Working principle: When the external force acts on the valve stem, the valve stem nut installed on the gate plate and the guide rail groove on the valve body work together to move the gate plate up and down, that is, the valve opens and closes.
When the height of the gate is equal to 1:1 of the valve size, the channel is completely unblocked, that is, the valve is fully open.
Relevant standard (this article takes DN100, PN10 soft seal gate valve for water supply and drainage as an example)
Design criteria: refer to CJ/T 216-2005 "Water Supply and Drainage Soft Sealed Gate Valves" and ANSI/AWWA C509-2006 "Elastically Sealed Non Ring Stem Cast Iron Gate Valves";
Structural length standard: CJ/T 216-2005 "Water supply and drainage soft seal gate valve" short series;
Test Standard: GB/T 13927-2008 "Industrial Valve Pressure Test".
Nominal diameter: DN100;
Nominal pressure: PN10;
Body material: QT500-7;
Stem material: 2Cr13;
Sealing accessory material: nitrile rubber (NBR).
Whole casting body
The valve seat, the connecting flange and the valve body adopt the integral precision casting. The special casting process ensures the precise geometric dimension, so that the sealing surface of the valve body does not need any finishing to ensure the sealing of the valve.
No groove straight channel valve seat
Conventional gate valves often use the bottom of the valve seat with grooves. When the tubes are flushed with water, foreign objects such as stones, blocks, and debris are easily accumulated in the grooves at the bottom of the valve bottom, which can cause close leakage and water leakage. The new soft-sealed gate valve adopts a full-scale flow channel design, which is equivalent to a straight pipeline and has a small flow resistance, ensures fluid flow, is not easy to deposit debris, and does not cause secondary pollution to the medium.
The gate uses ductile iron (QT500-7) frame as a whole to cover high-performance rubber. Mature vulcanization technology and advanced vulcanization technology completely isolate the gate core from the fluid. Integral gate encapsulation not only ensures the sealing size of the gate, but also the rubber and the nodular cast iron stencil are firmly combined, and the rubber will not fall off even if subjected to frequent squeezing stress.
Reliable shaft seal structure
Shaft seals use environmentally friendly "O" seals, which are tightly sealed and substantially reduce frictional resistance. A dust cover is provided at the top to prevent sundries from entering the surrounding environment and damaging the shaft seal. This shaft seal structure can greatly reduce the leakage phenomenon outside, and can guarantee the replacement of "O" seal ring without water, which greatly facilitates the future maintenance and repair of the valve.