Double Offset Valves

Double Offset Valves

Double offset valve bodies are available in carbon steel, stainless steel, and nickel aluminum bronze. Discs are available in stainless steel and nickel aluminum bronze. Please inquire for additional materials for specific applications.

Bray McCannalok Double Offset Valves

The Bray/McCannalok high performance double offset valve design provides bidirectional zero-leakage control for hydrocarbons, acids, chemicals, gases, water, and numerous other fluids. The Bray/McCannalok valves are also capable of handling vacuums to 20 microns, and down to 1 micron for special orders. For on-off steam applications, the double offset valve is rated to 150 psi and 366° F, and for modulating applications the rating is 50 psi at 300° F.

Double Offset Valve Cut-out View

Bray/McCannalok Double Offset Valve Cut-out View

(A) STEM - The one-piece stem is constructed of high-strength 17-4 PH stainless steel and is interchangeable among Bray actuators.

(B) BLOW-OUT PROOF STEM - A retaining ring is installed between the machined stem groove and gland retainer step.

(C) ADJUSTABLE STEM PACKING - The packing system has a gland ring, gland retainer, studs, hex head nuts, and lock washers. The hex head nuts can be adjusted without removing the actuator. Field adjustments - if needed - usually only require a quarter-turn of the hex heads.

(D) STEM SEAL - A carbon fiber anti–extrusion ring contains the packing, while the PTFE packing seals the stem. The stem seals retain a constant compression around the stem. High temperature and fire safe valves use flexible graphite rings.

(E) STEM BEARINGS - Stem bearings have high resistance to corrosion and distortion from mechanical loading forces and high temperatures. The top and bottom bearings are of a 316 stainless steel shell and a TFE/glass fabric liner bearing surface that securely supports the stem.

(F) TAPER PINS - The taper pins are precision fit into reamed holes.

(G) DISC - The stainless steel disc maximizes flow while minimizing resistance to give a high Cv.

(H) INTERNAL OVER-TRAVEL STOP - The service life of the seat is extended by minimizing possible seat damage.

(I) RESILIENT SEAT - The energizer is encapsulated in RTFE.

(J) FULL-FACED SEAT RETAINER - The seat retainer is attached by external bolts, thus protecting the bolts from corrosion.

(K) BODY - The extended neck provides for 2" of pipeline insulation while also giving easy access to actuator mounting and stem packing adjustments. All body styles offer bidirectional sealing as standard to full ASME Class 150, 300 or 600 ratings.

Bray/McCannalok Double Offset Valve

The Bray/McCannalok double offset valve's design reduces seat wear while providing full pressure bidirectional zero-leakage shut-off.

Double Offset Valve Disc Action

When the valve enters into the opening cycle, the offset disc utilizes a cam–like action that pulls the disc from the seat which reduces seat wear while eliminating seat deformation when the disc is in the open position. Seat life is increased by the disc not touching the seal while in the open position, and thus operating torque is also decreased. When closing the valve, the cam-like motion creates a linear movement which effectively pushes the disc onto the seat. Material build-up is reduced by the wiping action of the disc and seat.

Bray/McCannalok Double Offset Valve

Bray/McCannalok valves offer a wide range of applications including acids, alkalis, corrosive chemicals, gases, hydrocarbons, water, and many others.

Bray/McCannalok Double Offset Valve

With the decreased torque requirements, the Bray/McCannalok butterfly valves enable the use of smaller actuators. The Bray/McCannalok double offset valve offers efficiency, economy, and proven superior performance for high pressure applications.

Bray/McCannalok Double Offset Valve Seats

The two-part seat assembly has a resilient energizer which is fully encapsulated by the seat. A full-faced seat retainer locks the assembly into the body recess.

Bray/McCannalok Double Offset Valve

Among the numerous advantages of the Bray/McCannalok double offset valve:

1 - The seat retainer and body recess serrations keep the seat assembly in place regardless of the disc's position.

2 - The line's media is bidirectionally sealed to zero-leakage.

3 - The seat itself is energized by line pressure as well as the disc, thus enabling increased sealing during increased pressure.

4 - Complete isolation between line media and the energizer.

5 - The seat self-adjusts for temperature and wear changes.

6 - Fast and easy seat replacement.

Bray International Inc. Valves

Bray International Inc.

Call us at 1-800-999-9308 or visit the Bray International website for more information.