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Compressors
- Parts
- Repair and refurbishment
- Overhaul and field services
- Reverse engineering
UNEW Industries manufactures, repairs and reverse engineers the parts of process compressors — centrifugal, axial, integrally geared, reciprocating and screw — and overhauls the machines they run in. Rotors, impellers, diaphragms and blading are made and repaired to the same aerospace standard as our gas turbine compressor blading, which has run more than 60,000 equivalent operating hours in service.
We work for refineries, petrochemical and fertilizer plants, gas processing and power producers. One supplier for the parts, the repair and the outage, for every compressor make in the plant.
What We Do
| Line | Scope |
|---|---|
| Parts supply | Capital parts and consumable spares for every compressor type — rotors, impellers, diaphragms, blading, bearings, seals, valves, pistons, rings and packing — new manufacture from our own technical data |
| Repair and refurbishment | Rotor and impeller repair, re-stack and high-speed balancing; cylinder, valve and packing rebuild; screw rotor restoration |
| Overhaul and field services | Minor and major overhauls, rotor exchange, alignment, field balancing, vibration analysis and performance testing |
| Reverse engineering | Replacement parts for obsolete, discontinued or OEM-only designs, manufactured to UNEW technical data |
Compressor Types We Support
| Type | Standard | Typical service |
|---|---|---|
| Centrifugal | API 617 | Process gas, refinery recycle and wet gas, ammonia and syngas, LNG, pipeline and gas lift |
| Axial | API 617 | FCC main air blowers, air separation, large process air |
| Integrally geared | API 672 | Plant and instrument air, nitrogen, CO₂, oxygen |
| Reciprocating | API 618 | Hydrogen make-up and recycle, PE and PP reactor feed, gas processing, fuel gas |
| Screw | API 619 | Refrigeration, flare gas recovery, fuel gas, process gas |
Parts are supplied for Elliott, Dresser-Rand / Siemens Energy, MAN Energy Solutions, Nuovo Pignone / Baker Hughes, Mitsubishi, Atlas Copco, Sulzer, Ingersoll Rand, Ariel, Burckhardt, Howden, Kobelco and all other makes on request.
Parts Supply
Centrifugal and Axial Compressors
| Group | Components |
|---|---|
| Rotor | Complete rotors, shafts, impellers (shrouded and open, welded, milled and brazed), balance pistons, thrust collars, coupling hubs |
| Stationary flow path | Diaphragms and return channels, inlet guide vanes, diffusers, axial stator vanes and carriers |
| Axial blading | Rotor blades and stator vanes, all stages, machined from bar or forging with root form to the original |
| Bearings and seals | Tilting-pad journal and thrust bearings, labyrinth and abradable seals, oil-film seals, dry gas seals and separation seals — see the Mechanical Seals page |
| Casing hardware | Casing bolting, split-line studs, end covers, bearing housings |
Integrally Geared Compressors
Impellers, pinion shafts and bull gears, tilting-pad and thrust bearings, inlet guide vane assemblies, diffusers, shaft seals and intercooler bundles.
Reciprocating Compressors
| Group | Components |
|---|---|
| Cylinder | Cylinder liners, valves and valve internals (plates, rings, springs, seats and guards), unloaders, cylinder heads |
| Piston assembly | Pistons, piston rods, piston rings and rider bands, rod nuts, crossheads and pins |
| Packing | Pressure packing cases and rings, wiper packing, partition packing |
| Running gear | Connecting rods, main and crankpin bearings, crosshead shoes, crankshaft repair |
Screw Compressors
Rotor sets — male and female — bearings, slide valves and capacity control parts, shaft seals, timing gears and casing wear parts.
Consumables
Every overhaul consumes a defined kit of parts. We supply complete overhaul kits or individual items: gaskets and O-rings, bolting, shims, bearing and seal kits, valve kits for reciprocating machines, filters, and the hardware consumed at each minor and major overhaul.
Materials and Coatings
| Component | Materials | Coating and treatment |
|---|---|---|
| Impellers and rotors | 17-4PH, 15-5PH, 410 / F6NM martensitic stainless, Duplex, Inconel 718, Ti-6Al-4V | Anti-fouling and anti-corrosion coatings (fluoropolymer, electroless nickel), erosion-resistant HVOF coatings |
| Axial blades and vanes | 17-4PH, 403 / 410, X22CrMoV12-1, Ti-6Al-4V, Inconel 718 | Anti-corrosion and erosion-resistant coatings; shot peening |
| Diaphragms and casings | Cast and fabricated carbon and stainless steel, ductile iron | Coatings to service |
| Bearings | Babbitt on steel backing; tilting-pad steel and bronze | Babbitt rebond and re-machining |
| Reciprocating valves, rings and packing | PEEK, PTFE and carbon-filled composites, Nimonic and stainless valve plates and springs | Non-lubricated and lubricated grades |
| Piston rods and screw rotors | 4140, 17-4PH, Inconel 718; screw rotors in carbon and stainless steel | Tungsten carbide HVOF, hard chrome, nitriding |
Repair and Refurbishment
We repair rotors, impellers, cylinders and screw rotor sets of any make. The removed part is inspected before anything is decided.
Incoming Inspection
| Finding | What it tells us |
|---|---|
| Fouling and polymer build-up on impellers and diaphragms | Process carry-over — the coating and the wash system, not only the rotor |
| Vane erosion and leading-edge wear | Liquid or solids in the gas; material and coating selection |
| Corrosion pitting and stress corrosion cracking | Wet, sour or chloride service; material upgrade required |
| Rubs at seals and shroud | Rotor dynamics, thermal growth or bearing condition |
| Fatigue cracks at impeller welds and blade roots | Resonance or surge history; repair or replace decision |
| Valve plate breakage, ring and rider wear, rod scoring | Reciprocating machine — valve dynamics, lubrication and alignment |
| Rotor contact and bearing damage on screw sets | Bearing life, timing gear condition, liquid slugging |
Refurbishment Process
| Step | Operations |
|---|---|
| 1. Receipt and inspection | Serial record, disassembly, run-out and dimensional record, NDE of shaft, impellers and blades, repair classification |
| 2. Rotor de-stack | Impeller and sleeve removal by controlled heating or hydraulic fit, component-level inspection |
| 3. Repair | Impeller vane and shroud weld repair and re-machining, shaft journal and fit restoration by weld build-up or plating, blade repair or replacement, seal and bearing surface restoration |
| 4. Re-stack and balance | Re-stack to original stack-up, low-speed component balancing, high-speed balancing and overspeed test of the assembled rotor |
| 5. Coating and protection | Anti-fouling, anti-corrosion and erosion-resistant coatings; protective packing in rotor cradles |
| 6. Release | Refurbishment report per serial number, balance and NDE record, certificate of conformance |
Reciprocating machines: cylinder re-boring and lining, valve rebuild, packing rebuild, piston rod re-coating and grinding. Screw machines: rotor set restoration, bearing and seal replacement, clearance setting. Rotors for critical machines are held on exchange — a refurbished rotor from UNEW inventory is delivered at the outage and the removed rotor is repaired afterwards.
Overhaul and Field Services
| Service | Scope |
|---|---|
| Minor overhaul | Bearings, seals, valves and packing; alignment and clearance record without removing the rotor |
| Major overhaul | Casing opened, rotor removed and exchanged or repaired, diaphragms and flow path inspected, bearings and seals renewed, alignment, reassembly and test |
| Rotor exchange | Refurbished rotor from inventory installed at the outage |
| Alignment and field balancing | Laser alignment of compressor train, driver and gearbox; in-situ balancing |
| Vibration and performance | Vibration analysis, performance and surge-line testing, fouling and efficiency assessment |
| Re-rate | Re-wheel and re-rate studies where the process has moved away from the original design point |
| Forced-outage response | Rapid mobilization of a technical advisor and crew with parts from inventory |
Field crews, tooling and outage management are described on the Turbine Services page; the same crews and the same reporting apply to compressor outages.
Reverse Engineering
We hold the technical data for every part we supply. Where a part is obsolete, discontinued, available only from one maker, or not yet in our library, we reverse engineer it from a used sample and make it a UNEW product.
| Step | Scope |
|---|---|
| Geometry capture | 3D optical scanning and CMM measurement of impellers, diaphragms, blades, rotors, valves and pistons; flow-path geometry reconstructed from the scan |
| Material analysis | Composition, hardness and microstructure of the base material; identification of coatings and composites |
| Engineering | UNEW drawings, datasheet, stack-up and balance specification; material and coating upgraded where the failure history calls for it |
| First article | Manufacture, inspection, balance and test; UNEW part number cross-referenced to the original |
From the first order onward the part is manufactured to UNEW data, and repeat orders, spares and repairs are all made to the same data. The plant is no longer dependent on one maker for one old machine.