Bellows Seal Valve

OPERATIONAL SERVICE FEATURES

In a maintenance aspect, it is true that this type of valve is accounted less than any other type, but the valve have some important advantages as follows:
1.Useful life is ensured.
2.There is a grease nipple on all bellows seal gate valve under current production to ensure correct lubrication over yoke bush.
The threads on stem in every kind of bellows seal valve should be kept clean if possible and lubricated periodically with high temperature grease.
It is recommended the preventive maintenance should be carried out at least every three months.
The maintenance has a particular importance when the valve is employed to high temperature application in case it is essential to use a grease of high temperature type.
At this time, it is desirable that the valve is operated from open to shut, and vice versa.

VALVE SELECTION

As a general guide to valve selection suitable for a specific application, the gate valve should be used mainly for low or medium pressure steam, steam tracing lines, or other services such as heat transfer. The globe valve should be selected for medium or high pressure steam, where the isolation of vessels may be involved in safety problem. It is also used for toxic or explosive media handling and in every case that a trouble may occur in flow regulation.
It should be noted that we have a specially designed valve of which dry escape to gas or fluid is completely prevented. In the valve, conventional stem packing is replaced with flexible metallic membrane where all possible leaking paths through stem or body/bonnet joint are welded.
The bellows units applied to this valve were tested for life cycle to destruction, resulting in satisfactory test results meeting the life time, temperature, and pressure requirements of ASME B16.34.