Overview

Valve plate chemical etching is the photochemical route to flat metal valve plates, where flow channels, sealing lands and reed slots are dissolved into spring steel or stainless strip instead of being milled or stamped. A photoresist mask is laminated, exposed and developed on the sheet, and a matched etchant removes the unprotected metal to a controlled depth, so shallow channels and through ports are formed in the same pass while the plate stays flat. Stock is typically spring steel (65Mn, SAE 1075/1095), 301/304/316L stainless and dedicated valve steel, from 0.10 mm to 1.00 mm thick.

Because valve plate chemical etching adds no mechanical load, there is no stamped shear edge or residual tensile stress to start a fatigue crack, which is the main failure mode of a compressor valve. Channel depth holds ±0.01 mm, outline ±0.02 mm and flatness within 0.02 mm per 100 mm, so the sealing land seats evenly and the reed opens at a repeatable pressure. Deburring, lapping, nitriding or soft-nitriding for fatigue life, rust prevention and stress-relief annealing follow on the same line.

Parameter Window

• Available Materials: spring steel (65Mn, SAE 1075/1095), 301/304/316L stainless, valve steel
• Material Thickness Range: 0.10–1.00 mm (0.20 / 0.40 / 0.80 mm standard)
• Tolerance: ±0.01 mm on channel depth, ±0.02 mm on outline, flatness ≤ 0.02 mm per 100 mm
• Minimum Feature: 0.15 mm channel width, 0.02–0.30 mm channel depth, 0.20 mm port
• Surface Options: deburr, lap / polish, nitride or soft-nitride, rust inhibitor, stress-relief anneal
• Compliance: ISO 9001 process control, RoHS/REACH material traceability

Manufacturing Process / Workflow (8 Steps)

1. Artwork & Channel Map — Convert the plate drawing to vector artwork, separate half-etch channels from through ports, and set compensation for the alloy and depth.
2. Material Selection — Choose spring steel for fatigue strength or 301/316L stainless for corrosion resistance, then level the sheet to the required flatness.
3. Cleaning & Lamination — Degrease and laminate dry-film resist on both faces so channel and port patterns register on the flat blank.
4. UV Exposure — Expose both sides through registered film, aligning channels, sealing lands and bolt holes to the plate datum.
5. Development — Wash out unexposed resist to open channel and port windows, then check that narrow grooves are fully cleared.
6. Etching — Spray etchant matched to the alloy, controlling time and temperature to hit channel depth without undercutting the sealing land.
7. Stripping & Finishing — Remove resist, neutralize, deburr, lap the sealing face, then nitride or soft-nitride and apply rust inhibitor.
8. Inspection & Packaging — Measure channel depth, flatness, sealing-land width and surface finish against the approved sample, then pack flat in trays.

Core Advantages

1. Flat sealing lands: Chemical removal leaves the sealing face flat and undistorted, so the reed seats evenly and leakage stays low.
2. No stamping fatigue source: There is no work-hardened shear edge or residual stress, so the plate resists crack initiation under millions of cycles.
3. Channels in one pass: Shallow flow grooves, half-etched steps and through ports are produced together, with no milling setup per groove.
4. Controlled groove depth: Channel depth holds ±0.01 mm across the panel, so flow area and reed lift stay repeatable part to part.
5. Low-cost design changes: A new channel layout is a new film, so variant plates and small batches need no new die or fixture.
6. One flat plate, many features: Valve plate chemical etching puts channels, ports, sealing lands and half-etched steps in a single flat part without stacked machining operations.

Typical Applications

• Refrigeration compressor valves: Flat suction and discharge plates with etched channels and reed seats.
• Air compressor valve plates: Spring-steel plates with half-etched flow grooves for reciprocating compressors.
• Vacuum pump valves: Thin, flat plates with fine channels for dry and oil-lubricated pumps.
• Hydraulic valve plates: Channel and port patterns etched into stainless for compact manifolds.
• Reed valve retainers: Half-etched steps and slots that locate and limit reed travel.
• Prototype & test plates: Short-run channel variants for flow and fatigue testing before hard tooling.

Design Notes & Process Considerations

1. Channel depth callout: Specify groove depth (commonly 0.02–0.30 mm) and remaining thickness, and mark through ports separately from half-etched channels.
2. Sealing-land width: Keep the sealing land wide enough relative to depth, or undercut may narrow the seat and raise leakage.
3. Flatness requirement: Call out flatness per 100 mm and the lapping finish, since the reed seats directly on this face.
4. Fatigue and surface treatment: Name the nitriding or soft-nitriding case and target hardness; compressive surface stress extends cycle life.
5. Material and temper: State the grade and temper; spring steel needs stress-relief annealing, stainless needs corrosion control.
6. Datum and port alignment: With valve plate chemical etching, give bolt holes, port centers and a single datum so channels register to the mating body.