Valves with Protected Bellows Type

Leakage at various points in pipelines found in chemical plants creates emissions. These leakage points can be detected using various methods and instruments and ought to noted by the plant engineer. Critical leakage points include flanged gasket joints and the Valve pump gland packing etc. Today the chemical process publication rack gearing itself towards safer technology for better environmental protection and it has fast become every process engineers responsibility to design plants to limit damage to the environment through the prevention of leakage of any toxic chemicals. Bellows Sealed Gate Valve VALVOLA Bellows Sealed Gate Valve LEAKAGE Contrary to the VALVE GLAND OR STUFFING BOX is normally an issue for the maintenance or plant engineer.

This leakage means a loss of profits of material b Pollution to the atmosphere c Dangerous for plant employees. For example take the case of a steam leakage through the Valve gland. At PSI a clearance of just . through the gland will mean a leak at the rate of lbhour. This equates into a loss of USD . per eight hour shift or USD each and every year. Similarly a tiny drop of .

mm diameter per second results in a waste of about litres every single year of costly oil or solvent. This leakage could be reduced considerably by while using bellow seal Valve. The following paragraphs will now consider the construction and operation of the bellow seal. BELLOW CONSTRUCTION The bellow cartridge is welded to both the Valve Bonnet and the Valve stem. The bellow cartridge has an associated with convolutions and these convolutions become compressed or expanded depending upon the movement of Valve stem. Scientifically speaking the bellow gets compressed when the Valve is in the open position and expanded once the Valve is in the closed condition.

It is important appropriately install the Valve bodies. The bellow can be sealed to the Valves in two methods. Firstly the bellow can be welded to the Valve stem at the top along with the Valve body on the bottom. In this case the process fluid is contained inside the bellow or in second method the bellow is welded to the Valve stem at the bottom and the body simple. In this case the process fluid is contained on the annular region between the Valve Bonnet and bellow from the outside.