Regarding the vent port on the tube side of a standard heat exchanger

The pipe connections of the heat exchanger are determined by the process requirements; the manufacturer designs and manufactures it based solely on these process conditions, without increasing or decreasing the number and size of the heat exchanger’s pipe connections.

The vent is mainly used to remove non-condensable gases during hydrotesting or when starting up the system, right? I really don’t know how to arrange the piping for this; I hope those who know can tell me so I can learn as well.

The main function of vent and drain ports is to release gas or liquid during pressure testing; if the process piping can fulfill this role, then separate vent and drain ports are not necessary. Otherwise, they must be installed, regardless of whether the process requires it or not. For example, heat exchangers typically do not have vent or drain ports on the tube side, as the process connections on the tube side are usually located at the top or bottom. Even if the process connections on the tube side are horizontal, vent or drain ports are still required. Furthermore, for single-pass heat exchangers, vent or drain ports must be provided even if the tubes are located at the top or bottom.

Floating-head heat exchangers generally have exhaust and drain ports in the tube box. Although gas release and liquid drainage can be accomplished through the process ports, heat exchangers are generally equipped with separate exhaust and drainage ports, which makes them more convenient to use.

There aren’t any special constraints here; it can be set according to the actual operating conditions

The answers on the 2nd floor didn’t even read carefully the question I asked. Those who suggest ratings should also take a look at the question; ratings are meant to encourage discussion, not to encourage posting. The answer on the 4th floor is not entirely correct; from a process requirements perspective, traps and vents are also often installed in piping systems. The answer on the 5th floor was quite relevant to my question (normally, venting and condensate drainage are provided on the tube bank in heat exchangers, but different manufacturers may or may not include such features on the same type of heat exchanger), but it did not provide an answer to the actual problem. What I mainly want to know is that, even if the process connections allow the manufacturer to carry out pressure testing, it is generally desirable to provide drain and vent ports on both the shell side and the tube side of the pipeline. Since no requirements are specified for venting and draining on the shell side, manufacturers will still include such features, so there’s no need to worry about that. However, the situation is different on the tube side – process connections are often used in place of dedicated vent and drain ports, and when venting and draining are necessary, these must be provided along the pipeline itself. However, after specifying the same standard heat exchanger requirements to manufacturers based on the process specifications, it is common for heat exchangers produced by different manufacturers to have tube-side drain and vent ports, or not have them. In that case, it’s difficult to determine whether to install vents and drain valves on the pipeline. The above problems arise mainly from the fact that in current design practices, detailed construction drawings are often started to be prepared at the preliminary design stage, leaving no time to finalize the process piping work until equipment is ordered. Once on site, during installation, it is common to encounter issues where the actual construction conditions differ from those shown in the installation drawings, raising questions about how to deal with such situations. So I would like to ask everyone how they handle this. As for the issue of whether a pipe train needs to be equipped with venting and condensate drainage, etc., there’s no need to discuss it.

Based on the actual manufacturing practices in our factory, for heat exchangers for which no special requirements are specified in terms of the manufacturing process, we still design vents and drain ports. Moreover, many larger manufacturers specify the need for such vents and drain ports in the technical specifications when ordering heat exchangers.

Both the shell side and tube side of our heat exchangers have vent ports and drain ports; however, we never use them during heat exchanger maintenance. For the discharge medium, use drain valves on the various inlet and outlet pipelines; apply pressure at the valves as well as under the blind flanges at the interfaces of the heat exchanger.

Both the tube side and shell side should be equipped with vent ports and drain ports. On-site construction must follow the drawings; if there are any deviations from these drawings, it is necessary to determine whose responsibility it is, what the reasons for such deviations are, and what consequences they will have. The responsibilities must be clearly defined, and the supervision engineer has the authority to decide whether to accept or reject such deviations.