Steam Turbine Parts Manufacturing

Greno Industries manufactures steam turbine parts for power generation industry leaders like GE Vernova and Siemens Energy. Whether you need a regular steam turbine parts manufacturer or periodic support for service work, we have the capabilities and experience that you require. 

Steam Turbine Parts and the Greno Advantage

Today’s steam turbines operate in environments involving extreme pressure, high temperatures, and continuous rotational forces to satisfy the grid’s current power demand. The components inside these machines must maintain precise alignment and dimensional stability to ensure efficient energy conversion and long service life.

Greno uses precision manufacturing to make steam turbine parts that withstand demanding conditions and meet stringent requirements. With our extensive experience machining high-temperature alloys and precision components, Greno supports both new turbine builds and turbine service work. We also offer kitting services.

Whether you need a regular steam turbine parts manufacturer or periodic support for service work, contact us.

Precision Machining for Steam Turbine Components

Gas turbine components often require tight tolerances, high-strength materials, and specialized manufacturing. Many parts are produced from difficult-to-machine alloys such as Inconel, stainless steels, and alloy steels that must perform reliably in high-temperature environments.

Greno’s machining processes support:

• Large-diameter turning for turbine rings, casings, and rotor components
  

• 3-axis and 4-axis CNC milling for complex geometries and precision alignment features
  

• Gun drilling for deep internal passages and lubrication channels
  

• Welding and hardfacing for wear-resistant components
  

• Precision inspection and nondestructive testing

These capabilities allow Greno to support both the top OEM turbine manufacturers and field service companies performing turbine repair and overhaul.

Component Kitting for Steam Turbine Parts

A competitive advantage of Greno Industries is our ability to both make and buy industry components in order to consolidate (or kit) your shipment, thus reducing lead times and ensuring multiple bill of material line items are procured.  

With our in-house machining capabilities, we can cut down the cycle by ensuring the buy items are ready to ship when longer-lead machined components are complete.  All items are packed and preserved according to our customer’s requirements to be delivered for final assembly or to site for outage replacement.

Steam Turbine Component Materials

Steam turbine parts are commonly produced from materials engineered for high-temperature strength and corrosion resistance. Greno routinely machines materials such as:

• 422 stainless steel

• 17-4 PH stainless steel

• 416 stainless steel

• Alloy steels

• Inconel and other nickel-based alloys

• High-temperature specialty steels

These materials ensure reliable performance under thermal cycling, high pressure, and severe vibration.

Parts Manufacturing for Steam Turbine OEMs and MROs

Steam turbines often require replacement components during scheduled outages or maintenance events. Greno works closely with steam turbine original equipment manufacturers (OEMs) and turbine maintenance, repair, and overhaul organizations (i.e., steam turbine MROs) to produce precision replacement parts that meet exact engineering specifications.

Our machining capabilities allow us to manufacture both custom one-off components and repeat production parts, ensuring that steam turbine operators can quickly return equipment to service.

Steam Turbine Parts from Greno Industries

Some examples of the steam turbine components we work with are:  

Air Deflectors

Air deflectors are machined metal components that guide steam or air away from sensitive components to optimize turbine efficiency. They’re often made of alloys like 416 or 17-4PH stainless steel. 

Alignment Keys

Alignment keys (guide keys, radial keys, gib keys) maintain the proper centering and alignment of turbine casings, diaphragms, and bearing pedestals relative to the rotor centerline. After 3 axis or 4 axis milling, these steam turbine parts are ground to an exact, uniform thickness. 

Atmospheric Relief Diaphragm

Atmospheric relief diaphragms are installed on the low-pressure exhaust hood to prevent casing failures from over-pressure. They’re machined into thin discs that help release steam to the atmosphere if the internal pressure becomes too high.

Balance Plugs 

Balance plugs (balancing plugs, screw plugs) are threaded weights used during in-service field balancing. They’re inserted into pre-tapped holes to allow for precise trim balancing without removing the rotor from the casing. 

Balance Weights

Balance weights (balancing weights) are also steam turbine parts that correct vibrations in rotors. Unlike balance plugs, however, balance weights are installed during initial manufacturing or major overhauls.  

Bearing Lock Pins

Bearing lock pins (turbine blade locking pins) secure blades to the rotor disc. They’re made of high-strength materials such as H11 steel (ASTM A681-08). Typically, these steam turbine pins fit into a notch in the blade and a groove in the rotor disc. 

Bearing Seals

Bearing seals prevent steam leakage into bearing housings. They’re machined from low-friction materials that can withstand high temperatures and pressures. Examples include stainless steel 416 or 17-4ph.  

Bearings

Steam turbine bearings support the rotor shaft while reducing friction and managing high loads, speeds, and temperatures. Precision machining can achieve geometries such as spherical contours for alignment or cylindrical bores for hydrodynamic support.

Bolts

Steam turbine bolts are high-strength fasteners that can withstand extreme temperatures and pressures. They’re made of materials like A286, Incoloy 800H, or 17-4PH for superior strength at high temperatures.

Bonnets

Bonnets are steam turbine parts that contain valve pressures. They’re often made of Inconel and produced through turning. Bonnets require precision machining for attachment to the valve body and may feature drilled vent ports. 

Castellated Nuts

Castellated nuts (castle nuts) for steam turbines are high-strength fasteners with slotted, crown-like tops. They prevent joints from loosening under high stress, extreme vibration, and thermal cycling. 

Collars

Steam turbine collars (thrust collars, thrust runners) manage axial movement, handle thrust loads, and maintain rotor positioning. They can be machined directly onto the turbine rotor shaft or fitted onto it.  

Coupling Covers

Coupling covers are steam turbine parts that contain oil mist and keep foreign object debris out of the coupling area. These machined metal parts require precision manufacturing for proper alignment and oil-tight sealing.  

Coupling Guards

Coupling guards enclose the high-speed coupling between a turbine and its driven machine. These safety covers are fabricated  from carbon steel and can have solid box or split clamshell designs. TIG welding may be used during assembly.

Covered Nuts

Covered nuts (cap nuts) for steam turbines are high-strength fasteners that are designed to withstand extreme operating conditions. They provide a secure fitting and come in sizes ranging from M36 to M100. Precision threading is used for even load distribution. 

Covers

Covers wrap are steam turbine parts that wrap around casings to minimize heat loss and promote safety. These precision-machined parts keep surface temperatures close to the ambient environments and are often made of stainless steel. 

Cylinders

Steam turbine cylinders (casings) house internal rotating parts and stationary blades. The inner and outer surfaces are precisely machined to ensure a perfect, leak-proof seal. Heat treating improves tensile strength and reduces internal stresses. 

Diaphragm Support Bars

Diaphragm support bars are adjustable steam turbine parts that hold heavy diaphragm segments in the correct vertical position. These metal bars are precisely machined to fit the specific curvature of the diaphragm and the casing shoulder.

Dowels

Dowels are cylindrical or tapered fasteners for aligning, positioning, and stabilizing mating components such as casing halves or diaphragms. These machined metal parts are ground to extremely tight tolerances to ensure a proper fit.

Fabrications, Small

Steam turbines contain many small metal fabrications. Examples include blades, nozzles, and valve components. CNC milling is used to achieve precise tolerances for blade forms. Heat treatment is used to relieve stresses and achieve the desired hardness.

Flanges

Flanges are high-strength, metal rings that create secure, leak-proof connections for steam piping and turbine castings. These large-diameter parts are machined to their final dimensions using large lathes.  

Gaskets

Steam turbine gaskets prevent steam leakage, withstand extreme pressures, and handle high temperatures between turbine flanges. To provide strength, stainless steels (304, 316), nickel, titanium, and Inconel are used.

Gibs

Gibs are wedge-shaped metal components that manage thermal expansion by controlling the lateral or rotational movement of the turbine casing. These steam turbine parts require precision machining to meet exact tolerances and may be custom-fitted.  

Hex Nuts

Hex nuts secure components under extreme pressure, high temperature, and severe vibration. These six-sided, internally threaded fasteners are made of high-strength alloys and are larger and thicker than standard nuts.

High Alloy Bolts

High alloy bolts are specialized fasteners that require heat treatment and thread rolling to ensure high creep resistance and structural integrity. These steam turbine parts may require precision grinding and anti-galling coatings to aid with assembly.

High Alloy Studs

High alloy studs are machined metal parts that ensure tight, reliable clamping for steam turbine casings. Blanks made of Inconel, stainless steel, or specialized alloys are machined to the stud’s profile. 

Inconel Fasteners

Inconel fasteners are made of high-strength, nickel-chromium-molybdenum superalloys. They’re designed to secure parts under extreme high-temperature and high-pressure conditions. Surface treatments may be necessary to meet precise tolerances.

Inlet Pipes

Inlet parts such as stop valves, control valves, nozzles, and inlet casings regulate and direct high-pressure steam into the turbine. These steam turbine parts are made of high-grade cast steel or alloy steels that require precision machining.

Keeper Rings

Keeper rings (carbon ring seals) are segmented, self-lubricating seals that are installed around the shaft to prevent steam leakage. Metal  is machined into precise ring shapes and then cut into segments (usually three) to allow for expansion and contraction.

Keys

Keys are steam turbine parts that securely lock rotating components such as turbine wheels, discs, or couplings onto the rotor shaft. Milling, grinding, and finishing are used to achieve tight tolerances. Often, keys are tumbled or polished to achieve a precise fit. 

Lifting Devices

Lifting devices such as lifting beams, yokes, and tailored slings are steam turbine parts for lfiting and positioning high-mass components like rotors and casings. Manufacturing involves precision welding of the main beam body.

Lock Plates

Lock plates are specialized fasteners that secure turbine blades axially to the rotor disk. CNC milling or grinding is used to achieve precise dimensions, including the creation of castellated (toothed) edges for locking.

Lugs

Steam turbine lugs connect blades and minimize vibration-induced failure.They’re designed according to ASME standards (specifically Section I or VIII) and, in the case of turbine casing lugs, may be welded directly onto the turbine casing.  

Oil Deflectors

Oil deflectors are ring-like components that prevent lubricating oil from leaking. They also stop contaminants from entering the housing. These steam turbine parts are heat-shrunk onto the shaft and require tight tolerances.

Oil Seal Rings

Oil seal rings prevent steam leakage along the rotor shaft and block oil from escaping the bearing housings. They’re assembled from multiple, precision-machined segments that are held together by garter springs to maintain close tolerances.

Orifice Plates

Orifice plates are thin, metal discs with a central hole for measuring steam flow rate. The central hole is precisely bored, and the downstream side can be beveled to a specific thickness. A handle may be welded onto a plate that is polished to remove burrs.

O-Rings

Steam turbine O-rings are metallic seals that are installed between machined components to prevent high-pressure steam leakage. When pressed into a groove, the O-ring forms a tight seal that prevents fluid or gas from escaping.  

Packing Rings

Packing rings are steam turbine parts that are installed between turbine stages and at shaft ends to minimize steam leakage and prevent pressure loss. The ring segments are precision machined and then curved into an arc shape.

Pilot Valves

Pilot valves are small, highly precise control mechanisms for managing the flow of hydraulic oil or steam. The main body and spool (piston) are machined to extremely tight tolerances, which are critical for oil flow control.

Pins

Steam turbine pins are high-strength fasteners for securing turbine blades to the rotor disk and ensuring correct positioning. Manufacturing involves the precision reaming of holes for a tight fit and careful machining to avoid stress concentrations.

Piston Rings

Piston rings are steam turbine parts that create a dynamic seal between the piston and the cylinder wall to minimize leakage and maximize pressure. These metallic rings are cut from a cylinder and then split and machined to the precise size that’s needed for the piston groove.  

Piston Rods

Piston rods connect the piston to the crosshead and transmit reciprocating power. A forged rod made of high-strength steel is turned on a lathe to precise dimensions. To minimize packing wear and leakage, the surface is hardened and ground to a very smooth finish.  

Pistons

Steam turbine pistons slide within a cylinder and are driven by steam pressure to create linear motion. Cast or forged metals are precision machined to create ring grooves and then polished to ensure a tight fit that allows movement. 

Radial Spill Strips

Radial spill strips in steam turbines are thin, metal seals that are positioned over the tips of rotating buckets (blades) to minimize steam leakage. They create a narrow, labyrinth-like path for steam and can be machined with sharp edges.     

Reamers

Reamers are multi-edged rotary cutting tools for finishing and sizing pre-drilled holes for blade roots, casings, and couplings. They’re manufactured from high-speed steel, carbide, or cobalt steel to ensure hardness and toughness.

Shims

Shims in steam turbines are thin metal plates used for aligning, leveling and spacing components. They’re often machined from high-grade stainless steel and ground to ensure high parallelism, flatness, and burr-free surfaces for even load distribution. 

Sleeves

Sleeves (liners, shaft sleeves) are inserted into bores, onto shafts, or used in bearings to reduce friction, improve durability, and simplify maintenance. These replaceable steam turbine parts need high dimensional accuracy for a proper fit. In some cases, they require heat treatment.

Spacer Plates

Spacer plates (rotor discs) maintain accurate spacing between rotor discs or blades. CNC milling and turning are used to achieve precise dimensions. Rigorous inspections are needed because of the risk of cracking over long periods of use.  

Spacers

Spacers are installed between turbine discs, blades, or windings to maintain precise axial alignment. Precision machining can achieve the tight tolerances for shaft alignment. In house non-destructive testing (NDT) is used to detect crack formation after long-term service. 

Stub Shafts

Stub shafts are short, cantilever shaft extensions that transmit torque from the main rotor to generators or gearboxes. The shaft is shaped with precision machining, often with significant amounts of material removal. Turning, drilling, and grinding are also used. 

Turbine Studs

Studs are high-strength, headless fasteners with threads on both ends. These steam turbine parts are used to secure turbine casings, valves, and other components. Studs require precision machining. 

Support Bar Shims

Support bar shims adjust the vertical position and alignment of diaphragm segments within the turbine casing. Precision cutting allows for custom shapes that match the profile of the diaphragm. After cutting, support bar shims are deburred and cleaned.

Support Bar Spacers

Support bar spacers maintain precise gaps between stationary and rotating parts. They’re also used to ensure proper diaphragm alignment. These steam turbine parts are turned on a lathe to achieve the required diameter and then drilled, faced, and parted-off to the specific length.   

Thermocouple Accessories

Thermocouples accessories include protective metal thermowells, connectors and head assemblies, and mounting hardware. To withstand thermal shock and corrosion, they’re made of stainless steel, Inconel, or exotic alloys.  

Thrust Bearing Shims

Thrust bearing shims are thin metal spacers for adjusting the axial position of the rotor shaft. These steam turbine parts are designed to prevent excessive axial movement and manage high thrust loads. Precision machining is used to meet strict tolerance requirements.

Transport Devices

Transport devices (shipping braces, restraining fixtures) are temporary mechanical components that lock the rotor to the casing. These steel parts are precision-machined to ensure a secure, tight fit that prevents any movement of the rotor during transit.   

Washers

Washers are high-strength fastening components that maintain bolt tension and prevent loosening caused by intense vibrations and thermal cycling. These steam turbine parts are manufactured from hardened, heat-resistant steel alloys using precision machining.   

Worm Wheels

Worm wheels are high-ratio helical gears that mesh with a steel screw (worm) to transform high-speed rotational motion into lower-speed, high-torque output. After the gear blank is gashed, the teeth are hobbed. Steel gears may undergo heat treatment for hardness.  Worms

Worms (worm gears) are screw-like gears that change rotational motion by 90 degrees and achieve high gear ratios within compact spaces. They’re made of high-grade steel alloys and produced using hobbing, milling, and grinding.

Steam Turbine Valve Components

Greno Industries has extensive experience manufacturing steam turbine valve components for power generation equipment. These engineered-to-order, critical-path components regulate steam flow, pressure, and turbine speed to ensure safe and efficient turbine operation. Typical parts include main stop valves, control (governor) valves, intercept valves, and reheat stop valves used in industrial and utility-scale steam turbines.

Manufactured from high-strength alloy steels and high-temperature materials, these components require precision machining to maintain tight tolerances and reliable performance in demanding operating environments. Valve seats and discs are often enhanced with stellite hardfacing, improving resistance to erosion, wear, and metal-to-metal contact while extending component service life.

Common steam turbine components we have supported include the following.

Balance Chambers

Balance chambers (balance pistons, balance drums) counteract the intense axial thrust that’s generated by high-pressure steam flowing through the turbine blades. These large-diameter discs or drums work directly with the valve stem and valve cap to seal and contain the internal pressure of the valve. Without pressure balancing, the full steam pressure would act on the valve disc or plug, creating very large forces that the actuator would need to overcome. The balance chamber helps neutralize much of this force. 

Valve Camshafts

Camshafts are metal rods with multiple lobes that control the opening and closing of steam valves in turbines. These steam turbine parts require extensive machining, grinding, and heat treatment to ensure durability under high pressures and temperatures.  

Crossheads

Steam turbine crossheads are sliding mechanical joints that connect the valve stem to the connecting rod. They convert linear piston motion to rotary motion and are machined to high precision and. Hole drilling and thread tapping are typically required.

Valve Bushings

Steam turbine bushings allow the valve stem to slide with minimal resistance. They also reduce friction and minimize vibrations. Bushings are precision-bored, cylindrical shapes that are produced with CNC lathes. 

Pressure Seal Heads

Pressure seal heads are steam turbine parts that tighten automatically as internal system pressure increases. They’re made by machining a segmented or solid stainless steel forging that connects precisely with the valve disc. These designs are commonly used in main stop valves, intercept valves, and control valves where steam pressures and temperatures are extremely high.

Valve Seats

Valve seats provide a leak-proof, metal-to-metal seal to control high-pressure steam flow. These steam turbine parts are precision-machined to ensure a tight fit with the valve disc. The seating surface may be hardfaced to improve wear resistance.

Steam Seal Rings

Steam seal rings (gland seals) are used between the valve disc and stationary balancing component to regulate steam leakage. These metallic seals are fabricated by machining thin-finned rings that are fitted into the valve internal components. 

Stems

Valve stems are the main shafts of the valve that runs the length of the casing. These steam turbine components require the high-precision machining of forged Inconel bar stock. Machining operations include turning, groove-cutting, and drilling with some special processes also required.  

Valve Casing Fasteners

Greno Industries manufactures engineered-to-order steam turbine valve casing fasteners used to secure valve caps, bonnets, and pressure-containing assemblies in power generation equipment. 

These high-strength fasteners play a critical role in maintaining the pressure boundary of steam turbine valves while ensuring reliable operation under extreme temperature, pressure, and vibration conditions.

Steam turbine valve assemblies require specialized fasteners capable of maintaining clamping force during thermal expansion and high-pressure steam operation. Greno machines custom thru-studs, tap-end studs, and castellated (castle) nuts designed specifically to connect the valve cap to the valve casing in main stop valves, control valves, intercept valves, and reheat stop valves.

Engineered Fasteners for Turbine Casings and Valves

Unlike standard industrial fasteners, turbine and valve casing studs and nuts are engineered components manufactured to precise dimensional and material specifications. These custom fasteners must withstand:

• High steam pressures
  

• Elevated operating temperatures
  

• Thermal cycling during startup and shutdown
  

• Continuous vibration from turbine operation

To ensure long-term reliability, Greno machines these fasteners with tight tolerances, precise thread geometry, and consistent surface finishes.

Steam Turbine and Valve Fasteners Manufactured by Greno

Greno manufactures a variety of custom turbine valve fasteners, including:

• Thru-studs for turbine casing connections
  

• Tap-end studs for threaded valve body applications
  

• Castellated (castle) nuts for secure locking under vibration
  

• Heavy hex nuts and specialty turbine fasteners
  

• Precision-machined washers and locking hardware
  

Besides the main turbine casing, these fasteners are commonly used in main stop valves, control valves, intercept valves, and reheat stop valves in industrial and utility-scale steam turbines.

High-Temperature Steam Turbine Fastener Materials

Steam turbine valve fasteners must maintain strength and dimensional stability under extreme operating conditions. Greno machines fasteners from high-performance materials such as:

• Inconel 718

• Durehete 1055

• Alloy steels (4140, 4340)

• 400 Series stainless steels

• High-temperature alloys

• Specialty turbine-grade materials specified by OEMs

Material selection is critical to ensure resistance to creep, corrosion, and thermal fatigue in high-energy steam environments.

Precision Manufacturing for Critical Turbine & Valve Hardware

Because turbine valve fasteners are part of the pressure boundary of the turbine and valve assembly, they must be manufactured with strict attention to dimensional accuracy and material integrity. Greno’s machining capabilities and inspection equipment allow us to produce both replacement fasteners for turbine maintenance outages and custom hardware for new equipment manufacturing.

From single replacement studs to full production runs of turbine valve hardware, Greno Industries provides the precision machining expertise required for critical power generation components.

Made in USA Manufacturer of Steam Turbine Parts

Greno Industries is a Made in USA manufacturer of precision steam turbine components serving both original equipment manufacturers (OEMs) and maintenance, repair, and overhaul (MRO) providers in the power generation industry.

With decades of machining experience and advanced CNC capabilities, Greno produces engineered components designed to perform reliably in the high-pressure, high-temperature environments of steam turbine systems. Our precision manufacturing processes ensure tight tolerances, consistent quality, and dependable performance for critical turbine hardware.

Whether you require custom replacement parts, prototype components, or production quantities, Greno Industries provides the machining expertise and responsive service needed to support demanding turbine applications.

Contact Greno Industries to request a quote or discuss your steam turbine component requirements.