The cast steel globe valve is essentially a high-end faucet switch, specifically designed to completely cut off liquids or gases in pipelines. This thing looks like a lump of iron, but it is much more durable to use than ordinary valves!
1. He looks big and rough, but has hidden mysteries inside
Valve body: Made entirely of cast steel, one-third lighter than cast iron valves, easy to lift.
Valve disc: The core seal is coated with metal alloy, and even high-pressure steam cannot escape after being tightly closed.
Valve stem: surface nitriding treatment, can be twisted thousands of times without wear, and can also be easily twisted with residual hands.
2. The operating principle is similar to twisting bottle caps
Turning the handwheel clockwise is like tightening the lid of a thermos cup, with the valve disc firmly pressing against the sealing surface of the valve seat, and the medium (water/oil/gas) directly trapped in the pipeline. But pay attention to the flow direction of the medium:
Low risk scenario: Liquid enters from under the valve disc, and closing the valve requires more force (which can easily bend the valve stem).
High pressure scenario: The liquid rushes down from the top of the valve disc and is compressed and sealed by the medium pressure, making it easy to twist without leakage.
3. Clearly indicate the applicable situation
Acidic and alkaline liquid pipelines in chemical plants;
High temperature steam pipeline of power station (capable of withstanding 300 ℃);
Oil pipeline (with anti-corrosion coating).
4. The advantages and disadvantages are directly reflected in the face
Advantages: Easy maintenance (no need to disassemble the entire valve to replace the sealing ring), and a lifespan three times longer than plastic valves.
Disadvantages: High fluid resistance (equivalent to putting a mask on the pipeline), and occupying space when fully open.
5. Guide to Avoiding Pits
Do not throw the protective cover when unpacking the new valve, as the welding slag in the pipeline will be directly scrapped.
Warehouse storage must be elevated off the ground, and cast iron parts that are damp and have rust spots will inevitably leak.
The installation direction cannot be reversed, and the arrow mark on the valve body should face the direction of medium flow.