PRESSURE CONTROLS

RV56-26 Relief, Pilot-Operated, High Pressure

DESCRIPTION

A screw-in, cartridge-style, pilot-operated (two-stage), spool-type hydraulic relief

valve, intended for use as a pressure limiting device in demanding hydraulic circuits

which require fast response and low hysteresis.

OPERATION

The RV56-26 blocks ﬂ ow from ➀ to ➁ until sufﬁ cient pressure is present at ➀ to

force the piloting relief off its seat, allowing the main (second stage) spool to shift,

opening

➀ to ➁. The cartridge offers smooth transition in response to load changes in

demanding hydraulic circuits.

NOTE: The RV56-26 cannot be used in cross-over relief applications.

FEATURES

• Adjustments cannot be backed out of the valve.

• Adjustments prohibit springs from going solid.

• Hardened spool and cage for long life.

• Fast, smooth response to pressure surges.

RATINGS

Rated Pressure Range at Crack: 207 to 345 bar (3000 to 5000 psi)

Crack Pressure Deﬁ ned: bar (psi) evident at 7.57 lpm (2.0 gpm) attained.

Reseat Pressure: Nominal 90% of crack pressure.

Flow: See Performance Chart

Internal Leakage: Measured under 85% of pressure setting at 38°C (100°F):

213 ml/minute (13 cu. in./minute).

Spring Range: Model Code 50: 206.8 to 344.7 bar (3000 to 5000 psi)

Operating Temperature: with polyurethane seals: -54°C to 107°C

Filtration: See page 9.010.1

Fluids: Mineral-based or synthetics with lubricating properties at viscosities of

7.4 to 420 cSt (50 to 2000 sus); See Temperature and Oil Viscosity, page 9.060.1

Installation: No restrictions; See page 9.020.1

Cavity: VC16-2; See page 9.116.1

Cavity Tool: CT16-2XX; See page 8.600.1

Seal Kit: SK16-2P-B; See page 8.650.1

USASI/ISO:

SYMBOLS

PERFORMANCE (Cartridge Only)

6.162.1

HYDRAFORCE

.com

414/6000

345/5000

276/4000

207/3000

138/2000

FLOW RATE lpm/gpm

PRESSURE RISE bar/psi

Pressure Rise vs. Flow

32 cSt/150 sus oil at 40nC

151

227

303

379

100

U.S. Patent

7,137,406

Blue rectangles are links to other catalog pages.

DIMENSIONS

MATERIALS

Cartridge: Weight: 0.7 kg. (1.54 lbs.)

Steel with hardened work surfaces.

Zinc-plated exposed surfaces.

Buna N O-rings and polyester

elastomer back-up standard.

Anodized aluminum knobs.

Standard Ported Body: Weight:

0.57 kg. (1.25 lbs.) Anodized high-

strength 6061 T6 aluminum alloy,

rated to 207 bar (3000 psi). Ductile

iron bodies available; dimensions

may differ. See page 8.016.1

TO ORDER

RV56-26__ - __ __ __ - __ - __ __ / __ __ __ __

Seals

P Polyurethane

†

Adjustable valves will be preset to

approx. 50% of spring max. potential.

Spring Range

50 206.8 to 344.7 bar

(3000 to 5000 psi)

Porting

Cartridge Only 0

SAE 12 12T

SAE 16 16T

3/4 in. BSP* 6B

1 in. BSP* 8B

*BSP Body; UK Mfr. Only

Setting in bar

†

(Blank) for Adjustable, or

Specify, for example:

M207 207 bar

M345 345 bar

Setting in psi

†

(Blank) for Adjustable, or

Specify, for example:

30.0 3000 psi

50.0 5000 psi

RV56-26

6.162.2

HYDRAFORCE

.com

Adjustment Option

1/4 in. Hex Allen Head A

1-1/2 in. Dia. Alum. Knob B

Option A w/ Cover Cap C

Factory Preset Non-Adj. F

Factory Preset

Hidden Adjustment H

1.50

38.1

3.52

89.4

1.98

50.3

1.13

28.7

3.00

76.2

1.50

38.1

MAX.

DIA.

ACROSS

FLATS

TORQUE

46–54 ft-lbs

(62.7–73.4 Nm)

1.00

25.4

0.34

8.6

2.56

65.0

0.16

4.1

2.25

57.2

3.00

76.2

3.75

95.2

1.79

45.4

1.79

45.4

2.67

67.8

INCH

MILLIMETRE

U.S. Patent 7,137,406

Blue rectangles are links to other catalog pages.