2021-06-06
Check whether the valves can be used under the required conditions according to the valve model and factory instructions, and conduct hydraulic or pneumatic test if necessary.
❷ It is necessary to check whether the packing is in good condition, whether the gland bolts have enough adjustment allowance, and whether the valve stem and disc are flexible, and whether they are stuck and skewed.
The sealing surface of valve disc must be closed tightly, and the thread quality of threaded valve shall be checked. Unqualified valves shall not be installed and shall be stacked or marked separately.
❸ Remove the impurities in the valve.
Installation
❶ When lifting the large diameter gate valve, the rope should not be tied to the hand wheel or stem to avoid damaging these parts, but should be tied to the flange.
❷ the pipeline connected to the valve must be cleaned.
Compressed air can be used to blow away iron oxide chips, mud sand, welding slag and other debris. These debris, not only easy to scratch the sealing surface of the valve, in which large particles of debris (such as welding slag), but also block the small valve, making it ineffective.
When installing the screw butterfly valve, the sealing packing (thread hemp, aluminum oil or polytetrafluoroethylene raw material belt) should be wrapped on the pipe thread. Do not get it into the valve, so as to avoid accumulation in the valve and affect the medium circulation.
When installing the flange butterfly valve, pay attention to tighten the bolts symmetrically and evenly. Valve flange and pipe flange must be parallel with reasonable clearance to avoid excessive pressure and even cracking of the valve. For brittle materials and low strength valves, special attention should be paid. For valves to be welded with pipes, spot welding shall be carried out first, then the closing parts shall be fully opened, and then the welding shall be completed.