The Basic Knowledge of Fully Welded Ball Valves

The Basic Knowledge of Fully Welded Ball Valves

How much do you know about the fully welded ball valves?

Fully welded ball valves
Due to the fact that the valve seat is composed of carbonized Teflon sealing rings and disc springs, it has strong adaptability to pressure and temperature changes and will not produce any leakage within the marked pressure and temperature range.
1. Product structure and characteristics
Urban gas: gas output pipelines, main lines, and supply pipelines for various branch lines.
Central heating: large heating equipment output pipelines, trunk lines, and branch lines.
Heat ex-changers: opening and closing of pipelines and various circuits.

Steel plant: various fluid pipelines, exhaust emission pipelines, gas and heat supply pipelines, and fuel supply pipelines.

Various industrial equipment: various heat treatment pipelines, various industrial gas and heating pipelines.

2. Characteristics
There is no external leakage or other phenomena for fully welded ball valves. The machining process of the sphere is tracked and detected by advanced computer detectors, so the machining accuracy of the sphere is high. Due to the fact that the valve body material is the same as the pipeline material, there will be no uneven stress or deformation caused by earthquakes or vehicles passing through the ground, and the pipeline is resistant to aging. The sealing ring body is made of RPTFE material with a carbon content of 25%, ensuring complete leak free (0%). Directly buried welded ball valves can be directly buried underground, without the need to build large valve wells. Instead, small shallow wells need to be installed on the ground, greatly saving construction costs and engineering time.

The length of the valve body and the height of the valve stem can be adjusted according to the construction and design requirements of the pipeline. The machining accuracy of the sphere is very precise, with easy operation and no adverse interference. With advanced raw materials, it can withstand pressures above PN25. Compared with products of the same specification in the same industry, the valve body is small and has a beautiful appearance. The service life of the valve should be over 15 years while ensuring its normal operation and use.

3.​ Features​
1. The valve body is welded from steel pipes.
2. The ball pad is made of reinforced polytetrafluoroethylene.
3. The valve stem adopts explosion-proof design.
4. Temperature range: -60-200 ℃
5. Drive method: manual or turbo transmission.
6. Testing standard: API 598

4. Daily operation and maintenance
In order to extend the service life of the valve, the following procedures should be followed for operation and maintenance.

A. Operation
Frequent operation of the valve not only prevents impurities from accumulating on the surface of the valve seat or ball, but also avoids excessive wear on the embedded parts of the valve seat.​

(1) Opening and closing time requirements. Opening and closing the valve too quickly can cause excessive twisting and load on the valve, resulting in damage to the valve stem. Switching too slowly can cause the surface of the valve seat to be eroded and worn by the medium for a long time. Therefore, the operating time should be kept within an appropriate range. Based on experience, the range of valve switching time (seconds) can be controlled, with a lower limit of half the nominal size of the valve (inches) and an upper limit of five times the nominal size of the valve (inches)

(2) When the valve is in operation, the valve ball should be in the fully open or fully closed position. It should not be in the semi-open or semi-closed position to avoid valve damage.

B. Daily maintenance
The valve seat cavity is the area where pipeline valves are most susceptible to contamination. To ensure the free movement of the valve seat, it should be cleaned once a year and the sealing of the valve should be regularly checked through the drain nozzle. The valve of the auxiliary gas main line is often rarely adjusted. It should be opened and closed at least once a year and injected with an appropriate amount of lubricating grease to prevent the ball and valve seat from bonding and grinding between the ball and valve seat.

The excellent technical characteristics of fully welded ball valves enable the entire gas transmission pipeline to be integrated (all welded), enhancing the overall stress resistance and geological disaster resistance of the pipeline (including valves), reducing the possibility of air leakage, improving valve reliability, extending service life, and making installation and maintenance very convenient.