Danfoss Electronics NRVA Catalog Page

Shut-off and regulating valves

Check valves

for Industrial Refrigeration

Type NRVA

Check valve type NRVA can be used in liquid,
suction and hot gas lines in refrigeration and air
conditioning plant with ammonia.

NRVA can also be used in refrigerating systems
with fluorinated refrigerants.

When the NRVA is used in liquid lines where
cold, thick oil or impurities may be present, it
is recommended that the standard spring be
replaced by a special spring. See ordering table.

Features • Ensures correct direction of flow.

• Valve housing made of steel.

• Available for 40 bar g / 580 psig working
pressure.

• Large range of flanges with connection
dimensions in accordance with standards: DIN,
ANSI, SOC, SA and FPT.

Design

Connections

There is a very wide range of connection
possibilities with NRVA check valves:

• Welding, DIN (2448)

• Welding, ANSI (B 36.10)

• Welding socket, ANSI (B 16.11)

• Solder connection, DIN (2856)

• Solder connection, ANSI (B 16.22)

• FPT internal thread, NPT
(ANSI/ASME B 1.20.1)

• Fitted with damping piston that makes the
valves suitable for installation in lines where
pulsation can occur, e.g. in the discharge line
from the compressor.

• Classification: DNV, CRN, BV, EAC etc.
To get an updated list of certification on the
products please contact your local Danfoss
Sales Company.

Gaskets:

Do not contain asbestos.

Valve cone:

The valve cone has a teflon tightening ring.
Teflon tightening ring renders perfect sealing at a
minimum closing force.

© Danfoss | DCS (mwa) | 2018.11

AF251686497757en-001012 | 43

Check valves, type NRVA

Technical data • Refrigerants

Applicable to HCFC, HFC and R717 (Ammonia).
For further information please see installation

• Pressure range
The valve is designed for:
Max. working pressure: 40 bar g / 580 psig.

instruction for NRVA.
Use with flammable hydrocarbons cannot be
recommended; please contact Danfoss.

• Temperature range

-50 – 140 °C / -58 – 284 °F.

Material specification

Material specification for NRVA check valves

No. Part Material DIN ISO ASTM

1 Housing Steel G20Mn5QT *)

2 Flanges Steel RSt. 37-2, 10025 Fe360 B, 630 Grade C, A 283

3 Valve cone Stainless steel

Teflon

5 Spring Steel

9 Bolts Stainless steel A2-70

10 Nut Stainless steel

11 Gasket Non asbestos

12 Valve seat Steel

*) NRVA 40 / NRVA 50 housing material is TTSt 35N until January 2006

EN10213-3

--------------------------------------­P285QH
EN10222-4

LCC, A352

--------------------------------------­LF2,A350

Ordering

44 | AF251686497757en-001012

Complete valves incl. DIN 2448 flange:

Weld flange

Type

NRVA 15

NRVA 20

NRVA 25 1 020-2002 020-2317 0.12 1.7 0.3 4.4 19 22

NRVA 32 1 1⁄4 020-2003 020-2317 0.12 1.7 0.3 4.4 20 23

NRVA 40 1 1⁄2 020-2004 020-2327 0.07 1.0 0.4 5.8 44 51

NRVA 50 2 020-2005 020-2327 0.07 1.0 0.4 5.8 44 51

NRVA 65 2 1⁄2 020-2006 020-2337 0.07 1.0 0.4 5.8 75 87

1

) A special type spring can be supplied to replace the standard valve spring.

2

) Dp = the minimum pressure differential at which the valve is completely open.

3

) The kv value is the flow of water in m3/h at a pressure drop across valve of 1 bar, ρ = 1000 kg/m3.

4

) The Cv value is the flow of water in gal/min at a pressure drop across valve of 1 psig, ρ = 10 lbs/gal.

connection

[in] [bar[ [psig] [bar] [psig] [m3/h] [gal/min]

1

⁄2 020-2000 020-2307 0.12 1.7 0.3 4.4 5 6

3

⁄4 020-2001 020-2307 0.12 1.7 0.3 4.4 6 7

Valve body without flanges:

Type Code no.

NRVA 15 020-2020

NRVA 20 020-2020

NRVA 25 020-2022

NRVA 32 020-2022

NRVA 40 020-2024

NRVA 50 020-2024

NRVA 65 020-2026

Code no. Dp 2)

Valve Spec. spring 1)

standard spring

Staybolts and gaskets

Type Dimensions Code no.

NRVA 15 / 20 M 12 × 115 mm 006-1107

NRVA 25 / 32 M 12 × 148 mm 006-1135

NRVA 40 / 50 M 12 × 167 mm 006-1137

NRVA 65 M 16 × 200 mm 006-1138

With

With

spec. spring 1)

kv value 3) Cv value 4)

© Danfoss | DCS (mwa) | 2018.11