The skills of dual-valve design
Thread Content
Typically, chemical processing equipment is equipped with dual-valve control. For example, the dehydration pack of a container is usually controlled by two gate valves, one at the front and one at the back; there are also cases where it is controlled by a front gate valve and a rear ball valve. I noticed a detail: there is always a short section connecting the two valves. Excuse me, experts – is this a requirement per the standards? Is it okay to connect the gate valve and the ball valve directly together?
This is indeed a common scenario; when there is a short circuit in the middle, it’s necessary to include a venting or drainage mechanism. I still haven’t figured it out; hoping an expert can help? !
This issue was discussed on the forum some time ago; I can’t remember the details exactly. The original poster can search for it if they have time.
1. Adding a short circuit in between facilitates the connection of the two valves; if the valves are connected directly, it is difficult to install the bolts and nuts due to the size of the valve bodies themselves； Using a short circuit between two valves or fittings is a common practice. 2. The straight pipe section between the two valves constitutes a confined space; a liquid discharge valve should be used to remove the liquid from this area
As long as care is taken to select flanges of the same standard when choosing valves, they can be connected directly without the need for adapter pipes
This is mainly done to facilitate the installation and maintenance of the valve{:2_36:}
A short pipe is added in the middle along with a small valve; this valve is an inspection valve~
It also depends on whether the bolt can pass through the connection of the double-valve flanges; sometimes it is blocked by the body of the valve and cannot be inserted into the flanges.
In addition to the need to install the coupling bolts, it is also necessary to release the pressure inside before removing the valve.
The design of dual valves is intended to achieve a complete isolation of equipment or pipelines; generally, an exhaust valve is installed between the two valves. When the dual valves are closed, if any leakage occurs, it is discharged directly through the exhaust valve, ensuring complete isolation