• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Skip to footer

Mobile Hydraulic Tips

Mobile Hydraulic Tips focuses on pumps, fittings, valves, manifolds and other products and news in the Mobile Hydraulics industry.

  • Hydraulics Blog
  • Industry News
  • Engineering Basics
  • Components
    • Cylinders
    • Fittings / Couplings
    • Pumps / Motors
    • Sensors / Gauges
    • Valves / Manifolds
    • Related components
  • Design Guide Library
  • Advertise
  • Subscribe

What type of flow divider is best for my application?

June 9, 2022 By Mary Gannon

Share

By Josh Cosford, Contributing Editor

Flow dividers provide a unique solution to a specific problem in hydraulic applications — splitting flow while limiting its tendency to take the path of least resistance. Without a flow divider, any time you wish to split flow to two or more downstream subcircuits, the path with the lowest pressure will steal most (if not all) of the flow. Common designs include spool or gear type flow dividers that input a single flow path and output two or more at a given ratio. Other designs include radial piston and volumetric types.

webtec high-flow divider-combiner valve FDC140 Hi
Webtec’s high-flow divider combiner valve

Spool-type flow dividers use a Y-shaped ported body and a clever method of pushing the spool toward the outlet port with the lowest pressure. This form of pressure compensation will choke the flow on the side, attempting to take the path of least resistance, thereby equalizing the pressure drop through each of the outlet ports. However, the method is not entirely accurate, allowing up to 15% or more of the flow to take the low-pressure path.

Spool flow dividers are particular in their operation, requiring they are specified for their ideal pressure and flow range. Should you operate with flow less than their specified minimum, they become unstable and imprecise. Conversely, with too much flow or too much differential pressure, the flow divider may lock up one flow path only.

Because flow dividers do not offer absolute accuracy, you can expect hydraulic cylinders to drift out of synchronization, primarily when they’re not provided with the opportunity to reach the end of stroke. Spool flow dividers may use a pressure compensated orifice to divert flow from a stalled cylinder to the active one, allowing for synchronization. Should your flow divider come with no inherent synchronization capability, cross port relief valves installed on the two work ports offers the same effect.

Jahns MTO small gear flow dividers with integrated relief valves. Image courtesy of IC Fluid Power
Jahns MTO small gear flow dividers with integrated relief valves. Image courtesy of IC Fluid Power

Flow dividers aren’t limited to 50:50 flow division, and with spool-type, you may find ratios such as 60:40 or 33:66. Custom ratios would be available for high volume OEMs, but the most common ratio is still 50:50. Motors benefit from unequal flow split, allowing two motors of the same displacement to rotate at the different RPM, or perhaps two motors of different displacement to rotate at the same speed.

Gear type flow dividers are essentially hydraulic pump/motors connected by a common shaft. That single shaft ensures each gear section rotates at the same speed, thereby each flowing equally. Gear-type flow dividers tend to be more efficient than spool-type flow dividers. Less fluid is lost from one outlet port to the other, whereas with spool-type flow dividers, the clearances are larger to allow for lubrication of the spool.

Gear type flow dividers come with up to eight sections or sometimes more, which is an advantage over spool-type, which primarily offer just two outlet ports. However, for gear-type flow dividers to synchronize, you must install relief valves at each outlet port to send the fluid back to the flow divider inlet from a stalled actuator.

5-Jahns-MZB-Volume-Divider
Multi chamber MZB flow divider from Jahns is designed for high-precision applications. This divider is primarily used in 2 to 4 chambers; however, these can be built with up to 12 chambers and is available in many sizes. The MZB also gives the advantage of a low pressure drop.

Most flow dividers are also combiners, meaning they will accept flow in retraction and extension, for example. In combining mode, synchronization still occurs and helps to keep multiple actuators in synch for both directions at the end of stroke. Gear flow dividers are inherently combiners, but spool-type dividers must be specified as such.

Two additional styles, radial piston type and volumetric dividers, offer high synchronization. Radial piston types divide a single flow into two output flows offer high volumetric efficiency and low speed capability. Volumetric dividers work only by volume dosage and the exchange between volume synchronizer and working cylinders. These are best suited for high-precision applications that require low pressure drop.

 

 

You may also like:

  • webtec high-flow divider-combiner valve FDC140 Hi
    High-flow divider-combiner valve for heavy-duty applications

  • What is a flow divider?
  • Webtec-CV120_2 hydraulic control valve
    Hydraulic combination valve offers complete motor control for mobile machinery
  • Webtec VFD120_E base priority flow divider
    Electric-operated variable-priority flow divider offers higher efficiency

  • Bucher flow dividers offer higher precision

Filed Under: Components, Engineering Basics, Featured, Valves / Manifolds

Primary Sidebar

Fluid Power Design Guides

fluid
“mht
EXPAND YOUR KNOWLEDGE AND STAY CONNECTED
Get the latest info on technologies, tools and strategies for Fluid Power Professionals.

Fluid Power World Digital Editions

Fluid Power World is written by engineers for engineers engaged in designing machines and or equipment in Off-Highway, Oil & Gas, Mining, Packaging, Industrial Applications, Agriculture, Construction, Forestry, Medical and Material Handling. Fluid Power World covers pneumatics, mobile hydraulics and industrial hydraulics.

Footer

Mobile Hydraulic Tips

FLUID POWER WORLD NETWORK

  • Fluid Power World
  • Hose Assembly Tips
  • Pneumatic Tips
  • Sealing and Contamination Tips
  • Fluid Power Distributor Lookup

MOBILE HYDRAULIC TIPS

  • Subscribe to our newsletter
  • Advertise with us
  • Contact us
  • About us

Copyright © 2025 · WTWH Media LLC and its licensors. All rights reserved.
The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media.

Privacy Policy