Valve Pressure Testing: A Complete Guide to Pressure Valve Testing, Safety Valve Inspection, and Testing Procedures

This procedure helps identify damaged seats, worn sealing surfaces, and other defects that may affect shut-off performance.

3. Backseat Test

Some gate and globe valves include a backseat feature that helps prevent leakage around the stem when the valve is fully open.

When applicable, a backseat test checks the sealing performance of this feature under the conditions specified by the manufacturer or governing standard.

Not every valve includes a backseat, so this test is only relevant to suitable designs.

4. Functional and Operational Test

A functional test checks whether the valve opens, closes, and operates as intended. Depending on the design, inspectors may examine the handwheel, actuator, stem movement, and operating mechanism.

This test can reveal sticking, excessive operating force, incorrect movement, or other mechanical problems that may not be identified by a pressure test alone.

Pressure Safety Valve Testing: Why It Matters

Pressure safety valves protect equipment and systems against excessive pressure. When pressure rises above the permitted limit, the valve is designed to open and release pressure according to its specified operating characteristics.

Pressure safety valve testing helps verify that the valve operates within its required performance limits.

Common checks include:

• Inspection of the valve body, connections, and visible components.
• Verification of the specified set pressure.
• Examination of opening and closing behavior.
• Checking for leakage where applicable.
• Inspection of the spring, adjustment mechanism, and sealing components.
• Verification of test results against the required acceptance criteria.

Testing may involve a suitable calibrated test bench or an approved in-service testing method. The correct approach depends on the valve design, service conditions, and applicable requirements.

A pressure safety valve should not be adjusted or tested using improvised methods. Incorrect testing can affect its calibration and compromise the protection it provides.

Valve Inspection and Testing: Step-by-Step Procedure

A structured inspection process helps technicians identify defects and maintain consistent testing records.

Step 1: Review Specifications

Before testing begins, inspectors review the purchase order, drawings, valve data sheet, pressure rating, material requirements, and applicable standards.

This step confirms which tests are required and establishes the correct acceptance criteria.

Step 2: Perform a Visual Inspection

The inspector examines the valve for cracks, corrosion, damaged threads, loose components, surface defects, and other visible problems.

The valve identification, size, model, and rating should also be checked against the approved documentation.

Step 3: Prepare the Test Equipment