Questions about instrument air distributor and instrument air storage tank?

This post was last edited by Shutong on 2022-4-18 at 14:56. Please have the original poster take a close look at the HGT 20510-2014 Design Specifications for Instrument Air Supply, as well as the SH∕T 3020-2013 Design Specifications for Instrument Air Supply in the petrochemical industry

Hello, expert. I have reviewed the HGT 20510 specifications. Regarding section 5.2.1, which states that \"In cases where there are multiple instruments or when the instruments are arranged closely together, a branch piping system can be used for air supply, with the branches leading to air distributors or supply points\", is there any specific definition or criteria regarding \"multiple instruments\" or \"dense instrument arrangements\"? Thank you for the reply.

Air source distributor is not mandatory; in areas with high usage, it helps save costs by using an air source distributor. For air storage tanks, it depends on the requirements of the valves; some valves are relatively large and require quick opening and closing. Provide the valve data sheet and detailed requirements to the valve manufacturer, who will then develop a plan to determine whether an air storage tank is necessary. Small factories generally don’t take these into account.

What was said on the 7th floor is correct; using gas meters and valves in a centralized location along with gas distribution units can reduce labor costs. Of course, the material costs will increase. Advantages of gas source distributors: easy to design and aesthetically pleasing ； Disadvantage: High cost (additional clamps and instrumentation tubes required). In relatively small spaces, a large number of air nozzles are used, and using a single air source may not be sufficient due to space constraints. Whether to use it or not – there are no specific mandatory requirements; it depends on individual design preferences, budget, and the owner’s requirements. Whether a gas storage tank is needed for the valve depends on the functions required by the process. For example, in the case of a two-position five-way solenoid valve with dual control, it is not possible to achieve FC or FO states solely in the event of a loss of air or power; instead, a gas storage tank must be used to enable FO and FC states, thereby allowing the valve to perform its functions.

Well-founded and very detailed; thanks to the expert for the guidance

“There is no clear definition for “multiple instruments or crowded areas”. Generally, it can be selected based on the principle of ease of piping. It should be noted, however, that since the outlets of the gas distribution units are usually small-diameter pipes, the amount of gas supplied per pipe and the distance over which it can be delivered are limited; generally, it is advisable for each pipe coming out of the distribution unit to be connected to only one meter. The configuration of the gas storage tank is primarily aimed at addressing potential peak gas usage. Typically, the air supply capacity for instrument air is calculated based on the average air consumption of multiple instruments. However, if there is an instrument with extremely high air consumption, or if multiple instruments may operate simultaneously, or if there is a need to ensure a continuous supply of air despite interruptions, it becomes necessary to consider installing on-site air storage tanks. .

“\"Multiple instruments or crowded areas\" refers to situations where the instruments are located in a relatively concentrated area, close to the source of compressed air supply. If instruments requiring a large gas supply volume are involved, it is better to lay separate gas supply pipes.