Expanding Gate Valves are manufactured and tested in accordance with the API-6D standard. This type of valve is very suitable for onshore and offshore applications where suspended and abrasive solids are present in the fluid for oil and gas transportation and isolation services, DBB design offers proper seal in between both seats and gates in high and low pressure for this reason line pressure is not needed to seal the valve.
• Design according to the API-6D standard.
• Full and continuous bore for the passage of cleaning tools.
• “Top Entry” design for maintenance on the line.
• Double Block and Purge in open or closed position.
• Uni-directional and bidirectional seats.
• The operation mode varies according customer needs they can be operated by: Handwheel, impact handwheel, chain operators, gear operators or electric, pneumatic or hydraulic actuators.
• Option available in soft seal and with hard coatings of tungsten carbide or stellite for aggressive services through the HVOF process.
• Flanged or fully weldable ends.
• Flanges conforming to the ASME B16.5 standard from 2” to 24”.
• Flanges conforming to the ASME B16.47 series A or B standard for 26” and larger valves.
• Pressure tests according to API 6D.
Applications and Unique Features
Expanding Gate Valves are widely used, particularly in the Midstream Pipeline and Terminal Storage Industry. The Expanding Gate Valve is the best used engineered product for critical applications. Like a Slab Gate the internal pipeline pressure aids in creating a tight seal, but the primary seal is created by the mechanical action of the expanding gate against the floating seats. This provides a higher degree of security in situations where extreme pressure differential is of concern. The Expanding Gate design is often the preferred valve for pigging operations where the gate is the only pressure barrier to the atmosphere.
The unique feature of the Expanding Gate valve is the Double Isolation and Bleed (DIB) function. This provides the ability to vent the body cavity even when there is high pressure on only once side of the valve. DIB is achieved by the mechanical gate to seat contact which provides a positive low pressure seal. The mechanical contact between gate and seats also help prevent debris or solids in the flow-line from entering the body cavity. Low torque manual operation is preferred.