What is the venting device of a ball valve? Seeking advice from experts

Can’t see the image? It’s a fixed ball valve. There is an item indicating venting listed for the customer

A control switch for a vent valve that leads from the valve chamber to the outside.

The main concern is abnormal pressure buildup in the valve’s interior, which could prevent the door from opening; therefore, a pressure relief device is added to the middle part of the valve

This post was last edited by jm19890109 on 2018-6-30 at 10:25. It’s easy to understand – there is an additional exhaust valve on the top of the valve body, and an additional drain valve at the bottom.

This post was last edited by wangsir85 on 2018-6-30 at 14:39. 1. This is most likely a data sheet from Sinopec Petroleum Engineering Co., Ltd.; their data sheets look like this. 2. This venting device refers to the discharge mechanism in the cavity of the valve body. 3. Within the valve manufacturer’s terminology, it may be referred to as a vent valve or vent port; in reality, it is not the same as the vent valves used on pipelines, but rather serves to drain air from the interior of the ball valve. 4. As for price, it has almost no impact, unless the technical specifications specify the addition of a ball valve in front of the vent device or something similar. 5. Fixed ball valves generally need to be equipped with venting and drainage devices, as they are manufactured in accordance with pipeline valve standards and possess DBB functionality; therefore, the venting valve and the drain valve serve as accessories for this DBB functionality. As for its function, I won’t go into details; it’s a bit complicated.

As I understand it, the inner chamber of the valve body in a fixed ball valve is equipped with a drain valve and a relief valve; for details, refer to the relevant provisions in API 6D! :hug: