Straight Through Diaphragm Valve

Straight Through Diaphragm Valve

Straight through rubber lined diaphragm valve is suitable for non corrosive or general corrosive media. The inner surface of valve body is unlined or covered with optional rubber. It is suitable for different working temperatures and fluid pipelines. Applicable temperature: ≤ 85 ℃, ≤ 100 ℃, ≤ 120 ℃, ≤ 150 ℃ (according to lining and diaphragm material)

How Does Straight Through Diaphragm Valve Work

straight through diaphragm valve drawing

When the straight through valve is opened, its diaphragm rises to ensure smooth flow in any direction; When the valve is closed, the diaphragm seal is tight, which can ensure the absolute closure when there is gravel or fiber in the pipeline.
Compared with weir diaphragm valve, straight through diaphragm valve requires more elasticity of diaphragm. Therefore, this kind of structure limits the scope of choosing elastic material for diaphragm.

Because the diaphragm of straight through diaphragm valve is high elastic material and large area, it is easy to expand and enter the flow channel under high vacuum condition. The expansion degree of the diaphragm is related to the manufacture. The expansion will cause the area of the valve passage to decrease or the diaphragm to collapse. To avoid the latter, the bonnet must be moved up to balance the pressure on the diaphragm. When using the valve in high vacuum, consult the manufacturer.

Straight through diaphragm valve also has full diameter and reduced channel. For valves with reduced flow path, a smaller bonnet assembly is required. For example, a DN50 (NPS2) reduced flow valve should be fitted with a Dn40 bonnet. The structure of the valve cover is similar to that of the weir diaphragm valve. Typical straight through diaphragm valve size series has reached the nominal size of DN350 (nps14)

Full channel valves are mostly used in beverage industry. It can be cleaned with a ball brush with steam or caustic soda without opening or removing the valve from the line.

Straight Through Diaphragm Valve Work Features

1. The opening and closing parts of elastic seal ensure no internal leakage;
2. The streamline flow channel makes the pressure loss small;
3. There is no stuffing box, so there is no leakage;
4. The valve body and the cover are separated by the middle diaphragm, so that the valve cover, stem and other parts above the diaphragm are not eroded by the medium;
5. The diaphragm can be replaced and the maintenance cost is low;
6. The variety of lining materials can be applied to all kinds of media, and has the characteristics of high strength and good corrosion resistance.


Body MaterialCast Iron, Cast Steel, Stainless Steel