Fixed ball valve door main structural characteristics and operation
Fixed ball valve door adopt the valve rod fixed valve core (up and down Shaft type) And movable seal seat design. Work is more stable. With automatic compensation function, double seal between the valve seat without clearance rotary has a great deal of the shear force and self-cleaning function. Especially suitable for imperial fiber and has a small solid particles suspension and viscous medium on and off. Fixed ball valve door products can be widely used in papermaking, petrochemical, chemical, metallurgy, electric power, environmental protection, petroleum, light industry and other industrial departments of automation control system. Fixed ball valve door structure characteristics: 1, blocking and excretion: fixed ball valve door adopt floating valve spring preload, regardless of the valve are in a state of full open or close the door, upstream and downstream side of the valve seat to block, valve body lumen retentate through the discharge valve discharge. The valve door is closed, Figure 7) Fixed ball valve gate valve body lumen of stagnant toughening can discharge, the discharge device ( Figure 8) Has the following features: (1) in advance to check whether the valve seat leakage injury; 7) reduce the amount of pollution released into the medium replacement of fixed ball valve door; (3) under the working pressure, the valve door are in a state of full open or close, can replace the valve rod stuffing box. 2, automatic pressure release: gate valve body cavity for medium temperature increase caused by the abnormal pressure, do not need through the safety valve, and only by automatic pressure relief valve seat function, the guarantee the safety of valve gate for conveying liquid medium is very important. Ball valve door midplane stagnant medium due to temperature increase, and the abnormal pressure, the valve seat from sphere automatic relief ( Figure 9) Or safety valve installed on the valve body ( Figure 10. ) Ensure the safety of the system. 3, completely sealed, fixed ball valve door has a unique way of seal, fluid completely blocked. To prevent fire, fixed ball valve door still reliable operation, and at the same time can block and ball contact ( Comply with the provisions of the APl, 607. 5, sealing emergency greasing ambulance caused by medium foreign body or fire valve seat seal failure accident, greasing valves provides a connection to a quick note grease gun, convenient and quick to sealing grease injection to the valve seat sealing parts, reduce leakage. 6, reliable valve stem seal and low operating torque seal ring, in addition to the standards for the packing gland is also equipped with & other; O” Type sealing ring, double seal to ensure the reliability of the valve stem seal; Adding graphite packing and sealing grease injection makes the valve stem leakage after the fire to a minimum. The valve rod sliding bearing and thrust bearing makes the valve door operation. Fixed ball valve door advantages: 1, sealing emergency greasing rescue: caused by fixed ball valve door medium foreign body or fire valve seat seal failure accident, greasing valves provides a connection to a quick note grease gun, convenient and quick to import pump sealing grease injection to the valve seat sealing parts, reduce leakage. 2, reliable valve rod sealing and low operating torque: in addition to fixed ball valve door set standard seal ring, the packing gland is also equipped with o-rings, double seal to ensure the reliability of the valve stem seal; Adding graphite packing and sealing grease injection makes the valve stem leakage after the fire to a minimum. The valve rod sliding bearing and thrust bearing makes the valve door operation. 3, full size or reducing: fixed ball valve door can choose according to need full size or reducing structure. Full size pipeline ball valve gate flow aperture is consistent with the pipeline diameter, facilitate pipeline cleaning. 4, the valve stem can be lengthened: according to the needs of the installation or operation, can be extended to valve gate valve rod. Extension rod fixed ball valve door, especially suitable for the occasion of city gas and so on need to be buried laying pipelines. Lengthen the valve rod size according to customers need to be addressed. 5, flexible operation, using a small friction coefficient and good self-lubrication of valve seat and valve rod bearing, greatly reducing the gate valve operating torque. So even in the case of the provided no sealing grease, can also be flexible to operate the valve gate for a long time. Use a fixed ball valve door operation. Must be confirmed before operation line and the fixed ball valve door has been washed. 2. The operation of the valve according to the size of the input signal to drive the valve actuator rod rotation: positive (1/4 turns 900). When the valve shut off. Counter-rotating 1/4 turn ( 900). When the valve opens. 3. When executing agency indicating arrow direction parallel to the pipeline, valve door is open; Indicating arrow and vertical pipeline, valve door is closed.