Land Subsoiler,Farm Subsoiler,Subsoil Cultivator,Agricultural Subsoiler JINING TIANDE ENGINEERING MACHINERY CO.,LTD , https://www.tdgoldargo.com
Long-distance pipeline ball valve technical performance
The actual working conditions of the long-distance pipeline are in a harsh environment. They are installed from the Arctic Circle to the equator, from high mountains to the sea bottom, from plateau to desert, through seismic belts, swamps, permafrost, rivers, lakes and slopes Some buried underground, operating in the field, maintenance difficulties, requiring 30 years of service life. Long-distance pipeline general transmission medium for crude oil and natural gas, although the media contains sulfide, impurities and foreign bodies, and requires zero-level seal. Therefore, the pipeline ball valve made a strict technical requirements. (1) Strength and Toughness In addition to the internal media pressure, the valve still needs to withstand axial tension and pressure due to changes in ambient temperature. Considering the landslide, land subsidence and flood caused by external loads, cold and frozen areas need to consider the low temperature impact toughness, to prevent low temperature brittle fracture. For all-welded valve ball valve, weld and heat-affected zone, fracture mechanics in accordance with the need to consider the fracture toughness. (2) Zero-stage sealing valves require a zero-stage seal to ensure effective shut-off of the downstream end of the line. Consider the effect of metal particles on zero-level seals in media, metal-to-metal seals as primary seals, PTFE / rubber-to-metal secondary seals, and emergency sealing in the event of seal failure. (3) fire safety and anti-static pipeline ball valve design must consider the fire safety. In the event of fire, valve leakage and internal leakage shall not exceed API 607 ​​specified leakage criteria. The ball is clamped by a non-metallic material and may generate static electricity that must be conductive to the valve body. At 24 VDC, the resistance is <10 Ω. (4) Double Brock & Bleed When the valve chamber is drained, the upstream and downstream valve seats should also be cut off automatically to ensure safety during discharge. (5) to prevent the valve cavity pressure clamping Whether the valve is open or closed position, should prevent the medium in the valve cavity is clamped. If the media may be clipped. Then for gas or liquid media, ensure that the pressure in the auto-vent valve cavity is at a maximum of 1133 times the pressure relief of the valve cavity and DN 15 or greater of the external pressure relief valve. (6) Exhaust valve cavity media can be drained, and through the drain hole on-line valve sealing test. (7) Position indication Whether manual or powered, there should be a clear indication of the valve position, indicating that the valve is open or closed. (8) Transmission chain drive chain design torque should be at least 2 times the maximum torque of the ball valve. (9) Vulcanization conditions The pressure-bearing components and bolt materials shall have the capability of resistance to stress cracking and shall meet the requirements of NACE MR0175. (10) Emergency cutoff The long-distance pipeline conveying system adopts the satellite monitoring system. When the rate or duration of pipeline pressure drop reaches a certain set value, the valve should be cut off urgently. (11) anti-corrosion All-welded valve body structure, the pipeline cathode and the outer surface of the anti-corrosion, prevent groundwater potential corrosion and stress corrosion.