A floating ball design offers efficient sealing with simple construction. As the name indicates, the ball has some freedom to move along the axis of the pipeline, which offers efficient downstream sealing. When line pressure is applied to the closed ball, it moves slightly (or floats) downstream to maintain contact with the downstream seat where primary sealing occurs. A quarter turn motion from full open to full close ensures quick open-close action, an inherent advantage for automatic remote control application. Floating ball valve offers effective bidirectional sealing.
Antistatic design feature provided in the valve prevents any accidental fire due to static electric discharge. With the low resistance short circuit path created between the ball and the valve body, any build up of static electric charge on the ball due to constant rubbing within the PTFE seat is prevented. The ball valve is completely conductive between ball and body in which no static electricity may develop - a requirement essential to the treatment of such low flashing point fluids as gasoline, natural liquified gas, propane gas etc.
Valves exposed to the risk of accidental external fire need to have additional secondary metal sealing system to make it fire safe. Special design features are built into the valve to ensure continued sealing performance even after burn out of the soft sealing parts of the valve. A metal seat located on the body comes in direct contact with the ball on burnout of the soft parts ensuring continued sealing. Full range approved as per latest edition.
Aqua Ball Valve have safe blow out proof stem Assembly, which eliminates the possibilities of hazards. With GFT thrust washer the stem is inserted through the valve body cavity and rests against a shoulder machined in the valve body. PTFE / Graphoil gland packings above the shoulder are held in place by a gland which is machined taper to give sealing between stem and packing.
Especially when installed outdoors, to prevent the valve from wrong operations, it is lockable with a pad lock at two points fully closed or open positions. In other words, an operation of the valve is limited to protect it against the possibilities that an outsider may accidentally operate the lever or the valve may be opened or closed due to vibrations, especially when an inflammable petroleum product or chemicals are handled.
Trunnion mounted design offers precise locational accuracy for the ball within the upstream and downstream seat, which ensures leak tight sealing with lower operative torques. The sealing takes place by allowing the seats to move towards the ball. This design ball valves can hold very high pressures.
This is a function for providing seal of fluids by upstream and downstream seats with the valve in close positioned for draining the fluids accumulated in the body cavity. The benefits are : Leaks and damage to the seats are checked in advance. Contamination caused during changing fluid types is minimized, parts of the gland seal can be changed under pressure.
The metal seated ball valves are available in all ranges. Its quality starts with the sphericity of the ball and the surface finish. The ball is of mirror quality finish. This provides outstanding smoothness and roundness, resulting in a prime contribution to low torque and reduced leakage up to Class V. The metal seated ball valves typically can be used for higher temperature ranges & abrasive service.
Above the gland two belleville washers (disc spring) and gland nut are provided. The gland nut allows gland packing adjustment, and disc spring automatically compensates for normal wear as well as seal expansion and contraction from temperature fluctuations. The gland nut is provided below the handle permitted the handle to be removed without disturbing the stem adjustment or causing an unsafe condition.
If the pressure of the fluid the valve body cavity exceeds the line pressure due to thermal expansion of the liquids entrapped in the valve body, seats provide automatic pressure relief, without the aid of the safety or vent valve. During closing of the valve, the maximum surge pressure occurs, during which the downstream seat can be forced to intrude into the ball port and can become inoperative. The pressure relief slots prevent this potential failure. When pressure causes the upstream seat to move against the ball the ball moves downstream, the pressure simply leaks in the ball port through the relief slot.
In Addition to this we also provide
♦ Single-seal and double-seal system.
♦ Sealant injection system can be provided on request.
♦ Ball valves for cryogenic service, oxygen, chlorine service.
♦ Jacketed&V-notch ball valves.
♦ Tungsten Carbide & Chromium Carbide coating is available for ball & seat.