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| SEV Gate Valve Construction Features Function |
| ● Construction |
| SEV gate valve adopt OS&Y. B.B. Rising Stem, Non-rising handwheel, which is in |
| accordance with international general standard. |
| ● Body and Bonnet |
|
After being strictly calculated, the design of the body and bonnet possess good |
| performance of strength, rigidity, perfect seal and flowing ability. It makes more |
| reliable for the seal of the packing and more convenient for the replacement of the |
| packing to have assembled backseat onto the bonnet. |
| ● Wedge |
|
SEV gate valve adopt H type flexible solid wedge, which have excellent fitness to the |
| body deform and so can guarantee reliability of the valves seal. This design can |
| also reduce the overload caused by the difference in temperature load of the stem |
| and the sealing surface. Particularly, it can avoid hard-to-open jam caused by the |
| over load of the wedge. So this design is more fit to steam and other high |
| temperature devices. |
|
● Seat |
| For SEV gate valve in different pressure or specifications, the seat would have the |
| following types: |
| 1.The connection of the seat ring and the body may either be threaded or welded |
| type. The threaded type seat is easy for disassemble, maintenance and replacement. |
| 2.The sealing surface is directly welded on the body. |
| 3.For stainless steel gate valve, the sealing surface is machined and finished on |
| the body. |
|
● Stem and Yoke Sleeve |
| T type is used for the connection between the stem and the wedge disc. The |
| strength of the connection is guaranteed by integral forging of the T head and stem. |
| The thread coordination of the stem and yoke sleeve adopts appropriate fit |
| clearance and special thread remedy to ensure flexibility of the valve’s actuation. |
| While opening the valve, the top assembled yoke sleeve can ensure that the |
| opening position of the disc will not change at all, even though the handwheel is |
| disassembled. For high pressure and large size gate valve, there is a bearing is |
| designed at the yoke sleeve. |
| ● Packing and Lantern Ring |
| The dimension and quantity of the packing conform to the standard to ensure the |
| reliability of sealing. Packing materials are made of graphite (free of asbestos). The |
| lantern ring may be supplied if the customers require. |
| ● Gasket |
| Connection between body and bonnet adopt bolted flange. The gasket of flange |
| shall be as follows: CLASS 150 Flat Gasket CLASS 300 Female or Male Gasket |
| CLASS 600 & larger Octagon Ring Gasket The metal spiral wound gasket with inner |
| ring and filling with graphite makes more reliable for the seal of the gasket and |
| excellent capability of disassembling and reassembling. | |
| |
| According to the different usage, on the basis of the valve body material, SEV globe valve shall include: Carbon Steel |
| Series, Stainless Steel Series, Low Temperature Steel Series, High Temperature Steel Series, Sulfur-proof Series. | |
| Notes: |
| 1. All materials conform to ASTM specifications. |
| 2. Sealing surface material code is SEV code, please refer to figure number. |
| 3. Materials above is general valve design standard. The valve may be obeyed to SEV reconfirmation when the customers |
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