DESIGN AND MANUFACTURING CHARACTERISTICS
LUFENG ball valves owns features of valves made in China and in the world, which has realized the perfect combination of new materials, new structure, new technologies. The fixed ball valve is supported by fixed axle (or liner plate) and the stem is of pure torque operation, which eliminates the excessive torque caused when the inlet pressure pushes against the stem. The surface finish of the sphere reaches the mirror surface. The use of metallic bushing lining with good lubrication also ensure small open/close torque, even under maximal operating pressure. The internal parts have been carefully selected to ensures reliable operation under all kinds of service condition. The wall trickness of the valve and the strength of connecting bolt have been strictly calculated and meet the requirements of ASME / ANSI B16.34 standard to ensure the pressure rating and connectiong stability. In addition to the adoption of digital control and machining center for the valve body and all parts and components, the use of CAD design also guarantees high precision, flexibility, and reliable performance of the valve. The valve seat has metallic sealing for primary sealing and non-metallic sealing for secondary sealing. When nominal pressure is at CLASS 600 (10.0MPa) or lower,the VITON-AED non-metallic sealing secondary sealing will be adopted. When nominal pressure is higher than CLASS 600 (10.0MPa), DEVLON, PEEK and all-metal sealing will be adopted.
The main characteristics are as follows:
1,FIREPROOFING STRUCTURE DESIGN:
According to API 607/BS6755 standard, if fire breaks out at the scene of the valve use, the sealing ring made from non-metallic material for secondary sealing may break down or become damaged, the primary metallic sealing would soon come close to the ball for quick sealing. The unique dual sealing valve seat structure design is able to ensure reliable fire protection of the valve seat.
Useing spring and small-ball static electrostatic extractor, together with electrostatic channel formed between the ball and the valve body by the valve stem, the static electricity arising from the friction between the ball and opening/closing of the sealing ring is able to be taken to the ground by the valve body, which effectively eliminates the fore or explosion risk that could possibly be caused by the electrostatic spark.
3,EMERGENCY SEALING SECURITY AND LUBRICATION OF THE VALVE.
If the valve seat and the stem seal become damaged and leakage occurs, instantaneous sealing could be available by filling sealing grease through injection valve. When the valve is under normal operation, the stem and spherical surface may be lubricated by filling lubricant through the injection valve and the valve will be opened and closed more easily.
4,VALVE SEAT STRUCTURE DESIGN :
A.BOTH UPPER AND LOWER STREAM ADOPT SINGLE-PISTON VALVE SEAT:
With the double block/bleed function , it may simultaneously cut off the medium coming from the upper and lower stream; automatic self-relieving function;in case of abnormal pressure rise caused by the medium retained inside the cavity when the temperture rises, the valve seat is able to automatically relieve pressure (discharging towards the low-pressure end).
B.BOTH UPPER AND LOWER STREAM ADOPT DUAL-PISTON VALVE SEAT:
With the double blosck function , it may simultaneously cut off the medium coming from both the upper and lower stream; medium stranded inside the valve cavity is unable to automatic discharge, pressure release valve shall be installed on the valve body to set up pressure in order to release the exceptional pressure rise inside the valve cavity.
C.SINGLE-PISTON SEAT AT UPPER STREAM AND DUAL-PISTON SEAT AT LOWER STREAM :
With the double block/bleed function , it may simultaneously cut off the medium coming from the upper and lower stream; automatic self-relieving function;in case of abnormal pressure rise caused by the medium retained inside the cavity when the temperture rises, the valve seat is able to automatically relieve pressure (discharging towards the upper stream).
5,SETTING THE INSTALLATION PLATFORM OF THE ACTUATING DEVICE:
In accordance with the top flange design on ISO5211, the bracket and adapter sleeve make it easy to install any type of actuating device.
6,EXTENDED VALVE STEM:
For valves with buried installation , according to the installation and operation demand, the valve stem could be extended in accordance with customer requirements for the size of extended stem. All discharge pipe, exhaust pipe, and emergency injection device shall be extended accordingly. Other related pipes shall be close to extended part of the valve for purpose of installing the blow-down valve, air release valve, and grease injection valve above the ground for regular maintenance of the main valve. The suface of the valve shall be coated with anti-corrosion asphalt, polyurethane, or epoxy resin as required to meet the demand of underground service condition.
For valves working in low temperture, the extended valve cover increases the distance between the valve body and the sealing area of the stem, which prevents the impact of temperatrue on sealing performance. Extended height shall be in accordance with relevant standard and customer requirements.
The valve adopts three-piece side-mount structure and sphere is supported by the supporting plate built inside the valve body, which eliminates the excessive torque caused by the huge loading seal when the inlet pressure pushes against the sphere. The surface finish of the sphere reaches the mirror surface; the use of metallic bushing lining with good lubrication also ensures small open/close torque even under maximal operating pressure.
9,FINITE ELEMENT ANALYSIS:
The valve shell and internal elements are designed carefully to make sure they may work reliably under any working conditions, finite element analysis has been adopted to conduct simulated condition analysis for valve shell strength , stress of internal elements, and operating torques of the stem, improve fragile and weak parts, and ensure the superior performance of the valve.