Valve Installation & Maintenance Guide: Best Practices

Q: What is the correct bolt tightening method for a flanged valve?

Tighten the bolts in a criss-cross (star) pattern in several passes, never one side fully first. Work from the center outward, gradually increasing torque on each pass until the flange faces are evenly compressed. This prevents gasket damage and uneven loading.

Q: Should a valve be installed fully open or closed?

For most quarter-turn valves (ball, butterfly) install them in the position that best suits the piping and actuator. For globe and gate valves, install them fully closed to protect the seat while the system is being flushed or commissioned. Never install a valve with its stem pointing straight down in service that could trap debris.

Q: Why does a new valve leak at the flange joint?

The most common cause is improper gasket selection or uneven bolt tightening. Check that the gasket matches the flange face type (RF/FF/RTJ), the faces are clean and aligned, and the bolts are tightened evenly in a star pattern to the correct torque.

Q: How often should industrial valves be maintained?

It depends on service severity. Critical and throttling valves should be inspected periodically (e.g. every 6–12 months), while on/off valves in clean service may only need an annual check. Always follow a preventive maintenance schedule based on the media, duty cycle and operating conditions.

By Jingye Valve Technical Team | Updated August 2026 | Reading time: 9 min

Even a high-quality valve fails early if it is installed or maintained incorrectly. Most field problems — leaks, sticking stems, and premature seat wear — trace back to poor installation and a lack of routine care. This guide covers the best practices that protect your investment and keep valves reliable for years.

1. Handling and storage before installation

Keep valves in their original packaging, protected from dirt, moisture and impact until installation.
Keep protective end caps on to prevent debris and moisture entering the body.
Store on level supports, and protect seats and seals from dust and temperature extremes.
Before installing, check the valve for any transport damage and confirm the rating and material match your order.

2. Pipe preparation

Clean pipe ends thoroughly and remove scale, welding slag, swarf and burrs. Blow out the line before installing valves. Debris left in a pipeline is one of the leading causes of damaged seats and blocked operation. Confirm the pipe ends match the valve connection (flanged, threaded or welded).

3. Flanged valve installation

Align the flange faces parallel and centered, with the gasket correctly placed. Use a criss-cross (star) tightening pattern, increasing torque in several passes so the gasket is compressed evenly. Never fully tighten one bolt before the others, as this distorts the gasket and causes leaks. Use the correct gasket for the face type and service.

4. Threaded and welded connections

For threaded valves, use the correct thread sealant and avoid over-tightening that can crack the body. For welded valves, protect the seat and ball with a shield while welding, and cool slowly to avoid distortion. Always follow the manufacturer’s welding procedure.

5. Commissioning and pressure testing

Flush the system before closing the valves, with valves in the fully open position where possible.
Pressurise slowly and check every joint for leaks before bringing the line to full operating pressure.
Open and close each valve several times to confirm smooth operation.
Verify the flow direction matches the arrow on the valve body (especially check valves).

6. Routine maintenance schedule

Task	Frequency	Purpose
Visual inspection	Monthly / quarterly	Detect leaks, corrosion and loose bolts early
Operate valves through full stroke	Quarterly	Prevent sticking and confirm smooth motion
Check packing / stem seal	As needed	Tighten or replace to stop stem leaks
Lubricate threaded stems	Annual	Reduce wear and operating torque
Full overhaul	Service-dependent	Replace seats, seals and packing

7. Common installation mistakes to avoid

Installing the valve before flushing the line — debris damages seats.
Over-tightening flanges unevenly — distorts the gasket and causes leaks.
Using the valve body to support pipe weight — stresses and cracks the body.
Installing a check valve in the wrong direction.
Skipping the pressure test before putting the line into service.

Frequently Asked Questions

What is the correct bolt tightening method for a flanged valve?

Tighten bolts in a criss-cross pattern in several passes, increasing torque gradually, so the gasket compresses evenly. Never tighten one side fully first.

Should a valve be installed fully open or closed?

For quarter-turn valves, install in the position suiting the piping and actuator. For globe and gate valves, install fully closed during flushing to protect the seat. Check flow direction before commissioning.

Why does a new valve leak at the flange joint?

Usually improper gasket selection or uneven bolt tightening. Check the gasket matches the face type, the faces are clean and aligned, and bolts are tightened evenly in a star pattern.

How often should industrial valves be maintained?

Critical and throttling valves should be inspected every 6–12 months; on/off valves in clean service may only need an annual check. Base the schedule on media, duty and operating conditions.

Need advice on installing or maintaining your valves?

Our engineers can answer technical questions and help you select the right valve and materials for your service conditions.

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