Moog D926 and D927 Direct Operated Proportional Valve, ISO 4401 Size 03/05

Overview

The Moog D926 and the larger D927 make up the Moog D92x series of direct operated proportional valves with integrated electronics. In contrast to Moog servo-proportional designs with a bushing, these valves use a spool running directly in the valve body, moved by two proportional solenoids, one for each direction. The spool-in-body construction allows a large spool diameter and long stroke, giving high rated flows from a compact valve. On the ISO 4401 size 03 interface the Moog D926 provides rated flows of 4, 8, 16 or 32 l/min and a maximum flow of 80 l/min; the D927 fits size 05 with 25, 50 or 75 l/min and a maximum flow of 180 l/min. Both are rated for 350 bar on ports P, A and B.

Seven Star LLC supplies the Moog D926 and D927, their mating connectors, seal kits and mounting bolts to hydraulic OEMs, service companies and plant engineers across Oman and the wider GCC, with engineering support in Muscat when choosing flow size, spool overlap, flow characteristic and signal code from the Moog ordering information.

Operating Principle

Inside the Moog D926, spool position is regulated electronically: an LVDT transducer reports where the spool is, and the onboard electronics act on that reading. A spool position set point arrives at the main connector, the LVDT measures the actual position, and the circuit energises whichever proportional solenoid is needed with a PWM current to move and hold the spool where it is commanded. Spool position is therefore proportional to the electric command, independently of flow forces and supply variations. When electrical power is removed, two springs centre the spool, which defines the de-energised position of the valve.

A key strength of the Moog D926 is configurability. Moog offers spools with 1.5 to 3% positive overlap for closed-loop servo-like applications, 15% or 10% positive overlap for open-loop applications where tight centre sealing is preferred, and variants with underlap from A and B to T, together with linear or progressive flow characteristics. A 4/2-way version with a single solenoid and LVDT on the A side is also listed. Moog notes that for spools with 1.5 to 3% overlap the spring-centred position may not correspond exactly with the hydraulic zero position, which should be considered in safety design.

Engineering Design of the Moog D926

Built as a single-stage unit, the Moog D926 has a mass of 3.5 kg and bolts onto an ISO 4401-03-03-0-05 subplate, where the leakage port Y is optional; Moog permits any installation orientation. Its bigger counterpart, the D927, sits on an ISO 4401-05-05-0-05 interface with no Y port and weighs 8 kg in 4/3-way form or 6.6 kg in 4/2-way form. Moog mounts the electronics directly above one of the two solenoids and isolates the circuit board mechanically from its housing. This arrangement lets the D926 withstand 30 g vibration (the D927 is rated 20 g) across 10 Hz to 2 kHz in all three axes, plus 50 g shocks. For functional safety calculations Moog quotes an MTTFd of 150 years under EN ISO 13849-1.

The valves run on 24 V DC with a maximum current of 1.4 A (33.6 W) for the Moog D926 and 3 A (72 W) for the D927. Electrical connection is a 6-pole plus PE connector to EN 175201-804. Command signal codes include ±10 V, ±10 mA and 4 to 20 mA, with the actual spool position available as ±10 V or 4 to 20 mA for monitoring and fault detection. Degree of protection is IP65 with the mating connector fitted. Seal material options include FKM and HNBR, and the maximum T port pressure is 280 bar for the D926 and 250 bar for the D927.

Key Features

Key features of the Moog D926 and D927 from the Moog D92x catalog are:

• Direct operated proportional valve with two proportional solenoids and spool-in-body design.
• Closed-loop spool position control by LVDT and integrated digital-core electronics.
• ISO 4401 size 03 (D926) and size 05 (D927) mounting patterns.
• Rated flows of 4 to 32 l/min (D926) and 25 to 75 l/min (D927) at 5 bar per spool land.
• Maximum operating pressure of 350 bar on ports P, A and B.
• Step response of 18 ms (D926) and below 28 ms (D927) for 0 to 100% stroke.
• Wide choice of spool overlaps and linear or progressive flow characteristics.
• Electronics decoupled from the housing for high vibration resistance and long service life.

Industrial Applications

Moog describes the D92x series as suitable for electrohydraulic control of position, speed, pressure and force in open-loop and closed-loop systems. Typical uses of the Moog D926 include positioning cylinders on presses, bending and forming machines, speed control of hydraulic motors on conveyors and winches, clamping and injection axes on plastics machinery, and pressure or force control on test rigs. The higher flow D927 serves larger cylinders and motors where a size 05 valve is required. The open-loop overlap options make the Moog D926 suitable for machines without external position feedback.

In Oman and the GCC the Moog D926 is relevant for metal processing and fabrication workshops, steel and aluminium plants in Sohar, oil and gas equipment such as pipe handling, wellhead control and hydraulic power units, port and marine machinery, and municipal and industrial test benches. The robust design and wide ambient range of −20 to +60 °C suit hot plant environments. Seven Star LLC supplies the Moog D926 and D927 for new machines and as like-for-like replacements, and can advise on Moog cleanliness recommendations for the hydraulic fluid.

Technical Specifications

The Moog D926 and D927 data below are taken from the Moog D92x series catalog, Rev. D, February 2026.

How to Order

To order a Moog D926 or D927, send Seven Star LLC the full Moog part number from the valve label, or your required size, rated flow, spool overlap and characteristic, seal material and signal code, and we will prepare a formal quotation. The Moog D92x catalog is available as a download on this page. Seven Star LLC supplies Moog hydraulic valves in Oman and the GCC with engineering support in Muscat. Related products include the MOOG G761 Electrohydraulic Servo Valve, the Moog D791 Pilot-Operated Servo Valve and the Moog 79 Series Flow Control Servo Valve.