About thermal oil system valve selection

heat transfer oil is a Heat transfer medium, because of its uniform heating, temperature control temperature accurate, low vapor pressure can produce high temperature (200-400 ℃), good heat transfer, energy saving, transportation and easy operation , Is widely used in various industries. Taking into account its low pressure, high temperature and permeability characteristics of particularly strong, in accordance with the standard technical design specifications, bellows seal valve should be used. Compared with other valves, bellows globe valve is mainly to solve the following problems: 1, because of the permeability of HTF (about 50 times the steam), if the choice of packing globe valve, gate valve or ball valve, are very easy to leak , Resulting in wasted hot oil, dirty equipment and the ground, and the bellows structure can be completely zero leakage, and no wearing parts. 2, because the general filler formed by the graphite processing, if the purity of graphite is not enough, its oil resistance becomes poor, when the thermal conductivity of oil impregnated graphite filler, some impurities in graphite is easily dissolved by the HTF, resulting in graphite powder Shaped, can not achieve the sealing effect of graphite packing, which is the main reason for frequent external leakage of packing valve. 3, because of high temperature, if the choice of universal ball valve, the internal PTFE is not resistant to high temperature, aging quickly lead to valve leakage; and bellows globe valve parts are made of stainless steel, 425 ℃ resistance, the switch is also particularly easy. From the overall life expectancy, the general bellows valve life of more than 3 years. Therefore, in order to ensure the stability of production, but also to reduce the actual operating costs, heat-conducting oil system should be used bellows shut-off valve, can not use filler-sealed globe valve or gate valve.