Twin Isolation Plug Valve
Main feartures:
Principles of Operation
Serck Audco Twin Isolation Plug Valves feature two separate Protected Pressure Balanced Taper Plugs and a centrally located bleed port, integral with the body. They are designed to give bubble tight shut off on both high and low pressure applications. This is a robust, In-Line Maintainable valve with low maintenance requirements.The valve body is a rigid single piece casting. The blow out proof valve stems are fugitive emissions tested.The separate plugs are retained in the body by separate bolted covers. The design incorporates provision for external maintenance of the individual stem packings.
Pressure Balancing
Pressure balanced plug valves incorporate pressure balanced plugs, as shown in Fig. 2. The drilling and check valve in the top section of the plug allow the line pressure itself to counteract the upwards force, preventing any possibility of taper locking - without the need for frequent sealant injection.
Plug Balancing
All TIPV valves are protected against the possibility of seizure due to taper locking. Taper locking is caused by an imbalance of forces acting on the plug due to line pressure finding its way into the large end of the plug chamber. As shown by the arrows in Fig. 1, the resultant force tends to push the plug upwards, jamming it in its tapered bore. The plug can remain locked even when line pressure is subsequently reduced.In an attempt to combat taper locking, conventional valves utilise the pressure of the plug sealant, acting on the upper face of the plug, to react against the upwards force. This reduces, but does not eliminate, the possibility of taper locking - and requires regular sealant injection to maintain valve freedom.
Emission Control
Industry standards are tightening the requirements on emissions levels permitted from pressurized equipment. TIPV valves are ahead of the game and are designed and tested to meet the most stringent fugitive emission requirements. Our adjustable gland design, combined with high performance graphite stem packing materials, ensures low emissions over extensive temperature and mechanical cycling, even without the use of O-rings or PTFE seals.
關于福斯閥門的更多產品及應用,請關注 http://www.flowservevalve.gongboshi,com