■The integral valve is an integrated metal hard-sealed ball valve. Such design can realize zero leakage.

　　The scope of application is high pressure and high pressure, including valve switches in electric power, petrochemical and metallurgical industries.

　　■ Size: 0.5"-4.00"

　　■ Pressure rating: 900—4500

　　■Manufacturing standard: ASME B16.34

　　■ Material: A105,F22,F91,F92,316

　　■ Rocket-spraying chrome carbide on the ball and seat

　　■Flow direction indication mark on valve body

　　■ Reducing the maintenance for the stem seal

　　■ Two molded stuffing, two counter-pressed stem stuffing

　　■ Anti-pop design of valve stem

　　■ Downstream pressure in thrust seat

　　■ The disc spring keeps the upstream valve seat at a constant sealing pressure

　　■ The ball and seat are ground in pairs to assure zero leakage when the valve is closed

　　■ ISO standard bracket

　　■ Steel pin—to prevent side load bolt stress

　　■Consult factory for special size

　　The design features of ball valve and seat

　　Each valve manufactured by GRAND guarantees "one-to-one" precision grinding between the ball and the valve seat. Before assembly, each pair of balls and valve seats is subject to mechanical rough grinding and manual "one-to-one" fine grinding. During manual grinding, four kinds of grinding pastes would be used to assure high-density "one-to-one" grinding, and each pair of ballbodies and valve seats would be 100% inspected with a special thickness gauge so that each pair of balls and valve seats can be mutually absorbed after precision grinding to achieve perfect sealing effect (vacuum sealing), which is the key of zero leakage for GRAND valves.

　　The ball bodies and the valve seats would are grinded one to one to achieve mirror sealing. When the valve is working, the ball body and the valve seat sealing area are completely sealed and contacted. The upstream and downstream valve seats can automatically scrape off the media on the surface of the ball body when the valve switch is operating,and clean the surface of the ball body to ensure zero leakage and stabilize torque of the valve. The GRAND ball valve has a large seal face size, which can effectively reduce the stress of the ball on the valve seat. For certain high-frequency valve switching conditions, such design can extend the service life of the seal components.

　　GRAND ball valve has a large seal face size, which can effectively reduce the stress of the ball body on the valve seat. For certain high-frequency valve switching conditions, such design can extend the service life of the seal components.

　　Pre-assembly inspection

　　Prior to assembly, all valve components would be subject to a detailed inspection / test.The test includes:

　　1) Dimensional inspection

　　2) The final thickness and flaw detection of the sprayed coating

　　3) Surface roughness inspection of all internal parts

　　Coating manufacturing process and features

　　GRAND ball valve adopts the leading rocket spraying process (RMA) which is a rocket spraying process with hydrogen as the main fuel. After hydrogen, argon and oxygen are fully combusted and exploded, a flame will emerge with the speed up to 6000 yards/s (three times the sound speed). Through a specially-designed spray gun, metal powder particles are sprayed at high speed on the ball surface and the valve seat sealing surface, thus forming a dense coating with strong adhesion. The normal adhesion strength can reach 70Mpa, and the surface hardness of the coating can reach HRC68-76, preventing from the scratch by the medium and its impurities.So as to reach the perfect combination of hardness and strength. GRAND is equipped witha complete set of Stellite spraying equipment, and has establishedits own spraying room for independent spraying operation, or use Panasonic welding machine arm for independent spraying operation. According to the spraying materials designated by the customer or the actual service conditions, we can select the appropriate spraying materials (chromium carbide, tungsten carbide, Stellite, etc.) to achieve a dense and highly adhesive coating and then to achieve safely and stably the vacuum (mirror) seal between the ball and the valve seat under adverse conditions.