Bellows globe valves are called differently in different occasions or in different places. Bellows globe valves are also called bellows sealed globe valves. Compared with ordinary globe valves, the bellows globe valves have no leakage and are used in high-risk applications. The medium is relatively safe. The bellows cut-off valve uses a closed bellows that can be stretched and compressed to replace the packing seal, which can effectively prevent external leakage caused by packing loss. It is generally used for the transmission of highly permeable media, such as valves on hydrogen systems, as long as the bellows is not damaged, there is generally no leakage; while the general shut-off valve is sealed with packing, which is prone to leakage.



This is better than ordinary ones. Ordinary shut-off valves are sealed with packing, and the valve stem and packing will slide, which is easy to leak at low temperatures. The bellows globe valve adopts a bellows structure inside. The lower end of the stainless steel bellows is welded to the valve stem to prevent the process fluid from eroding the valve stem, and the other end is placed between the valve body and the valve cover to form a static seal. The double seal design will avoid leakage if the bellows fails, and the stem packing will also avoid leakage. The bellows is welded to the valve stem to maintain stable operating performance and avoid valve stem vibration caused by valve plug vibration. The bellows globe valve is a relatively small category, and the category of steam globe valves is relatively large. Ordinary globe valves can also be used in steam systems; it can be said that the bellows globe valve belongs to the steam globe valve, but it cannot be said that the steam globe valve is Belongs to bellows globe valve.

If the bellows globe valve is leaking, it is better to deal with it. Don’t worry about it. Check and repair it step by step. If the middle flange is leaking, replace the bolts of the middle flange. Just tighten it. If it still leaks, open it to see if the middle flange gasket is damaged. If it leaks at the packing, tighten the packing gland. If the packing is too loose, add packing again, if it is directly on the body. If the pressure is low, you can solder it. If the pressure is high, don't do it, it will be dangerous. There are still many situations for internal leakage. You can do a simple check by yourself.