The York S1-1TVM4G1 (3918, 26318-2-F) Thermostatic Expansion Valve is a high-performance R-410A refrigerant metering device designed for precise control of refrigerant flow in York air conditioning and heat pump systems. Featuring a durable brass body with 5/8" male x 5/8" female fittings, this single-port (SP) valve maintains stable superheat levels for improved system efficiency and performance. Key Features: Genuine York OEM expansion valve for R-410A systems. Provides accurate refrigerant control for optimal cooling performance. 5/8" male x 5/8" female connections for easy installation. Ensures efficient superheat regulation and consistent temperature control. Robust construction for long-lasting reliability in demanding conditions. Specifications: Part Number: S1-1TVM4G1 Alternate Part Numbers: 3918, 26318-2-F Refrigerant Type: R-410A Connection Size: 5/8" Male x 5/8" Female Type: Single Port (SP) Function: Thermostatic expansion valve (TXV) Manufacturer: York Compatible Models: AHP30B4GH21, AHP36C4GH21, 2EE04703324, AC3B060F1, 1SP0451, 1NP0806, B1HH060A25FE, FC36A4GN1, MC36C4GH1, E2RC060S06, LHJD24S41S2, MC35B4GH1, and more. Why Choose This Item: The York S1-1TVM4G1 TXV ensures precise refrigerant flow control and optimal energy efficiency for R-410A systems. As an authentic OEM part, it provides perfect compatibility, superior performance, and reliability, restoring factory specifications and system balance for your York HVAC equipment.