Schwing — German hydraulic engineering reliability
Schwing GmbH (Herne, Germany) has been manufacturing concrete pumps since 1934. The company is known for robust construction, dependable hydraulic components, and strong suitability for road and bridge projects. Together with Stetter (Memmingen), they form Schwing-Stetter Holding — a complete ecosystem of concrete plant and pumping equipment.
PHS Magnum services Schwing pumps across multiple generations. Our specialisations: hydraulic system repair, Rock Valve reconditioning, and boom crack repair with certified welding.
Models covered
Boom pumps — S-Series
- S 28 X — standard segment (~28 m reach)
- S 36 X, S 38 SX — the most popular and versatile models
- S 43 SX, S 47 SX, S 51 SX, S 56 SX — large civil projects, bridges, high-rise structures
S-Series designation: the number indicates the boom’s vertical reach in metres.
Boom construction: hardened steel with NDT-tested welds. Hydraulic section control, hydraulic outriggers, and pump stabilisation systems throughout.
Stationary pumps
- BPL (Boom Pump Light) — compact models
- BP, SP — larger stationary pumps
High operating pressures (up to 380 bar), output capacities up to 200 m³/h. Widely used in ready-mix plants and infrastructure construction.
Mixer-pumps FBP
A hybrid combining a Stetter truck-mounted mixer with a Schwing pump. The key consideration: both systems share one vehicle, but each has distinct service requirements — the drum (paddles, drum seals) and the pump are maintained separately.
Rock Valve — design detail
Schwing uses the Rock Valve instead of the S-valve (Putzmeister) or ball valve (Cifa). The design: an oscillating wear-plate assembly, hydraulically actuated, that directs concrete flow from cylinder A or B.
Rock Valve advantages
- Simpler geometry — easier to clean and inspect
- Replaceable wear plates (rather than replacing the entire valve assembly as with an S-valve)
- Handles coarser concrete mixes well (e.g., road-grade mixes with basalt aggregate)
Rock Valve limitations
- Wear plates degrade faster with abrasive aggregate (the plates are a consumable)
- Regular wear-plate replacement required (every 50,000–80,000 m³, compared to 80,000–150,000 m³ for an S-valve)
- The oscillating geometry creates slightly higher pressure pulsations — less critical, but it does affect hose longevity
Rock Valve wear-plate replacement procedure
- Remove the valve cover (15–20 minutes)
- Extract the worn wear plates
- Clean the mounting surfaces (hand or mechanical grinding)
- Fit new wear plates to the specified torque setting
- Pressure test and trial run
Time: 2–4 working hours. Wear-plate cost (full set) varies by pump model — ask for a quote.
Schwing boom repair
Schwing booms are solidly built from steel, but like any structure subject to cyclic loading, weld cracks can develop after a high number of cycles — typically after 5–10 years of intensive operation.
PHS Magnum procedure:
- Full boom NDT — magnetic particle (MT) or penetrant (PT) inspection of all welds to establish the extent of any cracking
- Crack mapping — photography and technical diagram
- Surface preparation — grinding the area around the crack back to clean, sound material
- MMA/MIG welding — certified welder to ISO 9606-1, procedure in accordance with Schwing’s WPS (Welding Procedure Specification)
- Post-repair NDT — weld quality verification
- Protective coating — priming and topcoat paint
Timeframe: 2–5 working days. Full technical documentation and NDT report provided to the owner.
Schwing interventions — typical breakdown
| Intervention type | Frequency |
|---|---|
| Rock Valve wear-plate replacement | 22% |
| Rubber piston replacement | 25% |
| Oil and filter change | 18% |
| Hydraulic repair (valves, hoses, seals) | 12% |
| Electronics diagnostics (CAN) | 8% |
| Cylinder reconditioning | 6% |
| Boom crack repair | 5% |
| Cooling water pump repair | 4% |
Mobile Schwing service
A mobile technician can attend anywhere within 200–300 km of Chorula. Services performable on site:
- Rock Valve wear-plate replacement (a straightforward procedure, fully achievable in the field)
- Rubber piston replacement
- Hydraulic oil change
- Diagnostics and fault code clearing
- Minor hydraulic repairs
What requires a workshop: cylinder reconditioning, boom crack repair (requires NDT and specialist welding conditions), bodywork, TDT inspection.
