Matters Needing Attention of Forged Steel Gate Valves (Part Two)

Matters Needing Attention of Forged Steel Gate Valves (Part Two)

After the pressure test of forged steel gate valves, the pressure of the gas and water in the sea cavity rises as the temperature rises. In order to grease the valve smoothly, the valve cavity should be empty and the pressure of the valve need to be reduced before the valve is greased. Reducing the pressure of the gate valve in time can ensure the safety of the forged steel gate valve and the greasing process. After the greasing process, the gas and water in the seal cavity are completely replaced by the grease. Meanwhile, the pipe plug, in charge of blocking the leakage of the fluid and air, should be tightened so as to avoid the unexpected accidents.

During the greasing process, we should notice whether the injection opening is blocked or not. Under normal circumstances, the grease firstly flows out from the hole closest to the grease injection opening; then flows from the lowest hole to the higher holes sequentially; finally flows from the highest holes. If the grease does not flow out in this order or the grease cannot flow out, it means that the grease injection opening is obstructed and needs cleaning. 

As for the different qualities of diesel and gasoline, the erosion and decomposition capacity of gasoline should be taken into consideration. During the operation of valves, adding the lubricating grease in time can avoid abrasion. During the greasing process, it is necessary to grease the stem. Meanwhile, if the valve shaft has sliding sleeves or fillers around it, the valve shaft are supposed to be kept lubricated so as to reduce the frictional resistance formed in the operation of valves. If lubrication of the valve stem can not be ensured, the components of the valve will wear due to the increased torque during the electric operation of the gate valve, and opening or closing the gate valve becomes difficult in manual operation. 

Besides, some forged steel gate valves have arrow marks on the surface if the valve body. If there is no FLOW mark, it means the arrow mark stands for the force direction for the seal seat only and can not stand for the flow direction of the media. Usually, the forged steel gate valves have bi-directional flows.
 
matters-needing-attention-of-forged-steel-gate-valves-part-two