High Pressure Flat Plate Gate Valve

TYPICAL ADVANTAGES

•Negligible Pressure Drop
•Self - Relieving
•Double Block and Bleed performances
•Equalized Bore (as required/operated)
•Possibility of reverse acting and
equalized bore for fail closed operation
•Double seal upstream by piston effect, down-stream with floating obturator
•Superior Seal Per formances (Bubble Tight)
•Suitable for all types of fluids (including abrasive fluids)
•Suitable for ESDV/BDV applications and Pig Traps
•Extremely flexible actuation with or without stem ejection assistance
•Robust Construction
•Full In-Line maintainability
•Fire Safe construction

Stem/Stem seal
The stem is designed with a threaded-in T bar allowing relative motions of the gate under line pressure. The stem seal uses braided graphite gaskets ensure sealing integrity. Stem sealant injection system is achieved through a por t located on the bonnet. In case of leakage through the stem seal it is possible to inject the sealant through the stem packing release valve.

Seat
Seats are ENP coated and are provided with thermoplastic soft inser t on their face.
A "double face seal" effect is obtained due to metallic contact between the seat and the gate, thus increasing the reliability of the valve. Metal-to-metal seating is available for abrasive ser vice. In such case gate and seat faces are coated with HVOF Tungsten Carbide coating.

Fire-safe design
Flanged End Expanding Gate Valves is available in the API 6FA fire-tested design. Fire-tests have been witnessed and cer tified by independent authorities. RAYS Fire tested gate valves offer the highest resistance against fire. The body seal is a spiral wound graphite/AISI 316 gasket and the stem seal is a die-formed/braided graphite packing. The stem incorporates the back seat feature to allow stem seal re-packing with valve in ser vice. Fire-tests cer tification is available and can be provided upon request.

Fully piggable
Flanged End Expanding Gate Valves are designed to be Fully Piggable. Pigs and scrapers can be run through the valve without any damage to the internal structure of the valve.

Easy maintenance
Flanged End Expanding Gate Valves design minimizes and eases the maintenance allowing for the ser vice operations to be done without the removal of the valve from the line.

Double Block and Bleed
Double block and bleed capability and automatic relief of excess body pressure are standard features of RAYS Through Conduit Slab Gate Valves. With the valve fully closed and pressure on both sides, it is possible to bleed the pressure from the body cavity to check seat seal integrity and to achieve double isolation between the two sides and avoid any risk of product contamination

Single piston effect seats
Seats rings are floating type and are energized against the gate by means of helical springs. The initial seating is enough to assure sealing between gate and upstream seat when the line pressure is applied. The gate allows axial movement and the upstream force derived from line pressure force the gate against the downstream seat creating a double, bubble tight barrier.

Additional features (Available on request)
• Metal seated/Tungsten Carbide coating for abrasive fluids
• Stem extension for buried ser vice/high temperature ser vice
• Inconel 625 cladding of the sealing sur faces for corrosive ser vice
• CRA alloys for ver y corrosive media (Duplex,UNS S31254,UNS S34565)
• Seat Sealant Injection system for Emergency Sealing
• Transition Pipe Pups welded to the valve ends
• Position indicator
• Actuation (Electric, Pneumatic and Hydraulic actuators)

Self relieving features
The single piston design with the possibility of both seats and gate to float, permits the automatic release of any overpressure in the body cavity.
Consequently, the seat rings are "self-relieving".