Double Offset, High Performance , High Pressure, High Temperature, Zero Leakage Butterfly Valves
[B] BLOW-OUT PROOF STEM: A retaining ring is installed between the machined stem groove and gland retainer step.
[C] ADJUSTABLE STEM PACKING: The stem packing system features easy access to adjusting hex head nuts without requiring removal of the actuator. The system consists of a gland ring, a gland retainer, studs, hex head nuts and lock washers. A 1/4 turn of the hex head nuts is usually all that is required should field adjustment ever be needed. Both hex head nuts must be evenly adjusted and not overtightened.
[D] STEM SEAL: The stem seal system provides constant compression for a positive seal around the stem. PTFE packing seals the stem and a carbon fiber anti–extrusion ring contains the packing. Flexible graphite rings are available for high temperature applications and are standard on fire safe valves.
[E] STEM BEARINGS: Top and bottom bearings, consisting of a 316 Stainless Steel shell with a TFE/glass fabric liner bearing surface securely support the stem. The stem bearings provide excellent resistance to corrosion and distortion from high temperatures and mechanical loading forces.
[F] TAPER PINS: Taper pins are precision fit into reamed holes.
[G] DISC: The disc has been engineered to maximize flow and minimize resistance providing a high Cv. Stainless Steel is standard.
[H] INTERNAL TRAVEL STOP: Designed to prevent travel of the disc and minimizing possible seat damage, therefore extending the service life of the seat.
[I] RESILIENT SEAT: Energizer encapsulated in RTFE
[J] FULL-FACED SEAT RETAINER: Retainer is firmly attached by bolts located outside of sealing area, protecting the bolts from corrosion.
[K] BODY: All body styles offer bi-directional sealing as standard to full ASME Class 150, 300 or 600 ratings. Extended neck allows for 2″ of pipeline insulation and easy access to stem packing adjustments and actuator mounting
Source: High Performance Butterfly Valve – Bray/McCannalok: Double Offset Series 40/41
