Sanhua SHF(L)-4H-23U-52 4-Way Reversing Valve – 5/16"→3/8", Kv 1.6, Inverter Compatible, Without Coil

Sanhua SHF(L)-4H-23U-52 is a 4-way valve that reverses the cycle in heat pumps and in systems providing both heating and cooling. Its inlet is 5/16" ODF and its other three connections are 3/8" ODF solder.

Reverses the Cycle in a Heat Pump — Also Suitable for Systems with Inverter Compressors

The 4-way valve determines which heat exchanger the compressor's discharge gas is sent to. In the cooling position the outdoor unit is the condenser and the indoor unit is the evaporator; when the valve changes position, the roles are reversed and the same circuit provides heating. The defrost cycle is also carried out with this valve.

This model is in Sanhua's "Variable & Fixed Speed" class — meaning it can also be used in systems with variable-speed (inverter) compressors. In inverter systems, the differential pressure in the system decreases when the compressor runs at low speed; in this series the minimum differential pressure required for the valve to change position has been reduced to 0.1 MPa (1 bar). In the old -51 series this value was 0.25 MPa — the real cause of failure to reverse at low speed.

Technical Specifications (Official Sanhua Datasheet, Table 1)

• Model: Sanhua SHF(L)-4H-23U-52 | Part no: 10180952502
• System type: Variable & Fixed Speed — inverter and fixed-speed systems
• Connection ØD: 5/16" ODF solder | ØE / S / C: 3/8" ODF solder
• Port diameter: 8.0 mm | Kv value: 1.6 m³/h
• Max. operating pressure (MOP): 4.7 MPa = 47 bar
• Operating pressure differential (OPD): min 0.1 MPa · max 4 MPa
• Medium temperature (TS): −30 … +135 °C | Ambient temperature: −30 … +50 °C
• Net weight: 0.2 kg · dimensions 94.4 × 43 × 50 mm
• Certificate: UL / CSA · PED Article 4.3 (Fluid Group 1 and 2)
• Compatible refrigerants: R22 · R134a · R404A · R407C · R410A · R507 · R450A/R513A · R32 · R290 · R1234ze(E) · R1234yf

🚨 Coil Not Included

Sanhua 4-way valves are sold without a coil. The valve operates by gas pressure; electricity goes only to the coil that drives the pilot valve, which determines the direction. The coil is selected separately according to the supply voltage:

• 🔧 Mounting position: Sanhua's instruction is clear — the valve is mounted with the coil facing up or with the body axis horizontal. The flow direction is set according to the installation instructions.
• ⚠️ Brazing warning: the body is thin-walled and contains a Teflon slide. While brazing, wrap the body in a wet cloth and do not point the flame directly at the body — excessive heat permanently seizes the slide.
• Fault diagnosis: if the valve does not change direction, check in order — (1) is the coil winding intact, (2) is voltage reaching the coil, (3) is there a differential pressure of at least 0.1 MPa in the system. If all three are fine, the problem is in the pilot valve.
• Need more capacity? The next size up is SHF(L)-7H-34U-52 (3/8"→1/2", Kv 2.9), and the one above that is SHF(L)-11H-35U. This model is the smallest size in the series.