Gate valve
2014.12.11 / VIEW:1773

Gate Valve Manufacturing Specifications

 Content  Specification
 General design standard  API600
 Pressure-temperature rating  ASME B16.34
 Face to face dimensions  ASME B16.10
 Flange type and dimensions  ASME B16.5
 Butt-welded end  ASME B16.25
 Inspection and test  API598
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.
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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