In particular chemical processes the fluids in the pipes are often toxic, radioactive and hazardous. Bellows seal gate valves are used to prevent leakage of any toxic chemical to the atmosphere. Body material can be selected from all available materials,The bellow can be supplied in different materials like 316Ti, 321, C276 or Alloy 625.

• 1).Metal bellows seals the moving stem and increases durability of packed stem seal valves.
• 2).Bellows monitoring port (optional): A plug can be connected with the space above the bellows to monitor performance.
• 3).Two secondary stem seals: a) Backseat in open position; b) Graphite packing.
• 4).for Bellows seal gate valve, its key components metal bellows,the lower end and valve stem are automatic rolling welded,and the upper end and the protection tube are automatic roll welded as well. A metal barrier is formed between the stem at its point of entry through the pressure boundary and the process fluid within the valve,to eliminate stem leakage;
• 5).Bellow-sealed valves are usually leak tested using a mass spectrometer to detect leakage rates below 1x10E-06 std.cc/sec.Double sealing design (bellows seal and stem packing) if the bellows fail, valve stem packing will also avoid leakage,and in conformity with international tightness standards;
• 6).Bellow-sealed bonnets are backed up with a standard stem packing set and a leakage monitoring port between the bellows and the packing in order to prevent catastrophic release of hazardous fluid in the event of a bellows leak.
• 7).Not as the tradtional grease screw only for the stem thread,A grease nipple is designed on the valve bonnet,we may lubricate lubricate the stem,nut and bushing directly,through the grease nipple;
• 8).Ergonomically designed handwheel, longer service life, easy to operate, safer and more reliable;