Corrugated pipe sealing valve design standards and structural features: Bellows valve bellows valve The valve stem of the bellows seal valve achieves a three-stage seal: Stainless steel bellows protection seal Stem packing seal The bellows gate valve is sealed by the upper sealing structure after the whole process is opened. Design, manufacture and acceptance criteria for bellows valves: Design and manufacture according to GB/T12224, DIN3202, DIN3239, ASME B16.34, API602, MSS-SP-117 Bellows valves undergo a series of rigorous inspection and testing procedures. This includes 100% airtightness and non-leakage testing. For bellows with vacuum requirements, vacuum hermeticity testing can be performed by a helium mass spectrometer leak detector. Structural features of the bellows valve: 1. The valve body and the valve cover are connected by double studs, and the structure is simple and the process performance is good. 2. The valve stem of this valve not only has the stuffing box of the general valve, but also in the lower part of the stuffing box, the movable sealing element-stainless steel bellows is installed in the upper part of the valve cavity, and the medium is enclosed in the valve cavity outside the valve stem. Entering the stuffing box, the valve is more reliable than the general valve in preventing leakage, ensuring the sealing of the valve stem and the valve cover. 3. The stem nut is surface nitrided to improve surface hardness and wear resistance and prevent seizure. 4. The medium flange bolt is made of high-strength alloy steel, which has excellent resistance to high temperature creep and is safe and reliable. 5. The bellows is designed in the inner cavity of the bonnet to avoid direct flushing with the medium and improve the service life of the bellows. 6. The bellows is overlapped by 2~4 times to prevent the valve from leaking due to the single layer damage of the bellows and prolong the service life of the valve. 7. Due to the long design of the bellows, the opening height is large, the main resistance of the fluid is reduced, and the flow resistance coefficient is small. 8. Double seal with packing and bellows to achieve zero leakage. Bellows corrugate pipe
The bellows sealing valve is a valve that uses a bellows as a valve stem sealing member. Bellows valves are often used in applications where valve stem sealing is critical, such as in high vacuum applications and in the nuclear industry. The bellows can be used instead of the stuffing box on the ordinary valve or in combination with the stuffing box to prevent leakage of the stem portion to prevent leakage of radioactive materials or valuable materials, or to maintain a high vacuum. The bellows expand and contract with the lift of the valve stem, and the maximum working pressure depends on the compressive strength and fatigue strength of the bellows.
Inspection and testing according to API598, JB/T9092, DIN3230
Mark by MSS-SP-25.
A pressure measuring elastic element in a pressure measuring instrument. It is a cylindrical thin-walled corrugated casing with a plurality of transverse corrugations. The bellows is elastic and can be displaced under the action of pressure, axial force, lateral force or bending moment. Bellows are widely used in instrumentation and are mainly used as measuring elements of pressure measuring instruments to convert pressure into displacement or force. The bellows tube wall is thinner and has higher sensitivity, and the measurement range is from tens of Pa to tens of MPa. In addition, the bellows can also be used as a sealing spacer to separate the two media or prevent harmful fluids from entering the measuring portion of the device. It can also be used as a compensating element to compensate for the temperature error of the instrument with its variability in volume. It is sometimes used as an elastic joint for two parts. The bellows can be divided into metal bellows and non-metal bellows according to the constituent materials; according to the structure, it can be divided into single layer and multiple layers. Single-layer bellows (see figure) are used more. Multi-layer bellows have high strength, good durability and low stress, which are used in important measurements. The material of the bellows is generally bronze, brass, stainless steel, Monel and Inconel.