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Check Valve Manufacturer in Germany

Author : Valvesonly Europe | Published On : 15 Jul 2026

 

The piping network used in industries relies upon check valves which are needed to avoid backflow and to ensure protection for pumps, compressors, and other processing equipment against any pressure changes. Before the installation of the check valve, there is a need for carrying out a number of tests to ascertain that the check valve has met the requirements of the design and international standards. All Check valve manufacturer in Germany follow certain inspection criteria as per API, ASME, DIN, EN, and ISO standards.

Why Testing and Inspection Matter

The check valve is designed to operate automatically without the use of any external force, which makes internal element performance very crucial. Any manufacturing defect, improper seating, or dimensional problems can cause leaks, pressure drops, vibration, or even premature wearing out.

Performance tests prove the following features:

  • Pressure containment capability

  • Seat tightness

  • Disc movement

  • Reverse flow prevention

  • Material integrity

  • Structural strength

  • Dimensional accuracy

These inspections help ensure the valve performs according to its specified pressure class and service conditions.

Material Inspection Before Manufacturing

Testing begins long before the valve is assembled. Raw materials are inspected to confirm compliance with project specifications.

Common verification procedures include:

  • Positive Material Identification (PMI)

  • Chemical composition analysis

  • Mechanical property testing

  • Tensile strength verification

  • Hardness testing

  • Impact testing for low-temperature service

Materials such as Carbon Steel, Stainless Steel, Duplex Stainless Steel, Alloy Steel, and Nickel Alloys are checked against ASTM or EN material standards before machining.

Dimensional Inspection

Every machined component undergoes dimensional inspection using calibrated measuring instruments.

Parameters include:

  • Face to face dimensions

  • Flange drilling dimensions

  • Wall thickness

  • Disc alignment

  • Seat dimensions

  • Bore diameter

  • Stem guide clearance

These measurements verify compliance with standards such as ASME B16.10, ASME B16.5, EN 558, and DIN specifications.

Hydrostatic Shell Test

The shell test evaluates the structural integrity of the valve body and bonnet under pressure.

During this test:

  • The valve body is filled with water.

  • Pressure is applied above the design operating pressure.

  • The body is inspected for leakage.

  • Permanent deformation is checked.

Most industrial check valves are tested according to API 598 or EN 12266-1 requirements. The valve body must remain leak-free throughout the specified holding period.

Seat Leakage Test

Seat leakage testing verifies that reverse flow is effectively blocked when the valve closes.

Testing may use:

  • Water

  • Air

  • Nitrogen

Inspection focuses on:

  • Seat sealing

  • Disc seating

  • Leakage rate

  • Bubble formation during pneumatic testing

Acceptance criteria depend on valve type, pressure class, and customer specifications.

Functional Testing

Functional testing confirms that internal moving parts operate smoothly.

Engineers evaluate:

  • Disc opening angle

  • Disc closing speed

  • Spring compression (for spring-loaded designs)

  • Swing arm movement

  • Lift mechanism performance

The valve must open with the specified cracking pressure while closing quickly enough to minimize reverse flow and water hammer.

Non-Destructive Testing (NDT)

Many industrial applications require additional inspection using Non-Destructive Testing methods.

Common NDT techniques include:

  • Radiographic Testing (RT)

  • Ultrasonic Testing (UT)

  • Magnetic Particle Inspection (MPI)

  • Dye Penetrant Testing (PT)

  • Visual Inspection (VT)

These methods identify casting defects, cracks, inclusions, porosity, and weld imperfections without damaging the valve.

Pressure and Performance Testing

Performance testing verifies operation under simulated service conditions.

Engineers monitor:

  • Cracking pressure

  • Maximum working pressure

  • Pressure loss across the valve

  • Disc stability

  • Flow characteristics

  • Closing response

These tests help determine whether the valve meets the required process conditions.

Standards Used for Inspection

Industrial check valves are commonly inspected according to internationally recognized standards, including:

  • API 598 - Valve Inspection and Testing

  • API 594 - Check Valve Design

  • ASME B16.34 - Pressure-Temperature Ratings

  • EN 12266-1 - Industrial Valve Testing

  • ISO 5208 - Pressure Testing

  • MSS SP-61 - Pressure Testing of Steel Valves

Compliance with these standards ensures consistent testing procedures across production batches.

Documentation and Quality Records

After testing, manufacturers prepare inspection documentation that accompanies the supplied valve.

Typical documents include:

  • Hydrostatic test report

  • Material Test Certificate (EN 10204 3.1)

  • Dimensional inspection report

  • NDT reports

  • Pressure test records

  • Heat treatment certificates

  • Calibration records

These documents provide traceability throughout the manufacturing process.

Final Inspection Before Dispatch

Before shipment, every valve undergoes a final quality inspection.

The inspection covers:

  • Surface finish

  • Protective coating

  • Flange protection

  • Nameplate verification

  • Marking accuracy

  • Packing and preservation

  • Documentation review

Only valves that successfully complete all inspection stages are released for delivery.

Inspection and Testing Standards 

Inspection and testing ensure the quality of industrial check valves as far as pressure containment, leakage levels, dimensions, material requirements, and performance are concerned before putting them into use. Tests like hydrostatic test, seat leakage test, functionality test, and non-destructive test ensure conformity to various international standards like API 598, API 594, ISO 5208, and EN 12266-1. Choosing a Check Valve Manufacturer in Germany that has complete documentation of its inspection and testing practices helps in ensuring performance consistency of valves in industry.

Visit us: https://www.valvesonlyeurope.com/product-category/check-valve/