Gate valve: wedge and knife
1-on the variation of the valves is a gate valve used mainly for installation on the roads transporting the bulk material, weighted technical mixture (sewage, sludge), gas and air flow. Standard valves to cope with this type of threads are not able to, because particles of matter enter between the shut-off device and a saddle valve, not allowing to fully cover the section.the
What is gate valve?
Gate valve, in contrast to other varieties of valves that can completely overlap the section of the pipeline with sufficient tightness, and the structure of the material does not play any role for her.
Locking element in the gate latch acts as a wedge or a flat knife that, moving perpendicular to the flow, covers the cross section of the device, cutting the thread. Directly in the form of a locking slide element is wedge and knife gate valves.
Device slip type
Wedge gate valve set then if you need a very securely shut off the flow, it can work under strong pressure working environment. A closing element of a valve of this type has klinovo shape similar to the shape of the surface are also saddle the device with seals. The main use of this valves are of the sewage system.
Under the influence of the force generated during the rotation of the spindle, move the locking wedge in a direction perpendicular to the movement of the working environment. When fully closed cross-section, the wedge, under the acting force, is deformed (within the limits of elasticity of the material), to achieve maximum sealing.
Device gate valves of this type have a number of drawbacks that must be mentioned:
- With intensive use, the seals quite often fail;
- the Working surfaces of the wedge and seat the device must be perfectly aligned to each other, this must be pre-lapping, which is quite time consuming;
- When a surface of the wedge (corrosion, cracks, deep scratches) broken sealing valve, in addition, such damage can lead to jamming of the mechanism;
- high temperature shut-off wedge has the ability to expand, which also leads to a crash and the inability to regulate the flow.
for this reason most often applies another modification, knife gate valve, which is characterized by practicality and reliability. By the way, Ukraine is to buy quality, you can:
Knife gate valve area of application
a closing element of this valve has a relatively small thickness and acts like a normal knife.
Therefore, the field of use of such valves is practically unlimited, it is:
- oil-Refining industry;
- Pulp and paper mills;
- the Mining industry;
- the ventilation System and the sewers.
we should also mention that the knife gate valve can be applied even in pipelines operating at vacuum (vacuum technology).
Translated by "Yandex.Translate": translate.yandex.ru.