Flanged gate valves provide robust on/off control for critical piping systems across countless industrial applications. However, their unique operating characteristics require some key precautions to ensure safe, reliable performance over the valve’s service life.
Failure to follow proper procedures can lead to hazardous leaks, unintended valve movement, or catastrophic failures with disastrous consequences.
Potential Hazards of Improper Gate Valve Use
While gate valves excel at robust isolation, there are some inherent risk factors to be aware of:
- Trapped Pressure
Gate valve designs feature a cavity between the gate and valve body where process fluid can become trapped. This creates a dangerous buildup of pressure if not properly vented before maintenance.
- Gate Jamming/Binding
Over time, debris, scaling or baked-on solids can cause the gate to stick or bind within the valve body restricting operation. This can prevent tight shutoff and lead to leaks.
- Valve Stem Blowout
The rising valve stem design of gate valves means shut-off forces act directly on the stem. Failing to relieve this force could allow the gate and stem to eject like a projectile when disassembled.
- Installation Misalignment
Improper alignment or uneven gasket loading when installed can quickly deteriorate seat surfaces resulting in fugitive emissions and leaks.
Proper Installation and Operating of Gate Valve
How should the maintenance of the flanged gate valves be carried out? Following some straightforward installation and operating practices can mitigate these potential hazards of flanged gate valves:
- Installation Alignment
Gate valves must be installed with the centerlines of the inlet/outlet and valve bore in perfect alignment. Use precision shims or milled gaskets to avoid cocked/skewed positions.
- Gasket Selection
Always use full circumference gaskets sized to the raised face dimensions per code requirements. Spiral-wound gaskets may be required for high temperatures.
- Torque Procedures
Follow the manufacturer’s specified bolt torquing sequence and values – do not over or under tighten flange hardware. Periodically recheck to maintain proper compression.
- Pressure Relief
NEVER attempt to dismantle a flanged gate valve with trapped pressure in the body cavity. Always provide a venting system with upstream and downstream drain ports.
- Schmierung
Lubricate gate valve stems and stem bushings regularly to prevent binding or galling. The proper lubricant prevents damage and maximizes operating cycles.
- Cycle Testing
Partially opening and then reclosing a gate valve can cause the gate to jam and should be avoided. Only operate fully open or fully closed.
- Gate Protection
Keep the gate in the open position when not providing isolation. Closed gates can incur damage from continuous flow impingement.
Abschluss
Ultimately, sourcing flanged gate valves from a proven manufacturer that adheres to global standards provides the foundation for safe, reliable performance. Premium materials, engineered designs and proper pressure/temperature ratings suited for your application are essential.
For critical applications where the stakes are high, trust the expertise of Xintai-Ventil for your flanged gate valve requirements. Our team will ensure your valve meets all specifications and provide guidance on installation, operation and maintenance for optimum safety and longevity.
