Home / Process

From Ore
to Order

Five disciplined stages. No shortcuts. No deviations. Every VALVAX valve follows the same unbroken chain of accountability — from incoming material to certified dispatch.

01 Material 02 Cast & Forge 03 Machine 04 Test 05 Dispatch
Step 01

Material
Selection

Every valve begins with the selection and verification of its material. We specify only mill-certified alloys with full traceability to the originating heat. Incoming MTCs are cross-referenced against the applicable ASTM, EN, or IS standard before any material is released for production.

Our incoming inspection protocol includes hardness testing, dimensional verification of raw castings or forgings, and visual examination for surface defects. Any discrepancy against the MTC triggers a non-conformance and material is quarantined pending disposition.

Traceability Standard
ASTM A961 / ISO 404 — heat number traced to ladle certificate
Incoming Inspection
PMI (XRF), hardness, visual, dimensional per approved ITP
Rejection Criterion
Any chemistry deviation triggers NCR and immediate quarantine

Standard Material Grades

GradeStandardService
WCBASTM A216General service to 425°C
WC6ASTM A217Alloy steel to 595°C
WC9ASTM A217Mo-alloy to 650°C
CF8MASTM A351SS 316, corrosive service
CF3MASTM A351SS 316L, low carbon
LCCASTM A352Cryogenic to −46°C
DuplexASTM A890Chloride environments
Step 02

Casting &
Forging

The method of forming a valve body is a performance decision, not a cost decision. VALVAX selects the forming method based on the pressure class, wall thickness, service temperature, and NDE requirements of the final application.

All castings undergo full NDE per the applicable standard before machining. Radiography (RT) is performed on Class 900 and above, or wherever specified by the customer. Magnetic particle (MT) or liquid penetrant (PT) examination is applied to machined surfaces on pressure-critical components.

NDE Standard
RT per ASTM E94 / ASME B16.34 Annex B — Class 1 minimum
Acceptance Criteria
ASTM E446 / E186 radiographic quality levels per pressure class

Forming Methods

Sand Casting

Used for large-bore bodies (2″–48″) in Class 150–900. Post-cast heat treatment per material specification. 100% RT for Class 900+.

Class 150–900 2″–48″ RT Class 900+

Investment Casting

Used for complex trim geometries and small-bore bodies requiring superior surface finish. Tighter tolerances than sand casting.

½″–6″ Typical Ra 6.3 μm As-Cast Tight Tolerances

Closed-Die Drop Forging

Used for all Class 800–2500 small-bore valves (½″–2″). Eliminates porosity, aligns grain flow, superior mechanical properties.

Class 800–2500 ½″–2″ API 602
Step 03

CNC
Machining

Machining is where the casting or forging becomes a valve. All bore dimensions, seat profiles, thread forms, and flange faces are produced on 5-axis CNC turning and machining centres. CNC programmes are revision-controlled; no operator improvisation is permitted on critical dimensions.

CMM inspection is integrated into the machining sequence — not only at final inspection. Each critical machined feature is verified before the valve proceeds to the next operation. Seat lapping is performed to optical flatness using traceable equipment.

Bore Tolerance
±0.05 mm on seat bore; ±0.1 mm on body bore to ASME B16.34
Thread Standards
ASME B1.1 (UNC/UNF), ASME B1.20.1 (NPT), ISO 228 (BSP)
Surface Finish
Ra 3.2 μm standard; Ra 0.8 μm seat faces; Ra 1.6 μm flange faces
Flange Faces
RF, RTJ, FF per ASME B16.5 / B16.47; AARH 125–250 serrated finish

Machining Capability

ParameterCapability
Max Bore Diameter1200 mm
Min Bore Diameter8 mm
Bore Tolerance±0.05 mm
Thread AccuracyClass 2A/2B (ASME B1.1)
Surface FinishRa 0.4–6.3 μm
Flatness (flange)0.05 mm / 100 mm
CMM MeasurementIntegrated per operation
Step 04

Assembly &
Test

Assembly is performed in a controlled environment by trained technicians following valve-specific assembly instructions. Torque values for all fasteners are specified on the assembly drawing; torque wrenches are calibrated to national standards.

The API 598 test sequence is non-negotiable. Every valve undergoes shell hydrostatic, seat hydrostatic, and low-pressure pneumatic seat tests. Test pressure, hold time, and leakage criteria are recorded for every valve against its serial number.

Shell Hydrostatic
1.5× MAOP — per API 598 Table 1. Zero visible leakage criterion.
High-Pressure Seat Test
1.1× MAOP — per API 598. Class A/B/C/D leakage per application.
Low-Pressure Pneumatic
80 psi (5.5 bar) air — per API 598. Critical for gas-service valves.
Fugitive Emission Test
ISO 15848-1 type test; ISO 15848-2 production test on FE-rated valves.

Test Parameters — API 598

TestMediumDuration
Shell HydrostaticWater / NaClPer API 598 Table 2
Seat HP HydrostaticWaterPer API 598 Table 2
Seat LP PneumaticAir / N₂Per API 598 Table 2
BackseatWaterPer API 598 Table 2
FE Type TestMethane / HeISO 15848-1 Annex A

Visual Inspection Checklist

Body markings per API 6D / MSS SP-25
Nameplate data vs. purchase order
Flange face finish and dimensions
Painting / coating per specification
Operator direction and flow arrow markings
Step 05

Certify &
Dispatch

No valve leaves VALVAX without a complete documentation package. The Material Data Record (MDR) consolidates material test certificates, NDE reports, dimensional inspection records, hydrostatic and pneumatic test certificates, painting certificates, and final inspection release.

Packing is specified based on valve type, size, pressure class, and shipping conditions. Flange faces are protected with plywood blanks. Threaded connections are capped. Crates are stamped with handling instructions and tagged with purchase order and item numbers.

MTC Standard
EN 10204 Type 3.1 standard; Type 3.2 (third-party witness) on request
Packing Standard
Wooden crates per ISPM 15 (heat treated timber) for all export shipments
Preservation
Rust preventative per 12–18 months outdoor storage specification

Documentation Package

DocumentStandard
Material Test CertificateEN 10204 3.1 / 3.2
Radiographic Test ReportASTM E94 / ASME Sect. V
Dimensional Inspection ReportDrawing / ASME B16.34
Hydrostatic Test CertificateAPI 598
Pneumatic Test CertificateAPI 598
Painting / Coating CertificateCustomer spec / SSPC
Final Inspection ReleaseInternal QMS
Fugitive Emission Cert.ISO 15848 (where required)
Our Philosophy

Zero Defect.
Always.

01

Prevention Over Detection

We do not inspect quality into a valve — we engineer it in. Process controls, poka-yoke fixtures, and revision-controlled procedures prevent defects from occurring. Inspection confirms what the process has already achieved.

02

Traceability Without Exception

Every valve carries a unique serial number traceable to its material heat, machining programme, test records, and inspection data. A valve that cannot be fully traced is not a VALVAX valve. Full material traceability is non-negotiable.

03

Continuous Improvement

Every non-conformance is a learning opportunity. Our corrective action process requires root cause analysis, not just containment. We track failure modes and corrective action effectiveness to drive systematic improvement.

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VALVAX

Our engineering team responds within 24 hours with a tailored recommendation and quote for your application.

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Common Questions

Manufacturing FAQ

What is your standard lead time for industrial valves?

Standard lead time for stock-range valves is 4–6 weeks from purchase order. Custom configurations, special alloys, or large bore valves (above 16″) typically require 8–12 weeks. We maintain buffer stocks of WCB bodies in common sizes to support emergency shutdowns and unplanned replacements.

Which testing standards do VALVAX valves comply with?

All VALVAX valves are tested to API 598 as standard — covering hydrostatic shell tests at 1.5× MAWP and seat closure tests at 1.1× design pressure. We also offer pneumatic low-pressure closure testing, fugitive emissions testing to ISO 15848-1, and full witnessed inspection by third-party agencies including Bureau Veritas, Lloyd's Register, and SGS.

Can you supply valves with full IBR certification?

Yes. VALVAX is an IBR-approved manufacturer. We supply gate, globe, and check valves with IBR Form III-A certification for power plant boiler feedwater and steam applications. IBR documentation is compiled into the Material Data Record (MDR) pack delivered with every valve and is available for third-party review prior to dispatch.

What traceability documentation is provided with each valve?

Every VALVAX valve ships with a complete MDR package including: Mill Test Certificates (MTC) for all pressure-retaining components, dimensional inspection reports, NDE reports (RT / UT / PT / MT as applicable), hydrostatic test certificates, and a heat number traceability chart linking each component to its originating heat. Digital MDR packs in PDF format are available on request.

Do you accommodate witnessed factory acceptance tests (FAT)?

Yes. Client engineers and third-party inspectors are welcome at our facility for witnessed FAT at any stage. We accommodate hold points defined in client-approved Inspection and Test Plans (ITP). Our quality team coordinates inspection scheduling with minimum 72-hour advance notice for routine hold points.

What special service materials and configurations are available?

VALVAX manufactures in Duplex 2205, Super Duplex 2507, Hastelloy C-276, Alloy 20, Inconel 625, titanium, and naval bronze. Special configurations include cryogenic valves with extended bonnets to -196°C, fire-safe designs to API 607 / 6FA, NACE MR0175 sour service preparation, and bellows-sealed stems for zero fugitive emission applications to ISO 15848 Class AH.