VR4R series
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PILOT OPERATED PRESSURE REDUCER VALVE - Series VR4R Veljan Pressure Reducer Valve Series VR4R are pilot operated controls used to control pressure in a secondary part of a hydraulic circuit. Pressure is maintained as set by control knob on the pilot or by an external pilot source. In some application,VR4R is used to maintain a lower pressure in the secondary circuit to limit the force available from certain actuators. VR4R consists of a high flow poppet type seat valve section controlled by the low flow, adjustable pilot section mounted on top. Pressure setting is achieved by means of a knurled knob. For tamper proof setting, acorn nut with lead seal is available as an option. Optional vent valve VVVO1 sandwiched between pilot section and main body can be used for venting the VR4R valves. Extremely accurate settings can be obtained due to the precise construction of control components. The design of poppet allows for the minimum of friction and hysteresis giving a sensitive response to conditional changes. Normally, port A is connected to the secondary part of the hydraulic circuit and port B to the primary part. When the secondary port A is unpressurised, the main poppet opens X1 downwards against a spring by the pressure at primary Port B. Flow passes from primary port B to secondary port A. Pressure at port B passes to the pilot section and to the top of main poppet through an orifice. No flow takes place in this section until the pressure demand exceeds the setting of the pilot head ,as determined/set by the control knob. The pilot cone lifts from its seat against the setting spring and allows a maintained pilot flow to pass to external drain. The effect of this is to limit the pressure available on top of the main poppet. In this condition the main poppet moves up and floats allowing enough flow to the secondary circuit ( port A) to maintain the set pressure. If the secondary circuit exceeds the pilot head setting, the main poppet moves up further and Y closes preventing flow to a secondary circuit. Possibilities of any pressure intensification in the secondary part is eliminated by the small check valve when it opens and allows flow to pilot drain.

PILOT OPERATED PRESSURE REDUCER VALVE - Series VR4R SPECIFICATIONS General Type Design Mounting Mounting position Port sizes (nominal) Direction of flow Ambient temperature Special working conditions Pilot operated Pressure reducer Valve Poppet type Threaded/Subplate/Cartridge Optional 3/8”, 3/4”, 1 1/4” B A --20° C...+60° C (--4° F...+140° F) Consult VELJAN Hydraulics Pressure control range Minimum - depends on flow Maximum - 5000 psi (350 bar) Maximum operating pressure Port B ( primary ) Port A ( secondary ) Port X (pilot) Port Y, Y1 (Pilot drain ) 5000 psi (350 bar) Without pressure to...

PILOT OPERATED PRESSURE REDUCER VALVE - Series VR4R ORDERING CODE VR4R 06 Modification Series Seal Class Size 03 06 10 1 - Buna N ( Standard) 5 - Viton Design letter Max. Pressure of Valve Body Solenoid Voltage (Omit for non vent version) Body Mounting Cartridge 0 - Cartridge X1 + Y1 port = E - Cartridge X1 + Y1 port = SAE - 4 / G - Cartridge X1 + Y1 port = G 14” Threaded body /” 1 - Threaded body - VR4R03 = 12 NPTF ; X1,Y1ports ( 2 A - Ports, 1B - Port ) 1 ” = / 4 / A - Threaded body VR4R06 = 34” NPTF ( 1 A - Port, 1B - Port ) / 6 - Threaded body VR4R03 = 12” B.S.P.P ; X1,Y1ports ( 2 A -...

PILOT OPERATED PRESSURE REDUCER VALVE - Series VR4R PERFORMANCE CURVES ps min - qv characteristics VR4R03 Minimum Differential Pressure between Inlet & Outlet Pressure at Various Flow Rates 350 (5075) The effect of increase of Inlet Pressure on Outlet Pressure setting Variation in Outlet Pressure for variation in Flow Rate The effect of increase of Inlet Pressure on Outlet Pressure setting Variation in Outlet Pressure for variation in Flow Rate Minimum Differential Pressure between Inlet & Outlet Pressure at Various flow Rates Note : All Performance Data given is typical and can be...

PILOT OPERATED PRESSURE REDUCER VALVE - Series VR4R VR4R06 (3/4”) SUBPLATE MOUNTING BODY ( #3, #7 & #9 ) Weight : 9.89 lbs (4.5 kg) Panel opening Block mounting face Flatness 0.01 mm/100 mm length Surface finish CLA 1.27 µm Location hole Primary (inlet) Secondary (outlet) Remote control or vent connection External drain Note : For details of Subplate & mtg. screws p

PILOT OPERATED PRESSURE REDUCER VALVE - Series VR4R SUBPLATE FOR VR4R06 (3/4”) Location hole 3/8” - 16 UNC x 0.709 dp (M10 x 18 dp). Note: Not used,must be plugged before installation (1/4”NPTF or G1/4”) Port sizes Order No. min.tensile strength * Mounting screws are included in subplate order. For valves ordered without subplate mounting screws must be ordered seperately.

PILOT OPERATED PRESSURE REDUCER VALVE - Series VR4R VR4R06 (3/4”) - THREADED BODY ( #A, #B & #D ) Ports sizes Primary (inlet) Secondary (outlet) Remote control External drain

PILOT OPERATED PRESSURE REDUCER VALVE - Series VR4R CARTRIDGES WITH PILOT VALVES VR4R06/VR4R10 ( #0, #E & #G ) Weight : 2.64 lbs (1.2 kg) (1/4” NPTF or G1/4" or SAE-4) Primary (Inlet) Secondary (Outlet) Internal pilot pressure Remote control or vent connection External drain 4 Mounting screws* Order - No.