately. Without an orifice the valve does not pass refrigerant; do not forget the orifice when ordering.

Orifice Capacities for R448A (kW)

• 🔑 Reading the code: RFKH | 08 | E | 6.1 | 318A → 08 refrigerant code (R448A/R449A) · E external equalizer · 6.1 nominal capacity in USRT · 318A connection and version digits. The final A indicates the current generation.
• 🔧 Bulb placement: on the upper half of the horizontal suction line (10 or 2 o'clock position), before, not after any liquid trap. The bulb must always be insulated; otherwise the ambient temperature distorts the reading.
• 🔧 The external equalizer line is a 1/4" tube and is connected downstream of the bulb. Leave a bend in the line to prevent oil from entering the equalizer line.
• ⚠️ Brazing warning: wrap the valve body in a wet cloth when brazing; excessive heat damages the internal seal and the thermostatic element.
• Version without MOP: RFKH08E-6.1-52A (−40 … +10 °C, no MOP) with the same connections is available in our catalog. If you have no low temperature application and do not need MOP protection, that version is sufficient.