HTF is a heat transfer medium, owing to its uniform heating, thermostat control temperature accurately, can be generated under the low vapor pressure high-temperature (200-400 ℃), heat transfer effect is good, energy saving, transport and easy to operate and so on are widely used in various industries. Taking into account its low-pressure, high temperature and permeability characteristics of particularly strong, according to the standard technical design specifications, should be used bellows sealed stop valve.
Compared with the other valve, bellows globe valve is mainly to resolve the following issues:
1, because the permeability of highly heat-conducting oil (about 50 times the steam), if the choice of filling cut-off valve, gate valve or ball valve, are very easy to leak, resulting in hot oil waste, dirty equipment and floors, and corrugated tube structure can be completely zero leakage, and no wearing parts.
2, because the general process of filling materials from the graphite shape, if the purity of graphite is not enough, its oil resistance becomes poor, when the heat-conducting oil dipped when the graphite packing, graphite in the part of the dissolved impurities can be easily heat-conducting oil, resulting in graphite powder shape-based, can not make up Graphite packing sealing effect, which is caused by filling valves leak outside the main reason for the recurrent.
3, because the high temperature, if the selection of general-purpose ball valves, PTFE does not heat the house, and soon the aging caused by valve leakage; while bellows globe valve internal parts material entirely of stainless steel, can withstand 425 ℃, is particularly easy to switch.， the overall expectancy ordinary life of bellows globe valve in three years. Therefore, in order to ensure the stability of production, but also in order to reduce the actual running costs, heat-conducting oil system should use bellows globe valve, packing seal can not use the cut-off valves or gate valves.