Fabricated Steel Globe Valve

Description

Compared to the needle, gate, and butterfly valves, Fabricated Steel Globe Valves are superior.

The majority of cities in Iran have manual control of their water supply networks via gate valves, which creates two significant issues:

1. Gate valves do not control valves and are only suitable for check operation, and this means that these valves must be fully open or fully closed, as their characteristic curve allows for minimal changes in flow and pressure during the first 90% of the valve stroke but significant changes during the final 10%. The control must be carried out in extremely small passages within the valve, which increases flow rate and generates a water jet that rapidly destroys the valve sealing seats, which are frequently made of incredibly soft brass. After a while, the same waterjet causes damage to the sealing surface of the butterfly valve.
2. Gate valves seal by the contact of two wedge surfaces, such as the disc and the sealing seat at the end of the valve disc drive, which means that the disc is loose inside the valve when it is not entirely closed. Due to the constant vibration caused by the passage of water, this loose state causes the valve disc to break down, destroying the valve’s internal components.

As a result, operation and control of water supply networks via gate valves, which are common in most of the country’s cities and have incredibly high repair and maintenance costs, are required. A portion of this is due to the valves being destroyed, and the remainder is due to the personnel costs associated with this operation (which in practice, cannot create the desired conditions).

Valves with a piston mechanism should be used to control pressure or flow. Globe valves (for flow and pressure control) and needle valves are two types of ductile iron ball valves.

Specifications and applications of gate valves: