A hydraulic manifold is not only installed, it carries flow — what stays in the channel stays in the system.
Cleaning and deburring hydraulic manifolds
1 · The challenge
Why hydraulic manifolds are difficult to clean and to deburr
A hydraulic manifold is at its core a block of material with a channel system inside. The channels are drilled, they intersect several times, and at every bore intersection a burr forms. No mechanical tool reaches any of these places.
At the bore intersection of two bores sits the burr root of the hydraulic manifold. No tool gets there — not because it would be too big, but because no path leads to it.
And on the hydraulic manifold, the burr is not the end of the story. It comes loose later and travels with the process medium through the component, into hydraulic and oil channels, to valves, into pumps. A detached burr in the channel is not a form deviation, but residual contamination — and thus the same question that every parts cleaning system has to answer as well.
The same geometry makes cleaning the hydraulic manifold difficult. Blind holes and branched channels are exactly the places a spray jet does not reach: it hits what it sees. What it does not see stays untreated — and becomes visible in the residual contamination verification.
Added to this on the hydraulic manifold are the sealing faces, whose cleanliness only becomes apparent in the downstream process — in adhesive bonding, coating or sealing.
2 · Engineering considerations
What we base the system design on
- 01
Part geometry
Hydraulic manifolds are predominantly made of aluminum and aluminum die casting — not as a property of the method, but because modern manifolds and housings are manufactured that way. Steel, stainless steel, brass, copper, zinc die casting and plastic we process just as well. There is no limit at the material: what is decisive are part geometry, burr root, accessibility and process objective. - 02
Internal geometry
On the hydraulic manifold, blind holes, through-holes and internal channels with cross-drilled holes decide the method: spraying creates a spray shadow, not every surface can be reached. Many bores additionally speak for lance technology — targeted instead of across the whole surface. - 03
Workpiece fixture
On the hydraulic manifold, the parts carrier is not an accessory but an essential part of the system concept: its design engineering helps determine where spray shadow arises and whether the nozzles reach the component. In deburring, a jet works against the component — the clamping fixture has to absorb this force and at the same time leave every deburring location freely accessible. That is why it is a design component of the process. - 04
Residual contamination requirement
What has to be verified on the hydraulic manifold stands at the beginning of the system design, not at its end: the required residual contamination values act on the method, the filtration, the drying and the workpiece fixture at the same time. Added to this is a second reference — the function of the finished component. A hydraulic manifold is not only installed, it carries flow. - 05
Deburring requirement
Whether the hydraulic manifold additionally has to be deburred is decided in the same technical clarification: where a burr is involved as well, water jet deburring is usually the better solution. The burr root at the bore intersection of two bores lies where no tool reaches mechanically. - 06
Production volume
Deburring by hand works on the hydraulic manifold as long as the production volume is small and nobody demands a verification. As soon as one of the two tips, quality hangs on the form of the day and the cycle on the number of hands. - 07
Cycle time
It is the order of magnitude that decides, not the number of seconds: if several minutes per cycle are permissible on the hydraulic manifold, the chamber cleaning system comes into question; if the cycle is measured in seconds and the system stands in a line, it is continuous or rotary indexing cleaning systems. - 08
Downstream process
Whether the hydraulic manifold is adhesively bonded, coated or painted after cleaning changes the requirement fundamentally — right down to the question of which water quality is needed. That is exactly where the cleanliness of the sealing faces becomes apparent: only in the downstream process.
3 · The system concepts
Which system concepts and methods come into question
Water jet deburring
If the burr root on the hydraulic manifold sits at the bore intersection of two bores, water jet deburring comes into question: the water jet needs no path for a tool, only one for the process medium.
Robot cell with a single robot
If the range of parts changes and hydraulic manifolds run in small to medium production runs, the single-robot cell can make sense — it brings the nozzle to every deburring location, including cross-drilled holes and internal channels.
Robot cell with two robots
If a hydraulic manifold has many distributed deburring locations and their sum exceeds the required cycle, the dual-robot cell comes into question in particular: the more locations, the better the work can be divided.
Stationary deburring system
If the hydraulic manifold runs in a constant version with always the same deburring locations, a fixed clamping position with fixed nozzle systems can be enough — then the stationary deburring machine is more cost-effective than robotics, and we tell you so.
Chamber cleaning systems
ZKFor hydraulic manifolds, the chamber cleaning system can make sense when a changing range of parts runs and several process steps are to take place in one closed chamber.
Continuous cleaning systems
ZDIf the cycle on the hydraulic manifold is measured in seconds and the system stands in a line, the continuous cleaning system comes into question: successive zones instead of one chamber, designed for a continuous flow.
Rotary indexing cleaning systems
RTIf the cleaning process on the hydraulic manifold is fast enough and the time is lost in loading and unloading, the rotary indexing cleaning system can make sense: loading and unloading run parallel to processing, the auxiliary time drops out of the cycle. It presupposes a defined production process with a constant process sequence.
Immersion cleaning systems
ZTWhere spraying fails at the spray shadow on the hydraulic manifold, immersion can lead to the result: the workpiece is brought completely into the process medium so that it reliably reaches all areas.
Lance technology
If a hydraulic manifold has many bores and through-holes, lance technology can be added: the process medium is guided into the individual bore in a targeted way instead of across the component. The lance arrangement is designed for the specific component — if the component changes, the arrangement changes.
The principle
Why several solutions are possible for the hydraulic manifold
None of these assignments is a rule. A valve block or hydraulic manifold is at its core the same case: a block of material with a channel system inside — manifolds, housings and valves follow the same geometry and cleanliness logic. That is why on the hydraulic manifold, too, it is not the name of the component that decides, but the interplay of part geometry, production volume, cycle time, residual contamination requirement and material flow. There is no rule “component X, machine Y” — what you see here is the consideration, not its result.
4 · What else to consider
What else has to be clarified for the hydraulic manifold beyond cleaning and deburring
- 01
It is two verifications, not one
The hydraulic manifold is inspected twice: residual burr — is the burr gone? — and residual contamination — is the part clean? Both verifications run through one contact person, but not both through the same hands: the residual contamination analysis is carried out by an independent, accredited test laboratory, not by us. - 02
The water jet removes the burr, it does not shape the edge
Tight tolerance positions on the sealing faces of the hydraulic manifold are at the same time a limit: the burr may be removed, the edge must not be changed. Where a defined chamfer or radius is required, another method is the right one. We say so before the quotation, not at acceptance. - 03
At the beginning stands the geometry, not the machine
A jet that misses the bore intersection in the hydraulic manifold by a few degrees does not remove the burr. What is decisive is the alignment — and that is why we need 3D data before a machine concept is discussed. - 04
Deburring and cleaning are considered together
A burr in the channel of the hydraulic manifold is not a form deviation, it is residual contamination as soon as it comes loose. That is why it is considered together whether deburring and cleaning take place — and whether both are possible in one step.
Questions and answers
Frequently asked questions about the hydraulic manifold
Why can a hydraulic manifold not be deburred mechanically?
Why is a burr in the channel a cleanliness problem?
Is the hydraulic manifold inspected once or twice?
Can the water jet also produce a chamfer?
What do you need before a machine is discussed?
Direct contact
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Pettendorf bei Regensburg
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Technically responsible for this page: Günther Zippel — International Sales & Technical Consulting