The Selection Principle Of The Globe Valve
The stem axis of the globe valve is perpendicular to the seating seal surface, valve stem opening or closing stroke is relatively short, the valve disc once in the open condition, its valve seat and disc sealing surface between the no longer contact, and has a very reliable cutting action, making the cut-off valve products suitable as a medium for cutting or regulating and throttling use. Once the cut-off valve is in the open state, globe valve the valve seat and disc sealing surface between the no longer contact, so the cut-off valve sealing surface mechanical wear less. Since most of the valve seats and discs are easier to repair or replace the seals without having to remove the entire valve from the pipeline, this is a good fit for the welding of valves and pipelines. The flow direction of the medium through such valves has changed, so the flow resistance of the cut-off valve is higher than that of other valves.
The most obvious advantages of the globe valve are: in the opening and closing process, because the disc in the valve body sealing surface between the friction than the valve smaller, and thus wear-resistant. The cut-off valve opening height is generally only 1/4 the diameter of the seat passage, so it is much smaller than the gate valve. Usually there is only one sealing surface on the valve body and disc, so the manufacturing process is better and convenient for maintenance.
The selection principle of the globe valve is:
1 high temperature, high-pressure medium pipe or device should choose the cut-off valve. such as thermal power plants, nuclear power plants, petrochemical systems, high temperature, high-pressure pipe on the road.
2 cut-off valve used in the pipeline on the road, the flow resistance requirements are lax. Where there is little consideration of pressure loss.
3 small valve can choose needle valve, instrument valve, sampling valve, pressure needle valve and so on.
4 has the flow adjustment or the pressure regulation, but to the adjustment accuracy request is not high, moreover the pipeline diameter is comparatively small, if the nominal path ≤50mm the Tube Road, may choose the cut-off valve.
5 The small chemical fertilizer and the big chemical fertilizer in the synthesis industrial production should choose the nominal pressure PN160 nominal pressure 16MPa or PN320 nominal pressure 32MPa high pressure angle type cut-off valve or the high-pressure angle type throttle valve.
6 alumina Bayer Process in the production of silicon removal workshop, easy to coking of the pipeline, easy to choose the valve body separate, seat can be removed, cemented carbide sealing pair of DC-type globe valve or DC-type throttle valve.
7 in the urban construction of water supply, heating engineering, the nominal path of the smaller pipeline, you can choose the cut-off valve, balance valve or plunger valve, such as the nominal flow of less than 150mm pipe.