VDP08
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VDP08 Load-Sense Proportional Pressure Compensated Valve SECTION A - Technical Catalogue

LOAD-SENSE PROPORTIONAL PRESSURE COMPENSATED VALVE

LOAD-SENSE PROPORTIONAL PRESSURE COMPENSATED VALVE GENERAL INDEX

LOAD-SENSE PROPORTIONAL PRESSURE COMPENSATED VALVE GENERAL INDEX E0.241.0613.02.00IM06 The data on this catalogue refer to the standard product. The policy of Salami consists of a continuos improvement of its products. It reserves the right to change the specications of the different products whenever necessary and without giving any information. If any doubts, please get in touch with our sales department.

DIRECTIONAL CONTROL VALVE PRESSURE COMPENSATED FEATURES OPERATING PRINCIPLE Load sensing directional control valve VDP08 offers a load-independent ow control (ow in each section depends only by the spool position and not by the load acting on any function), good meetering curves and chance of energy saving. The spool acts as a variable throttling on which the pressure drop is maintained constant, so that each spool position arouses a determinate ow rate. Closed centre version for variable displacement pumps The valve, through the LS signal, sets the pump displacement on the value required...

HYDRAULIC FLUID Mineral oil according DIN 51524 Fluid temperature range - 20 + + 85°C MAXIMUM CONTAMINATION LEVEL NAS 1638: class 9 WORKING LIMITS See diagrams PRESSURE DROPS See diagrams For operation with fire resistant fluids, please contact our sales department. There are two characteristic phases in the spool stroke (7 mm - 0,275 in.): a) the overlap phase (about 18% of the stroke) guarantees minimum internal leakages in neutral position; b) the progressive flow regulation phase (82% of the stroke). Oil flow rate portP uptol301/min (34 gpm) Internal leakage at 160 bar (2285 psi) ports...

DIRECTIONAL CONTROL VALVE PRESSURE COMPENSATED FEATURES VALVE AND DEVICE TYPES In order to meet the most stringent demands and to offer a wider range of applications, the following types of auxiliary valves and devices are available: · Valves on the inlet Main relief valve - VSLS (see page 7A): controls the maximum pressure in the circuit acting on the LS signal that pilots the ow regulator. Electric unloading valve - EV (see page 9A): if not excited drains the LS signal preventing the valve operation (pump pressure set at the stand-by value 14 bar - 200 psi). Flow regulator (see page 7A):...

DIRECTIONAL CONTROL VALVE PRESSURE COMPENSATED FEATURES INSTALLATION When proceeding to mount the unit on the structure and to connect ttings to work ports, it is necessary to comply with the values of tightening torques (see page 18A). The attachment of linkages to spools should not affect their operation. The mounting position can be vertical with inlet module on the top or horizontal. We recommend to x the valve always using only 3 of the 4 xing holes, otherwise make sure to interpose 4 rubber insulators between the valve and the machine frame, to avoid valve distorsion and spool...

DIRECTIONAL CONTROL VALVE PRESSURE COMPENSATED FEATURES HYDRAULIC FLUID Usually a mineral-base oil with a good viscosity index should be used, preferably with good lubricating properties and corrosion, oxidation and foaming resistant. Sometimes the uids supplied by the manufacturers do not satisfy purity requirements (see WORKING CONDITIONS). It is therefore necessary to lter the uid carefully before lling. Your supplier can give you the information about NAS class of its uids. To maintain the proper purity class, the use of lters of high dirt capacity with clogging indicator is...

DIRECTIONAL CONTROL VALVE PRESSURE COMPENSATED DIMENSIONS A/B: working ports P: top inlet port PL:side inlet port T: top outlet port TL:side outlet port LS (see page 8A): load-sensing signal port PG (see page 8A): pressure gauge port The drawing showned is just an example.The overall dimensions you read are valid for all the D.C.V. except the parametric dimensions "L" and "I" depending on the number of working sections.The parametric dimensions "P" depends on a xed dimension of 127 mm (5 in.) to wich you have to had the "X" dimensions that you can nd in the following pages. L I Fixing holes...

DIRECTIONAL CONTROL VALVE PRESSURE COMPENSATED INLET/OUTLET MODULES OPERATING PRINCIPLES OPEN CENTRE CIRCUIT WITH FIXED DISPLACEMENT PUMP “CODE F” - SEE PAGE 8A When the pump is started and main spools in the working modules are in neutral position, oil ows from the pump through P port across the ow regulator to tank T . The oil ow led across the ow regulator determines the pump pressure(stand-by pressure of 14 bar - 200 psi). When one or more of the main spools are actuated, the highest load pressure is fed through the shuttle valve circuit("LS" pilot gallery, see hydraulic circuit at...

DIRECTIONAL CONTROL VALVE PRESSURE COMPENSATED INLET/OUTLET MODULES Hydraulic circuit Hydraulic circuit code F Open centre for fixed displacement pumps Closed centre for variable displacement pumps PRESSURE COMPENSATOR PRESSURE GALLERY TANK GALLERY PRESSURE RELIEVE VALVE

DIRECTIONAL CONTROL VALVE PRESSURE COMPENSATED INLET/OUTLET MODULES Inlet module circuit with LS electrical unloading valve - “ EV “ normally open Hydraulic circuit normally closed Electrical unloading valve “EV” NC CIRCUIT DESCRIPTION: “EV” is an unloading electrovalve of the “LS” signal. ”EV” is tted into the inlet module enabling a connection between the “LS” and the tank lines. The “LS” signal can be relieved to tank switching the electrovalve by an electrical signal. “EV” VALVE IN THE OPEN CENTRE CIRCUIT “CODE F” For an open centre inlet module the relief to tank of the “LS” signal...

DIRECTIONAL CONTROL VALVE PRESSURE COMPENSATED INLET/OUTLET MODULES Inlet module for parallel connected valves code X Before to order this code, please get in touch with our sales dept. The “X” module allows to realize a parallel connection of two d.c.v. as showned on the side.The “X” module Instead to be equiped with a ow regulator it is just plugged in. The hydraulic circuit shows the upstream d.c.v. with “F” inlet module ( for xed displacement pump) and the downstream valve with the “X” inlet module.The downstream d.c.v. takes the “LS” signal from the end module of the upstream d.c.v....