Attention should be paid when installing:
1) generally, the valve should be positioned before the pipeline installation. The piping should be natural. If the position is not right, it can't be pulled hard to avoid leaving prestress;
2) before positioning the low temperature valve, try to do the open-close test in the cold state (such as in the liquid nitrogen), and it is required to be flexible without the phenomenon of jam;
3) the liquid valve should be configured with the valve stem and the horizontal angle of 10 ° to avoid the liquid flowing out along the valve stem and the increase of cold loss; more importantly, the liquid should be prevented from touching the sealing surface of the stuffing, make it cold and hard and lose its sealing function, thus causing leakage;
4) the joint of the safety valve should have elbows to avoid direct impact on the valve; in addition, the safety valve should be ensured not to frost, so as not to lose efficacy when working;
5) the installation of stop valve should make the medium flow direction consistent with the arrow marked on the valve body, so that when the valve is closed, the pressure is applied to the cone on the top of the valve, and the filler is not loaded. But as for the valves which are not frequently opened and closed and need to be strictly ensured to leak in the closed state (such as heating valve), they can be installed backward consciously to make them close tightly with the help of medium pressure;
6) large-sized sluice valve and pneumatic regulating valve should be installed vertically, in case that the valve core tends to one side due to its relatively heavy weight, which increases the mechanical abrasion between the valve core and the bushing and causes leakage;
7) when tightening the screw, the valve should be in a slightly open state, in order not to break the sealing surface of the valve top;
8) after all the valves are in place, they should be opened and closed again, and the phenomenon of flexibility and no jam is qualified;
9) after the large air separation tower is naked cold, tighten the flange of the connection valve once in cold state to prevent leakage at low temperature due to no leakage at normal temperature;
10) it is strictly prohibited to climb the valve stem as a scaffold during installation.
