Gate Valve Installation Guide: Avoid Costly Repairs
Publish Time: 2025-03-27 Origin: Site
Gate valves are critical components in pipeline systems. Improper installation or inadequate maintenance leading to valve failure may result in severe damage and costly repairs. Since most gate valves are installed in buried services or underground applications, failures caused by installation errors or poor maintenance often require extensive and expensive excavation operations for effective correction. Therefore, it is essential for users to understand proper gate valve installation procedures.
Pre-Installation Preparation
Receiving Inspection:
Inspect valves for shipping damage upon delivery.
Perform an initial check to verify compliance with specifications (type, size, material, pressure/temperature ratings), opening direction, and end connection type.
Visually examine sealing surfaces for transport-induced damage or scratches.
Inspectors should look for bent stems, damaged handwheels, cracked components, loose bolts, missing parts/accessories, or any evidence of mishandling.
Functional Test:
Cycle each valve through a full open-close operation in its intended installation position.
Report any abnormalities to the supplier or local representative immediately.
Installation Orientation and Positioning
Depending on application requirements, valves can be installed on either horizontal or vertical pipelines. Standard gate valves are typically bidirectional, but special designs or flow direction markings must be followed when specified.
Vertical Installation:
Install valves with stems vertically upward when mounted upright.
Horizontal Installation:
Position stems vertically upward or tilted at a slight angle. Avoid downward orientations to prevent debris ingress and operational difficulties.
Inverted installation is not recommended.
Ensure sufficient clearance for installation, operation, maintenance, inspection, and future replacement.
Image source: istock
Flange Alignment and Securing
During installation, ensure precise alignment between flanges to prevent stress on the valve body.
Use a suitable gasket between the valve flange and mating flange.
Do not install the valve onto flanges until welding is complete and the assembly has cooled to ambient temperature. High welding temperatures can damage elastomeric or rubber valve seats.
Never weld flanges with the valve installed.
Bolting Procedure
Tightening Sequence:
Follow an alternating 180° bolt-tightening sequence to avoid uneven stress on the valve body and flanges.
Step 1: Hand-tighten all bolts initially, alternating diagonally to ensure even contact between flanges.
Step 2: Tighten bolts to 50% of the specified torque using the same alternating pattern.
Step 3: Adjust the torque wrench to the final torque value and tighten all bolts fully.
Verification: Flanges are adequately tightened when their faces are uniformly in contact.
Corrosion Protection:
Properly secure all bolts or fasteners.
Apply anti-corrosion coatings (e.g., paint) or polyethylene wrapping to exposed threads and components.
Critical Reminders
Avoid overtightening, which can warp flanges or crush gaskets.
Confirm alignment with a straightedge or laser tool if precision is critical.
Gate valve tightening sequence
Important Tip:
Before installing flange bolts, lightly coat bolt threads with a high-temperature anti-seize lubricant (e.g., Anti-Gall C-100, #51032, or equivalent).
Severe Warning:
Never insert hands or objects into the valve cavity, as this may cause severe injury or damage to the valve.
Underground Installation Guidelines
Install valves in easily accessible locations for future maintenance.
Place valves on a stable foundation to prevent settling or stress-induced damage.
Install gate valves in the closed position to prevent debris ingress.
Equip underground valves with valve boxes or chambers to isolate them from external loads or stress.
Position valve boxes directly above the operating nut, ensuring the cover is flush with ground level or adjusted per owner specifications.
Use risers or extended keys for valves in deep trenches to ensure operational accessibility.
Install dedicated chambers for valves with gears or actuators to:Maintain clearance around the pipeline.
Allow space for cover removal and maintenance.
Design chambers to address potential groundwater or surface water infiltration and incorporate drainage solutions.
Aboveground & Plant Piping Installation
Ensure valves are properly supported and aligned to avoid damage from pipeline misalignment.
Never use the valve to compensate for pipe misalignment.
Image source: istock
Post-Installation Inspection and Testing
Verify all pressure boundary bolts (valve bonnet, seal plates, gland followers, and end connections) are securely tightened to prevent leaks.
Inspect threaded and plug connections for proper tightness to minimize leakage risks during pressure testing.
Do not backfill excavation areas until post-testing to simplify leak detection.
Conduct hydrostatic testing at a pressure exceeding the system’s design pressure to validate integrity.
Never operate the valve (open/close) under pressures exceeding its rated working pressure, as this may damage sealing surfaces.
Post-installation, record the following details for future reference:
Valve Specifications: Location, size, manufacturer, type.
Installation Data: Date, number of turns to open, opening direction.
Valve Maintenance and Inspection Guide
To ensure long-term and stable valve operation, we recommend performing regular routine inspections with a focus on the following areas:
Inspect areas around the valve stem and flange gaskets for signs of leakage. Over time, seals may degrade due to exposure to air and sunlight. Regular visual inspections can help detect early leaks.
Adjust bolts at flange connections appropriately. Over time, compression of flange gaskets may decrease, leading to potential leaks.
After prolonged use, friction from valve stem movement may cause leaks in the packing area. If this occurs, tighten the packing gland nuts to adjust the seal.
Never replace packing while the valve is pressurized. Performing packing replacement under pipeline pressure is hazardous and strictly prohibited if risks exist due to high temperature, high pressure, or chemical exposure.
Thank you for reading this article. We hope you find it helpful. If you are looking for a high-quality gate valve manufacturer, TFW Valve is your ideal choice—we specialize in gate valve manufacturing and have earned global customer trust through exceptional craftsmanship and reliable performance. Should you have any further questions, please feel free to contact us.