HELAC ALTERNATIVE
HP50-MS-RL-230-S1-C-H Rotary Actuator
Alternative heavy-duty rotary actuator for the Helac HP50-MS-RL-230-S1-C-H, a large 230-degree, rail/slide-mount (RL) helical actuator built for mining drill-rig duty. It is listed by Atlas Copco / Epiroc under part numbers 3128312643 and 3129316303 (also written 3128-3126-43 and 3129-3163-03).
Atlas part number
3128312643
Alternative rotary actuator for Helac HP50-MS-RL-230-S1-C-H — also listed as 3129316303.
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Independently supplied alternative — not an original Helac or Atlas part. Compatibility is verified before ordering.
Code anatomy
What each part of this code means
Every segment below is read from the manufacturer’s published ordering key. Where a segment is not published, we say so instead of guessing — those are the ones to confirm from the tag or the drawing before ordering.
HP50-MS-RL-230-S1-C-H
HP series
| Segment | Field | What it tells you |
|---|---|---|
| HP50 | Series and size | HP series, size 50 — the HP family uses its own key |
| MS | Measurement system | Custom design — metric threads on a special OEM build |
| RL | Housing / mounting | Rail mount (L40 style) |
| 230 | Rotation | Non-standard rotation angle (230°) — special build |
| S1 | Shaft / flanges | Cantilever — shaft flange only (single) |
| C | Valve | Counterbalance valve fitted |
| H | Seals and bearings | Standard seals and bearings |
The HP/HTX families write the size into the series field; the remaining positions follow the same order as the L-series key.
Full ordering key and how to read a tag: identifying a rotary actuator.
What the 230° sweep changes on this build
A non-standard sweep: 230° sits outside the usual 180° / 360° range, which means the stop tube was cut for that angle. A standard-angle unit will not reproduce it, and the stop positions have to be read off the drawing rather than assumed.
- Read the stop positions off the mounting drawing before ordering — do not infer them from the code alone.
- Ask why the original used this sweep; a non-standard angle usually answers a linkage constraint that a standard unit will not fit.
- Confirm the sweep on the unit tag matches the code, since special builds are sometimes re-stopped in service.
When this sweep is the right build
- Linkages whose geometry was designed around this exact sweep — the stop positions usually answer a clearance or interference constraint.
- Rebuild work where the surrounding mechanism has to stay unchanged, so the sweep cannot be normalised to 180° or 360°.
- OEM builds where the sweep was specified by the machine maker rather than chosen from a catalogue.
Confirming the sweep on the machine
- Measure the swing between the mechanical end stops on the machine, not between the positions the linkage happens to use.
- Compare the measured swing with the code on the tag; special builds are sometimes re-stopped in service.
How the sweep sits in the order code
The sweep is the fifth segment of the code, and here it carries a value outside the standard range. That value is a build instruction, not a selection from a list: it has to travel with the enquiry together with the stop positions, because the stop tube is cut for it.
Where these two builds get mixed up
- A full-turn unit is sometimes quoted where the linkage only swings half a turn, which over-travels the hose loop for no benefit.
- If a full-turn unit will not pass a quarter or half turn under load, the cause is usually hose routing or an external stop, not the actuator.
We do not publish a conversion table between sweeps. If the sweep on your unit differs from the code above, send the tag and the mounting drawing and the build is confirmed against them.
At a glance
Quick reference
- Original model
- HP50-MS-RL-230-S1-C-H
- Original brand
- Helac
- Type
- Rotary actuator
- Rotation
- 230°
- Weight
- 105 kg
- Original part no.
- 3128312643, 3129316303
Equipment reference
Known applications
Part numbers 3128312643 and 3129316303 are commonly associated with several Atlas Copco / Epiroc Boomer and Simba drill rigs. A single rig range can carry more than one turning device depending on serial number, position and build, so please confirm the fit against your machine serial number and the actuator nameplate before ordering.
If your machine is not listed, send the full model and serial number — other builds may use the same actuator.
Confirmed data only
Technical specifications
| Product type | Hydraulic rotary actuator |
|---|---|
| Rotation angle | 230° |
| Unit weight | 105 kg |
| Cross reference | The HP50-MS-RL-230 is a heavy mining build of the Helac HP series. HM confirms the exact configuration, mounting and compatibility against the unit nameplate and a drawing or photo before a replacement is supplied; ratings are not assumed from the HP number alone. |
| Further data | Torque, pressure, port and mounting dimensions are shared with the engineering drawing on request. |
HM alternative model — confirmed on inquiry. Send us your original model number, part number or machine details and we confirm the matching configuration, specifications and compatibility, then quote. The exact ordering code — rotation, output and valve arrangement — is confirmed against your unit and is not published online.
Other models in the Helac HP range
Questions
Frequently asked questions
What does the HP50-MS-RL-230-S1-C-H replace?+
It is the model code for a Helac helical rotary actuator providing 230° rotation in the 105 kg class. It is listed by Atlas under part numbers 3128312643, 3129316303. Our alternative is matched to the same rotation, 105 kg class and mounting interface.
How do I know this fits my machine?+
The same actuator is recorded on the Boomer 104, Boomer K41, Boomer K41x, Simba H1257, Simba H157, Simba S7D. Before quoting we confirm the mounting face, port position and rotation against the tag and a photo of your unit, so the replacement matches your exact build.
What is the difference between 3128312643 and 3129316303?+
Both Atlas Copco / Epiroc references are recorded against the same Helac HP50-MS-RL-230-S1-C-H turning-device configuration for mining drill rigs; the two numbers can appear across different machine builds or parts-list revisions. Send the tag from your unit and we confirm which reference and build applies before quoting.
Will this fit a Boomer 104, K41 or K41x?+
The HP50-MS-RL-230 actuator is commonly listed on the Boomer 104, K41 and K41x as well as Simba H1257, H157 and S7D rigs, but these ranges use several different turning devices in different positions and serial-number builds. We confirm the mounting face, rail arrangement, ports and 230-degree rotation against your nameplate and a photo or drawing before recommending a replacement.
Why is the exact HM model and price not shown?+
We confirm the HM model per inquiry after verifying the interface and operating parameters with you. This avoids shipping a part that looks right by model name but differs in mounting or rotation. Price is provided with that confirmed quote.
Request a check
Looking for an alternative to this model?
Send us the original model number, part number, machine model or a drawing. We check the available option and confirm specifications and compatibility for you.
- Original model / part number
- Machine brand & model
- Quantity & annual demand
- Mounting photo or drawing (if available)
Or email directly: hm@hmhydraulics.com