Setting of the pressure relief valve

The pressure reduction system should be a set of valves; these valves need to ensure a continuous supply of gas during online maintenance, address the issue of overpressure that can occur if the pressure reduction valve leaks, and safety valves should also be installed. For small-diameter pipes, it is advisable to consider using self-acting control valve assemblies. (For reference)

Are there any guidelines I can refer to?

I’m not sure; I’m answering you based on experience. Under what process conditions do you use pressure relief valves?

For the original poster, whether to install a bypass usually depends on process requirements, such as the need for pressurization during initial operation, or the desire to avoid production interruptions during maintenance

Whether to install a bypass valve can be determined based on several considerations: 1. If a bypass valve is needed to assist the pressure regulator in making fine adjustments, then it can be installed； 2. In the case of continuous production during the manufacturing process, or when it is not possible to shut down the operation for an extended period, a bypass valve must be installed to facilitate maintenance. However, for bypass valves used in maintenance purposes, they should not be installed under the following circumstances ； 2.1 When the process fluid has properties such as tendency to crystallize, installing a bypass can lead to clogging of the bypass valve; therefore, it is not advisable to use a bypass in such cases ； 2.2 When the operating conditions do not permit the maintenance of the pressure reducing valve, such as high temperature, high pressure, or the presence of toxic substances, it is necessary to shut down the system in order to carry out maintenance; even with a bypass in place, maintenance cannot be performed. Therefore, it is not advisable to install a bypass under such conditions. In short, the installation of a bypass valve needs to be determined based on one’s own process conditions. In simple terms, if a bypass valve is installed but it doesn’t serve any practical purpose, then there’s no need to have it.

Using a bypass has its positive aspects, especially during pipeline maintenance, as it allows work to continue without interruption. The bypass cost is not high, and it is flexible and convenient to use.

The bypass of a pressure relief valve is different from that of a regular electric valve, as the pressure differences before and after are very large; therefore, I am considering using two pressure relief valves in parallel

It makes no sense – nothing is known about your process conditions, and decisions regarding whether to use a bypass are based solely on personal experience