Description

Stainless Steel Valve Discs, Stainless Steel Diaphragms – Precision Manufacturer India

Stainless Steel Fittings India manufactures precision stainless steel valve discs, SS diaphragms, orifice plates, valve seat discs, check valve discs, butterfly valve discs, pressure diaphragms, flow control diaphragms, and diaphragm pump membranes in SS 304, SS 304L, SS 316, SS 316L, SS 316Ti, SS 2205 Duplex, SS 904L and special alloy grades. Produced by fine blanking, precision stamping, grinding, and lapping of SS sheet to tolerances of ±0.01 mm. Serving valve manufacturers, instrumentation OEMs, EPC contractors, power utilities, chemical and pharmaceutical industries globally. Price: US$ 11.60/Kilogram.

Product Overview

Stainless steel valve discs and diaphragms perform core flow control, sealing, pressure containment, and actuation functions inside valves, instruments, pumps, and pressure-regulating devices. Fine-blanked and stamped SS valve discs combine high dimensional accuracy, controlled surface finish, consistent material properties, and cost-effective volume production. Grade selection is critical: SS 316L for pharmaceutical and food-grade valve seats; SS 2205 Duplex for chloride chemical service; SS 904L for concentrated acid service where standard austenitic grades are inadequate. All products are traceable to EN 10204 3.1 Mill Test Certificates from originating SS coil heat numbers.

Stainless Steel Butterfly Valve Discs

Precision-blanked SS butterfly valve discs — wafer, lug, double-offset, and triple-offset — in SS 304, 316, 316L for valve sizes DN25 to DN600. OD tolerance ±0.05 mm; shaft hole positions CNC-punched to ±0.1 mm. Triple-offset discs precision-turned after blanking for API 609 bubble-tight metal-seat shutoff. Applications: water treatment, HVAC, food processing, pharmaceutical, and industrial process valves.

SS Check Valve Discs and Poppets

Fine-blanked stainless steel check valve discs — swing, lift, dual-plate, wafer check, and ball check seats — in SS 316L to ±0.02 mm tolerance. Perpendicular fine-blanked shear edges across 100% of thickness ensure metal-to-metal sealing integrity. Supplied to valve OEMs for API 594, API 602, and BS EN 12516 check valves in oil and gas, water treatment, chemical processing, and power plant steam systems.

SS Pressure and DP Diaphragms

Precision SS 316L pressure diaphragms, DP sensing diaphragms, capsule diaphragms, corrugated diaphragms, and flat sensing diaphragms (0.05 mm to 1.0 mm thick) for pressure transmitters, DP gauges, regulators, and safety relief devices. Stiffness, effective area, and fatigue life engineered by material grade, thickness, and corrugation geometry. Hastelloy C276 and Inconel 625 available for extreme corrosion service on enquiry.

SS Orifice Plates and Flow Restriction Discs

Fine-blanked SS 316L and 316Ti orifice plates (1.5–12 mm thick), bore diameters 1–300 mm at ±0.01 mm tolerance. Bore edges ground and lapped to ISO 5167 sharp-edge or quadrant-edge profiles. Face flatness ground to 0.05 mm per 100 mm. Calibration certificates available for custody transfer and fiscal metering orifice plates, beta ratios 0.10–0.75 per ISO 5167.

SS Diaphragm Pump Membranes

SS 316L corrugated diaphragm pump membranes (0.2–2.0 mm thick) for metering, dosing, aseptic pharmaceutical, and high-pressure process pumps. Replaces PTFE and elastomeric diaphragms in high-temperature, abrasive, and solvent services. Corrugation geometry optimises stroke volume and targets fatigue life exceeding 10 million cycles at rated stroke. FEA diaphragm stress analysis available for critical pump development programmes.

SS Valve Seat Discs and Seal Plates

Precision fine-blanked and lapped SS 316, 316L, 316Ti valve seat discs, globe valve plugs, gate wedge discs, and ball valve seat rings. Seat faces lapped to 0.001 mm (1 micron) flatness for metal-to-metal Class VI shutoff per ANSI/FCI 70-2. Hardness options: SS 316L (HRC 25-30); Stellite 6 overlay (HRC 38-42); SS 17-4PH (HRC 40-44) for erosive and high-velocity service. API 600, API 602, and BS EN 12516 compliant.

SS Diaphragm Valve Membranes and Weir Pads

SS 316L diaphragm valve membranes, weir-type pads, and straight-way diaphragm discs for pharmaceutical, biotech, food, and chemical diaphragm valve OEMs. Thickness tolerance ±5% across formed disc for consistent leak-tight seating. Pharmaceutical-grade: electropolished Ra < 0.4 μm, passivated per ASTM A967, USP Class VI and FDA 21 CFR compliant for API manufacturing and aseptic filling valve applications.

Key Features

Full SS grade range: 304, 304L, 316, 316L, 316Ti, 321, 2205 Duplex, 904L, 17-4PH
Fine blanking: ±0.01 mm bore; ±0.02 mm OD; perpendicular shear edges 100% of thickness
Valve seat lapping: 0.001 mm (1 micron) flatness for Class VI metal-to-metal shutoff
ISO 5167 orifice plates: bore ground and lapped; face flatness certified; calibration available
Diaphragm thickness range: 0.05 mm to 2.0 mm; corrugation geometry engineered for fatigue life
Electropolished Ra < 0.4 μm; passivated per ASTM A967 for pharma/food valve discs
PPAP, FAI, CMM reports, EN 10204 3.1 MTCs — full OEM documentation capability
FDA 21 CFR, USP Class VI, 3-A Sanitary Standards, API 594/598/602/609 compliance

Fine Blanking for Precision Valve Disc Manufacture

Fine blanking differs from conventional blanking by applying V-ring clamping force and counter-punch pressure before the blanking punch shears the part from the strip, preventing material fracture at the shear edge. This produces a fully-perpendicular, burnished shear edge across 100% of material thickness — critical for valve disc seating surfaces that contact elastomeric seats or metal valve bodies. Tolerances of ±0.01 mm on OD and bore eliminate secondary turning operations on most valve disc diameters, significantly reducing per-part cost versus conventionally blanked and subsequently turned valve discs.

SS Grade Selection for Valve and Diaphragm Applications

SS 316L is the baseline for valve discs in chemical, pharmaceutical, food, and general industrial service. SS 316Ti (titanium-stabilised, 1.4571) is specified for discs operating in the sensitisation temperature range (450–850°C) to prevent intergranular corrosion after high-temperature service. SS 2205 Duplex provides 2× the yield strength of austenitic grades with superior chloride SCC resistance for seawater, desalination, and high-chloride chemical valve service. SS 904L (4.5% Mo, N08904) handles concentrated sulphuric and phosphoric acid valve service where SS 316 corrodes at unacceptable rates.

Diaphragm Corrugation Design and Fatigue Life

Corrugation geometry directly controls pressure-deflection characteristics and fatigue life. Toroidal corrugations provide linear force-displacement for pressure sensor diaphragms. Convoluted corrugations maximise stroke volume for pump diaphragms. Our engineering team calculates diaphragm stress using analytical methods and FEA (ANSYS) for custom diaphragm development, ensuring maximum operating pressure, cycle life, and dimensional stability before production tooling commitment. Critical diaphragm fatigue testing to 10+ million cycles is available for new design qualification programmes.

Orifice Plate Accuracy to ISO 5167

ISO 5167 specifies strict orifice plate requirements for custody transfer metering: bore tolerance ±0.05% of bore; plate thickness uniformity ±0.001D; upstream face flatness within 0.005D; bore edge sharpness radius < 0.0004D. Stainless Steel Fittings India manufactures orifice plates to full ISO 5167-2 with bore ground and lapped, face ground flat, and edge radius verified by optical measurement. Calibration certificates for beta ratios 0.10 to 0.75 are supplied for fiscal metering and custody transfer applications in oil and gas and water industries.

Surface Quality for Sealing and Corrosion Performance

Metal-to-metal valve seats require Ra < 0.4 μm (lapped) for Class V–VI shutoff; elastomeric seat contact surfaces require Ra 0.8–1.6 μm. Pressure diaphragms require Ra < 0.4 μm to avoid fatigue crack initiation at surface stress concentrations under cyclic pressure loading. Electropolishing per ASTM B912 achieves Ra < 0.4 μm while improving corrosion resistance by selectively removing surface asperities and chromium-depleted zones, producing a chromium-enriched passive layer with PREN exceeding that of the base SS 316L material by 2–4 units.

Quality Documentation and OEM Traceability

Every batch of valve discs and diaphragms is documented with EN 10204 3.1 MTCs traceable to the SS coil heat number, CMM dimensional inspection reports, surface Ra measurement records (electropolished and lapped parts), and passivation/electropolishing test certificates. PPAP Level 1–3 documentation for automotive and industrial valve OEMs, AS9102 FAI for aerospace and defence, ISO 13485 quality records for medical device valve components, and API material certifications for oil and gas valve OEM supply are all available within our standard quality documentation framework.

Technical Specifications

Parameter	Specification
Processes	Fine Blanking, Precision Stamping, CNC Grinding, Lapping, Corrugating, Coining
Material Grades	SS 304, 304L, 316, 316L, 316Ti, 321, 347, 2205 Duplex, 904L, 17-4PH
Sheet Thickness	0.05 mm – 12 mm
OD / Bore Tolerance	±0.01 mm to ±0.02 mm (fine blanked)
Thickness Tolerance	±0.005 mm (ground/lapped)
Face Flatness (Lapped)	0.001 mm per 100 mm
Surface Roughness	Ra 0.8 μm standard; Ra < 0.4 μm electropolished; Ra < 0.2 μm implant grade
Butterfly Disc Range	DN25 – DN600
Orifice Plate Bore	1 mm – 300 mm; beta ratio 0.10 – 0.75 (ISO 5167)
Diaphragm Thickness	0.05 mm – 2.0 mm
Standards	API 594, API 598, API 602, API 609, BS EN 12516, ISO 5167, ANSI/FCI 70-2
Price	US$ 11.60 / Kilogram

Material Grades and International Equivalents

Grade	UNS	EN / W.Nr.	DIN	JIS	AISI
SS 304	S30400	1.4301	X5CrNi18-10	SUS 304	AISI 304
SS 304L	S30403	1.4307	X2CrNi18-9	SUS 304L	AISI 304L
SS 316	S31600	1.4401	X5CrNiMo17-12-2	SUS 316	AISI 316
SS 316L	S31603	1.4404	X2CrNiMo17-12-2	SUS 316L	AISI 316L
SS 316Ti	S31635	1.4571	X6CrNiMoTi17-12-2	SUS 316Ti	AISI 316Ti
SS 321	S32100	1.4541	X6CrNiTi18-10	SUS 321	AISI 321
SS 2205 Duplex	S32205	1.4462	X2CrNiMoN22-5-3	SUS 329J3L	—
SS 904L	N08904	1.4539	X1NiCrMoCuN25-20-5	SUS 890L	—
SS 17-4PH	S17400	1.4542	X5CrNiCuNb16-4	SUS 630	AISI 630

Product Types and Variants

Type	Description	Key Applications
Butterfly Valve Discs	Wafer, lug, double/triple offset DN25-DN600	Process valves, water, HVAC, food, pharmaceutical
Check Valve Discs / Poppets	Swing, lift, dual-plate, wafer check discs	Pipeline, API 594, water treatment, power
Valve Seat Discs	Lapped precision seats, hard-faced rings	Globe, gate, needle, ball valve OEM supply
Pressure Diaphragms	Flat, corrugated, capsule sensing	Pressure transmitters, gauges, regulators
DP Diaphragms	Differential pressure capsule diaphragms	DP transmitters, flow computers, level gauges
Orifice Plates	ISO 5167 sharp-edge and quadrant-edge	Flow metering, custody transfer, AGA-3
Pump Diaphragm Membranes	Corrugated metallic pump diaphragms	Metering, dosing, aseptic, HP process pumps
Diaphragm Valve Membranes	Weir-type and straight-way pads	Pharma, biotech, food diaphragm valves
Restriction Orifice Discs	Single/multiple restriction orifice stacks	Pressure let-down, flow balancing

Industry Applications

Industry	Application
Valve Manufacturers (OEM)	Butterfly discs, check poppets, seat discs, gate wedges, needle valve seats
Instrumentation OEM	Pressure sensing diaphragms, DP capsule diaphragms, orifice flow elements
Oil and Gas / Pipeline	Check valve discs (API 594), orifice plates (ISO 5167/AGA-3), restriction orifices
Power Generation	Steam valve discs, condensate check discs, feed water orifice plates, turbine valve seats
Pharmaceutical / Biotech	Diaphragm valve membranes (USP Class VI), aseptic pump diaphragms, electropolished discs
Chemical / Petrochemical	SS 2205/904L valve discs for chloride/acid service, chemical pump diaphragms
Food and Beverage	3-A compliant diaphragm membranes, SS 316L check discs, CIP valve seat discs
Water Treatment	Butterfly valve discs for water valves, check discs, flow orifice plates

Manufacturing Process

Raw SS coil and sheet are received with EN 10204 3.1 MTCs and slit to required strip widths. Fine blanking presses apply V-ring clamping and counter-punch pressure before blanking to produce perpendicular shear edges. CNC turning centres machine bore diameters, face grooves, and shaft keyways on butterfly discs and valve seat rings requiring machined features. Lapping of valve seat faces is performed on precision lapping machines to achieve 0.001 mm flatness. Corrugated diaphragms are formed on hydraulic presses with precision-ground corrugation tooling. Post-forming operations include stress relief annealing where specified, passivation per ASTM A967, electropolishing per ASTM B912 for pharmaceutical and food grade components, CMM dimensional inspection, surface Ra measurement, and final visual inspection. Full traceability from finished part batch to originating SS coil heat number MTC is maintained for all production.

Quality Standards and Certifications

ISO 9001:2015 — Quality Management System
API 594 — Check Valves: Flanged, Lug, Wafer and Butt-welding
API 598 — Valve Inspection and Testing
API 602 — Gate, Globe, and Check Valves NPS 4 and Smaller
API 609 — Butterfly Valves: Double Flanged, Lug and Wafer Type
BS EN 12516 — Industrial Valves: Shell Design Strength
ANSI/FCI 70-2 — Control Valve Seat Leakage Classification
ISO 5167 — Measurement of Fluid Flow by Pressure Differential Devices
ASTM A240 / A480 — Stainless Steel Sheet and Strip
EN 10088-2 — European SS Flat Products
ASTM A967 — Chemical Passivation of Stainless Steel
ASTM B912 — Electropolishing of Stainless Steel
USP Class VI — Pharmaceutical biocompatibility
FDA 21 CFR — Food contact and pharmaceutical compliance
3-A Sanitary Standards — Dairy and food equipment
EN 10204 3.1 — Mill Test Certificates

Why Choose Stainless Steel Fittings India

Widest SS grade range: 304, 316, 316L, 316Ti, 321, 2205 Duplex, 904L, 17-4PH — matching any valve or process fluid requirement
Fine blanking capability: ±0.01 mm bore tolerance, perpendicular shear edges, eliminating secondary turning for most valve disc sizes
In-house lapping: seat faces to 0.001 mm flatness for ANSI/FCI 70-2 Class V–VI metal-seat shutoff
ISO 5167 orifice plates: bore ground and lapped, face flatness certified, calibration certificates available
Pharmaceutical-grade: electropolished Ra < 0.4 μm, USP Class VI and FDA 21 CFR compliant
PPAP, FAI, CMM reports, EN 10204 3.1 MTCs — complete OEM documentation package
Competitive pricing from US$ 11.60/kg; volume OEM and blanket order discounts
25+ years export experience to USA, UK, UAE, Germany, Australia, Singapore, Canada, South Korea

Frequently Asked Questions

What SS grade is best for butterfly valve discs in chloride service?

SS 2205 Duplex (1.4462) with PREN > 35 is preferred for butterfly valve discs in chloride-containing service — seawater, brine, desalination, and coastal water — due to superior resistance to chloride stress corrosion cracking versus SS 316L. SS 316L is acceptable for low-to-moderate chloride concentrations; 2205 Duplex for aggressive chloride environments exceeding SS 316L resistance.

What bore tolerance is achievable on orifice plates?

After fine blanking, CNC grinding, and lapping, bore diameter tolerance of ±0.01 mm (10 microns) is achieved, meeting ISO 5167-2 requirements of ±0.05% of bore diameter for all standard orifice bore sizes above 20 mm. Calibration measurement certificates confirm bore diameter and face flatness compliance for custody transfer applications.

Can you supply check valve discs to API 594?

Yes. SS 316L and SS 316 check valve discs for swing, dual-plate, and wafer check valves are manufactured to API 594 dimensional requirements with EN 10204 3.1 MTCs confirming chemical composition and mechanical property compliance per API 594 Section 7 material requirements.

What is the thinnest diaphragm you can manufacture?

The minimum thickness for metallic diaphragms in our production range is 0.05 mm (50 microns) in SS 316L. Ultra-thin diaphragms below 0.1 mm require specialised handling and forming to maintain dimensional stability. Prototype evaluation is recommended before production tooling commitment for diaphragms below 0.2 mm thickness.

Are pharmaceutical diaphragm valve membranes available in USP Class VI?

Yes. SS 316L diaphragm valve membranes with electropolished surfaces (Ra < 0.4 μm) and passivation per ASTM A967 meet USP Class VI biocompatibility and FDA 21 CFR food contact requirements. No chlorinated cutting oils or carbon steel tooling contact during manufacture. Compliance certificates are available with each production batch.

Do you supply PPAP documentation for valve OEM customers?

Yes. PPAP Level 1 through Level 3 packages including dimensional inspection reports, material certifications, process capability studies (Cpk), and FMEA are available for automotive and industrial valve OEM customers with volume qualification requirements.

What is the tooling lead time for a new valve disc design?

Simple blanked valve disc tooling: 2–3 weeks. Fine blanking tooling for precision discs: 4–6 weeks. Corrugated diaphragm tooling: 4–8 weeks depending on complexity. Prototype soft tooling for sampling is available in 2–3 weeks for dimensional verification before full production tooling commitment.

Can you manufacture from Hastelloy or Inconel for extreme corrosion service?

Yes. Valve discs and diaphragms from Hastelloy C276 (N10276), Inconel 625 (N06625), Monel 400, and Titanium Grade 2 are available for extreme corrosion service on enquiry. These superalloy grades require specialised tooling and processing parameters and are produced within our sheet metal forming capability with extended lead times.

How is face flatness verified on lapped valve seat discs?

Valve seat disc face flatness is measured on a CMM and verified against a certified optical flat using electronic height gauges. Flatness within 0.001 mm (1 micron) per 100 mm is confirmed and recorded on dimensional inspection reports supplied with each production batch. For critical Class VI metal-seat applications, 100% inspection of face flatness is performed.

What secondary operations are available after fine blanking?

In-house secondary operations include CNC turning, grinding, lapping, CNC punching of shaft holes, coining of hinge features, TIG welding for multi-part assemblies, passivation, electropolishing, laser marking, and mechanical assembly. These allow supply of complete valve disc assemblies — disc plus hinge pin, shaft, or spring — rather than loose disc blanks.

Equivalent Terms in Other Languages

Spanish: Disco de válvula en acero inoxidable, Diafragma de acero inoxidable, Placa de orificio inox, Disco obturador válvula inox
Russian: Диск клапана нержавеющий, Диафрагма из нержавеющей стали, Дроссельная шайба нержавейка, Тарелка клапана нержавеющая
French: Disque de vanne en acier inoxydable, Diaphragme en inox, Plaque à orifice inoxydable, Siège de vanne inox
Portuguese: Disco de válvula em aço inox, Diafragma em aço inoxidável, Placa de orifício inox, Assento de válvula inoxidável
Italian: Disco valvola in acciaio inox, Diaframma inossidabile, Piastra di orifizio inox, Sede valvola in acciaio inox

Explore Our Full Range of Stainless Steel Pressed and Stamped Parts

Request a Quote for Stainless Steel Valve Discs and Diaphragms

Send your valve disc drawings, diaphragm specifications, or orifice plate data to Stainless Steel Fittings India for a competitive quotation. Price from US$ 11.60/kg. All SS grades available including 2205 Duplex and 904L. Fine blanking, precision grinding, lapping, and electropolishing in-house. PPAP, FAI, EN 10204 3.1 documentation. OEM valve manufacturers, instrumentation companies, and EPC contractors from USA, UK, UAE, Germany, Australia, and Southeast Asia are welcome. Contact us for a fast competitive quotation.