Danfoss NRVH 16s Check Valve (020B1038) – 5/8" ODF Straightway Brazed, Strong Spring 0.20 bar, Kv 4.00

The Danfoss NRVH 16s (code 020B1038) is a check valve that allows refrigerant to flow in one direction only and prevents reverse flow. With its piston design and brass body, it has a 5/8" (16 mm) ODF straightway brazed connection.

NRV or NRVH? The Difference Is the Opening Pressure: 0.20 bar, Not 0.02 bar

Danfoss offers two versions of the same body and mixing them up is a common mistake:

• NRV 16s (020B1018): opening pressure 0.02 bar — light spring, normal applications
• NRVH 16s (020B1038) — this product: opening pressure 0.20 bar — strong spring

Danfoss recommends the NRVH version for use in parallel-connected compressors (power packs), i.e. in discharge lines where high vibration and pressure pulsation are expected. The strong spring prevents the valve from opening and closing with shocks and pulsation (chattering); the life of the valve plate and leak-tightness are preserved. The Kv value is 4.00 m³/h in both versions — the difference is not capacity but the spring.

⚠️ Choose the right version: Using an NRVH in a normal single-compressor circuit creates an unnecessary pressure drop; using an NRV in a discharge line with parallel compressors wears the valve out early.

Technical Specifications (Official Danfoss Data Sheet)

• Model: Danfoss NRVH 16s v2 | Code: 020B1038 | NRV equivalent: 020B1018
• Connection: 5/8" (16 mm) ODF brazed, straightway — inlet and outlet on the same axis
• Opening Pressure (Min. OPD Δp): 0.20 bar (2.90 psi)
• Kv: 4.00 m³/h | Cv: 4.62 gal/min
• Max. Working Pressure (PS): 49 bar (710 psig)
• Temperature Range: −50 … +155 °C
• Material: Brass body · copper internal connections · piston design
• Dimensions: L 139 mm · L1 12 mm · ØD 28 mm | Net weight: 0.16 kg — official dimension drawing in the 2nd image
• Approved Refrigerants: R22, R134a, R404A, R407A/C/F/H, R410A, R448A, R449A/B, R450A, R452A, R507A, R513A, R515B, R516A and the flammable refrigerants R32, R290, R1270, R170, R600, R600a, R454A/B/C, R455A, R1234yf, R1234ze(E), R1233zd(E)
• Approvals: cULus Listed · EAC · UA | EAN: 5702428572033

• 🔧 Always verify the flow direction. The arrow on the body shows the direction the refrigerant must flow. A check valve fitted in reverse blocks the system completely.
• Cool the body with a wet cloth during brazing and use a nitrogen purge; excessive heat damages the internal seal and piston surface.
• Horizontal mounting in the discharge line is preferred; with vertical mounting, make sure the flow direction is upward.
• The opening pressure is part of the system calculation: take the additional 0.20 bar pressure drop into account in your condenser line calculation.
• Since it can operate down to −50 °C, it can also be used in low-temperature applications.