Quality Control & Testing
Industrial valve performance and operational safety are verified through rigorous inspection, pressure testing, and document traceability. Quality control covers every stage-from raw material verification and precision machining to final pressure integrity and release.
Pressure Boundary & Hydrostatic Shell Testing
Objective:
Detect casting or forging porosity, material defects, and shell leakage.
Procedure:
The valve is placed in a partially open position and filled with liquid (typically clean water with rust inhibitors). Test pressure is applied according to the governing standard.
Acceptance Criteria:
Pressure must be maintained for the required duration without visible leakage, structural deformation, or pressure drop.
Seat Leakage Testing & Standards
|
Standard |
Standard Purpose |
Leakage Classification / Acceptance Basis |
|
API 598 |
Valve Inspection and Testing |
Specifies allowable drops/min or cc/min based on valve size and seat type. |
|
ISO 5208 |
Industrial Valve Pressure Testing |
Categorizes sealing performance from Rate A (zero visible leak) to Rate G. |
|
EN 12266-1 |
Testing of Metallic Valves |
Defines European procedures for pressure testing and leakage rate classes. |
|
API 609 |
Butterfly Valve Design & Testing |
Standard requirements specifically for double and triple-offset butterfly valves. |
|
EN 593 |
Metallic Butterfly Valves |
European industrial specification for butterfly valve testing and performance. |
|
MSS SP-67 |
General Butterfly Valves |
Standard requirements for testing, dimensions, and coatings. |
Technical Inspection & Verification Matrix
|
Inspection Category |
Inspected Parameters |
Primary Verification Goal |
|
Dimensions & Interfaces |
Face-to-face, flange dimensions, bolt-hole circle, stem diameter, ISO 5211 top flange |
Ensures direct alignment, pipe fit-up, and actuator/gearbox compatibility. |
|
Visual & Surface |
Surface finish, coating thickness (DFT), wall thickness, body casting markings |
Verifies structural soundness and identifies defects prior to shipment. |
|
Assembly & Function |
Trim alignment, packing compression, fastener torque, stroke cycle, flow direction |
Guarantees smooth opening/closing cycles and proper operational torque. |
|
Material Traceability |
Positive Material Identification (PMI), EN 10204 3.1 MTC, heat number tracking |
Prevents material mix-ups and ensures compliance in corrosive or high-temp service. |
Quality Control by Application
|
Application Sector |
Key Inspection Focus |
Specialized Testing Options |
|
Water & Wastewater |
Anti-corrosion coating (epoxy DFT), zero seat leakage, operational torque |
Low-pressure air test, coating adhesion |
|
Chemical Processing |
High-alloy material verification (Duplex, Hastelloy), packing integrity |
NACE MR0175 compliance, PTFE/elastomer checks |
|
Oil & Gas (Upstream/Downstream) |
Pressure boundary verification, full heat traceability, API compliance |
Fire-safe (API 607), Fugitive Emission (ISO 15848) |
|
Power & Steam Services |
High-temperature pressure boundary integrity, stellite hardfacing |
Non-Destructive Examination (RT, UT, PT, MT) |
|
Low-Temperature Services |
Material toughness at sub-zero temperatures, extended bonnet dimensions |
Cryogenic testing down to -196 C (BS 6364) |
Quality Documentation & Quality Evidence
To support technical audits and project handovers, each shipment can be supplied with a complete Quality Document Package, including:
EN 10204 3.1 / 3.2 Material Test Certificates (MTC)
Hydrostatic Shell & Seat Leakage Test Reports
Dimensional & Visual Inspection Records
Non-Destructive Examination (NDE / NDT) Reports
Coating Thickness Inspection Logs
Certificate of Conformance (CoC)
Customer-Specified & Third-Party Inspection
Witness & Hold Points:
On-site inspection witnessed by customer quality personnel.
Third-Party Inspection (TPI):
Independent verification by agencies such as SGS, TUV, Bureau Veritas (BV), DNV, or Lloyd's Register.
Custom Testing Profiles:
Extended pressure hold durations, low-pressure gas seat testing, or project-specific tagging and packaging.