Energy and Power Generation

Bore 20–1000 mm, working pressure up to 500 bar, stroke 6000 mm and beyond, total length up to 16000 mm, operating temperature from -50°C to +200°C; double-acting, single-acting, telescopic and plunger designs, with position and pressure sensors built in where the control system calls for them. A dam gate or a turbine guide-vane cylinder needs a rod that survives long idle periods exposed to water. For that duty we plate a triplex Ni-Cr layer of 30+30 µm, a nickel underplate with dense chrome and a micro-crack chrome top that stops water reaching the steel through the crack network. Cylinders under cover in a thermal plant get 25–50 µm of plain hard chrome on a C45 or 42CrMo4 rod, and for abrasive slurry duty, such as a hydro intake exposed to waterborne grit, we spray 150–250 µm of HVOF ceramic instead. Synchronised multi-point lifting cylinders for transformers and heavy structures are matched in stroke and leakage across the set, and damper and valve actuator cylinders for plant auxiliaries work close to hot gas or process lines, where the seal material has to hold up under heat as well as pressure. Every cylinder is pressure tested at 1.5× working pressure for at least five minutes before it leaves the workshop.

Typical parts

• Dam gate and turbine guide-vane cylinders
• Synchronised multi-point lifting cylinders for transformers and structures
• Damper and valve actuator cylinders for plant auxiliaries
• Pitch and yaw cylinders for wind turbines

Gear, planetary, axial-piston and radial-piston motors with displacement from 0.25 to 8000 cc/rev, working pressure up to 450 bar, speed from 0.5 to 12000 rpm and operating temperature from -40°C to +120°C. A wind turbine yaw or pitch drive and a solar tracker actuator both need high torque at low speed more than raw speed, and a radial-piston motor is the design that delivers it. Mounting flanges follow SAE and DIN, so a replacement motor fits the original turbine or tracker mount without an adapter. Before dispatch each unit goes through a functional test and a pressure test against the catalogue values, and motors already in service on a turbine or a plant auxiliary can be sent in for refurbishment between planned outages.

Typical applications

• Pitch and yaw motors for wind turbines
• Drive motors for solar tracker actuators
• Radial-piston motors for power generation auxiliaries
• Pumps and motors for plant control systems

Our Schiess lathes take shafts and rods up to 2 m in diameter and 16 m long, which covers turbine shafts, generator rotor shafts and long hydraulic rods on one setup. We hold ±0.05 mm and IT6–IT7 fits, and gears for turbine and plant auxiliary drives are cut and ground up to 2000 mm in diameter to ISO 1328, with grade 7 the usual requirement for a loaded reducer stage. Hydro and thermal plants keep drives in service for decades, and gearing for this duty is carburised accordingly: case depth of 1 to 3 mm at 56–62 HRC over a core of 240–300 HB, with the material certificate and inspection record travelling with the part for the life of the asset. We also machine hydro turbine components, thermal plant parts and generator housings, and where all that is left is a worn wheel from a gearbox the manufacturer no longer supports, we measure it and cut the replacement from that.

Typical parts

• Hydro turbine components and generator housings
• Gears for turbine and plant auxiliary drives, up to 2000 mm
• Thermal plant parts and energy sector drives
• Shafts and rods up to 16 m

Control and sensor housings for turbine, tracker and plant control systems are cast in aluminium to ±0.1–0.3 mm with Ra 1.6–6.3 µm, which leaves most surfaces without machining afterward, and wall thickness can go down to 0.5–1.5 mm. Anodising, powder coating, painting and T6 heat treatment are available for housings that carry load or sit outdoors on a tracker or a turbine nacelle. Castings that hold pressure are X-rayed for porosity before they go into service.

Typical applications

• Sensor and controller housings for turbines and trackers
• Enclosures for plant control panels
• Brackets and covers for auxiliary drives

Small gears, pistons and levers in tracker actuators and plant control valves go into a project in quantities where sintering costs less than cutting each one from bar, with a further saving of up to 30% on material. Compaction pressure goes up to 800 MPa and density to 97%; tolerance is ±0.05 mm as sintered and ±0.02 mm for MIM parts. The same production line makes sintered porous filters in bronze, 316L, nickel and titanium, with pore ratings from 0.2 to 100 µm, backwashable and rated for high temperature, which suits filtration duty in plant hydraulic and process fluid systems. Every lot is checked for density, hardness and dimensions.

Typical applications

• Sintered gears and sprockets for tracker and small plant drives
• Small pistons, levers and latches for control valves
• Sintered porous filters for plant fluid systems

A choke or a valve seat in a wellhead or a flow-control line wears from the inside as the bore opens under erosion, and it keeps working the whole time it is losing tolerance. We track that bore diameter and call for replacement once it crosses the limit; there is no calendar interval behind it. For that duty we sinter tungsten carbide grades to ISO 513 in-house at 1350–1500°C, diamond grind to ±0.01 mm with Ra 0.1–0.4 µm on seal faces, and add HIP where the part has to be fully dense. In corrosive process media a standard cobalt-bound grade fails chemically before the tungsten carbide grains are even touched, so here we sinter WC-Ni grades with 9–13% nickel binder at 1400–1600 HV, holding the hardness without leaving the binder as the weak point. Parts run from 0.001 to 300 kg and from Ø3 to 500 mm.

Typical applications

• Valve cores, seal rings and choke pipe inserts for wellhead equipment
• Plunger tips for high-pressure pumps
• WC-Ni seal faces and inserts for corrosive process media
• Guide bushings and sleeves for hydraulic equipment