Duplomatic DS3 Solenoid Directional Control Valve ISO 4401-03

Overview

The Duplomatic DS3 is a direct-operated, solenoid-actuated directional control valve for subplate mounting on the ISO 4401-03 interface, the common size 03 (CETOP 03) pattern used across industrial hydraulics. Duplomatic Motion Solutions, part of the Daikin group, rates the valve for a maximum operating pressure of 350 bar on ports P, A and B and a maximum flow of 100 l/min. It is offered in 3-port and 4-port designs with two or three positions and a wide range of spools, with DC or AC solenoids, which makes the Duplomatic DS3 a general purpose building block for hydraulic power units, machine tools and mobile equipment.

Seven Star LLC supplies the Duplomatic DS3 to hydraulic system builders, OEM service teams and plant maintenance departments in Oman and the GCC, with engineering support in Muscat. Because the full identification code fixes spool, voltage, connector, override and options, our engineers in Muscat decode the code from the nameplate of an existing valve or from a circuit drawing before supply, so the replacement fits the same subplate and behaves the same way in the circuit.

Operating Principle

In the Duplomatic DS3, a spool slides inside a bore in the valve body and connects the pressure port P, the tank port T and the work ports A and B in different combinations. Wet armature solenoids, with the armature running immersed in oil inside a tube threaded into the body, push the spool directly against centring or return springs, so no pilot stage is needed. The inner part of the tube is in contact with return line oil, which carries heat away from the solenoid and allows a 100% duty cycle.

The spool symbol determines circuit behaviour. Type S* has two solenoids and three positions with spring centring; SA* and SB* have one solenoid and two positions (centre plus one end) with spring centring; RSA* and RSB* return to the end position by spring; TA and TB are single-solenoid, two external positions with return spring; and RK has two solenoids, two positions and mechanical detent. Duplomatic lists switching times measured to ISO 6403 at 36 cSt and 50 °C of 25 to 75 ms on energizing and 15 to 25 ms on de-energizing for DC, and 10 to 25 ms and 15 to 40 ms for AC.

Engineering Design of the Duplomatic DS3

The body of the Duplomatic DS3 is made from high-strength iron castings with wide internal passages to minimise pressure drop. The standard body finish is black phosphating; a zinc-nickel finish (option /W7, DC only) gives up to 240 hours of salt spray resistance with standard coils, and up to 600 hours when combined with corrosion-protected W or ULW coils and a C* type manual override, tested to UNI EN ISO 9227. Coils are interchangeable, can be rotated through 360° and are fastened by a threaded locking ring tightened to 5 ±0.5 Nm. The valve is fixed to the subplate with screws in M5x10 threaded holes at a tightening torque of 5 Nm (class 8.8).

Electrical options are extensive. DC coils run from 12 to 220 V with about 29 to 35 W consumption, for example 31 W for the standard D24 coil; AC coils cover 24 to 240 V at 50 or 60 Hz, with the A230 coil drawing 213 VA inrush and 48 VA holding at 230 V 50 Hz. Connections include K1 for EN 175301-803 (ex DIN 43650) connectors, K2 for AMP Junior, and K7 or K7D Deutsch DT04-2P plugs, the latter with a suppression diode. UL Recognized ULW coils are available for the North American market. With K1 the valve reaches IP65, while W or ULW coils with Deutsch plugs and a C* override achieve IP66/IP68/IP69 and IP69K.

Key Features

The main features of the Duplomatic DS3 according to the manufacturer catalogue are:

• ISO 4401-03-02-0-05 (CETOP 4.2-4-03-350) mounting surface for direct interchange on standard size 03 subplates and manifolds.
• Maximum pressure of 350 bar on P, A and B, with T port limits of 210 bar on DC and 160 bar on AC versions.
• Flow up to 100 l/min with low pressure drop through wide cast passages.
• More than twenty spool configurations, including regenerative and detented versions.
• DC, AC and rectified-AC operation, plus a soft-shifting DC version for smoother actuator movement.
• Manual override choices including integrated pin, boot protected, lever, push button, knob, push-and-twist and detent types.
• NBR seals for mineral oil or FPM seals for phosphate ester (HFDR) fluids.
• Optional DS3R version with fixing interchangeable with Rexroth 4WE6*6X valves.

Industrial Applications

In Oman, the Duplomatic DS3 is found on hydraulic power units that drive clamping, lifting and indexing cylinders in fabrication shops, on press and injection moulding machinery, on test benches, and on hydraulic systems for gates, dampers and bridges at utilities. Its 350 bar rating and compact size also suit hydraulic control panels on wellhead and valve actuation packages in the oil and gas sector, and the zinc-nickel and IP69K options help the Duplomatic DS3 survive outdoor and coastal sites in the Sohar and Duqm areas.

Seven Star LLC supplies the Duplomatic DS3 together with subplates such as PMMD-AI3G (rear ports) and PMMD-AL3G (side ports), both with 3/8 inch BSP threads, and spare coils and seal kits. For related hydraulic actuation we also supply the Magnet-Schultz FHMG and FHTS hydraulic solenoids, the Rotork Skilmatic SI3 electro-hydraulic actuator and the Masoneilan 84/85/86 cylinder actuators with hydraulic manual override, giving maintenance teams one source for hydraulic control components.

Technical Specifications

The Duplomatic DS3 data below are taken from Duplomatic catalogue 41 150/426 ED (values with mineral oil at 36 cSt and 50 °C):

How to Order

For the Duplomatic DS3, send Seven Star LLC a formal RFQ with the complete identification code or the spool symbol, voltage, connector and override required, and our instrumentation division will confirm the configuration and quote supply on request. The Duplomatic DS3 catalogue is attached on this page as a technical datasheet download. Seven Star LLC supplies Duplomatic hydraulic valves to industrial and energy customers throughout Oman and the GCC, with engineering support in Muscat.