Questions about tank farm layout in the «Code for Fire Protection Design of Petrochemical Industries»?
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There are currently two tank groups: one is a liquefied hydrocarbon tank group (a semi-frozen ethylene tank with a capacity of 60 m3, and a vinyl chloride tank with a capacity of (20+30) m3), and the other is a tank group for flammable liquids of Class A (three tanks, with a total capacity of less than 500 m3). Question 1: Which specification should be followed regarding the distance between the ethylene and vinyl chloride transfer pipes and the liquefied hydrocarbon tanks? Personally, I think Table 5.2.1 can be followed, with the flexible hose being treated as another type of equipment and a distance of 9m being applicable; however, some people in the company suggest following Table 4.2.12, which specifies a distance of 25m between the vehicle loading/unloading station and the liquefied hydrocarbon tanks. 2. Which regulation and which clause govern the distance between the pumps for liquefied hydrocarbons and the hydrocarbon storage tanks? Personally, I think Table 5.3.5 with 15m is feasible, but some in the company believe that Table 4.2.12 with 25m should be used. 3. Can a low-temperature ethylene pump be placed together with a vinyl chloride compressor and an ethylene vaporizer? 4. Does a flexible hose also need to be installed at the vehicle loading/unloading station?
1. Personally, it is based on the spacing between system units; that is, 4.2.12. The petrochemical regulations do not include the concept of a dedicated loading/unloading station for tank groups – one loading/unloading station can serve multiple tank groups. . 2. For the dedicated pumps of the tank bank, the value is 15 meters; for non-dedicated pumps, it is 4.2.12. 3. Yes, it’s possible. Besides, isn’t the ethylene vaporizer on the ethylene vehicle? . . 4. This is unclear; let’s go by the strict rules. . .
1. Personally, it is based on the spacing between system units; that is, 4.2.12. The petrochemical regulations do not include the concept of a dedicated loading/unloading station for tank groups – one loading/unloading station can serve multiple tank groups. . 2. For the dedicated pumps of the tank bank, the value is 15 meters; for non-dedicated pumps, it is 4.2.12. 3. Yes, it’s possible. Besides, isn’t the ethylene vaporizer on the ethylene vehicle? . . 4. This is unclear; let’s go by the strict rules. . . 1. Our loading and unloading station is designed for use with one set of liquefied hydrocarbon tanks, not two sets; therefore, I consider it to be among the other equipment listed in Table 5.2.1. 2. Agree. 3. The ethylene vaporizer serves as a production device, with the vaporized ethylene being supplied for use in the workshop.
4. Even if a vehicle loading/unloading station on the factory site has only one dip pipe, it still has other areas for unloading and loading vehicles. As one of the equipment components of such a station, the dip pipe must also comply with the distance requirements specified in 4.2.12.
I based my decision on the following considerations: 1. According to Article 3 of 4.2.12 in the Petrochemical Regulations (p87), the fire separation distances between process units and facilities within a plant shall be determined in accordance with this table; however, the fire separation distances within individual process units or facilities are not subject to this table. 2. Petrochemical Code 6.1.3: The fire separation distances between storage tanks in storage and transportation facilities and other equipment as well as buildings and structures shall be in accordance with the relevant provisions in Chapter 5 of this code. 3. The fire separation distance between the liquefied hydrocarbon tank farm and the liquefied hydrocarbon loading arm shall comply with Table 5.2.1 (treat the liquefied hydrocarbon loading arm as other equipment); the fire separation distance between the liquefied hydrocarbon loading arm and another Class A tank farm (which does not have a loading arm) shall comply with Table 4.2.12.
The tank farm and loading/unloading facilities should belong to two separate system units, in accordance with Chapter 4 of the petrochemical regulations. It is not possible to do so based on the spacing between cards within the system unit (the spacing between the device tank and the equipment inside the device). . . .
For loading and unloading facilities, refer to 6.4; according to the relevant provisions and instructions, they should be separate units (as they are used frequently and are subject to various influencing factors). Even the distance between such facilities and the tank groups they serve shall be determined in accordance with the requirements regarding distances between facilities outlined in Chapter 4. The tank bank and its dedicated pump bank (excluding pumps from other tank banks) are determined in accordance with the relevant provisions of Chapter 5 based on the internal distance within the same facility.
@geddddd (425073) @hhwjt (5090): The required fire separation distance between low-temperature ethylene unloading systems and liquefied hydrocarbon tanks is 30 meters, while the hose manufacturers require this distance to be no more than 20 meters – which does not meet the process requirements. Additionally, it is understood that in many places, hoses are used directly for unloading; so, should these hoses be connected at the unloading station? In our case, the hose-based unloading system is set up right next to the pump, without taking into account such distance requirements. I wonder how you consider the fire separation distance for hose unloading?
Should the hose comply with the fire separation distance at the unloading station? :lol:lol
If unloading can be done using a hose, I think there is no distance requirement for the hose + pump.