Width of the pipe gallery
Thread Content
1 The width of the pipe gallery is determined by the following factors: a) the number of pipes per floor of the gallery； b) Are pumps and heat exchangers installed below the pipe tray, and are air coolers installed above it? ； c) The width required for the instrument trays and cable trays installed on the pipe tray. 2 Estimate the width of the pipe gallery based on the number of pipes. The pipeline density varies across different sections along the length of the pipe gallery; generally, the equipment is dense in the central area of the facility, resulting in the highest pipeline density there, while there are fewer pipelines at the beginning and end sections near the boundaries of the facility. At the same time, some pipelines are suitable for being installed on the upper layer while others are suitable for the lower layer; therefore, the routes of the process and utility pipelines in the upper and lower layers of the pipe gallery should be planned based on the plant layout plan as well as the process piping and instrumentation diagrams, so as to serve as a basis for estimating the width required for different sections of the pipe gallery. The width of the pipe gallery can be estimated using the following formula. W = f × n × s + A. Where: W is the width of the pipe gallery, in meters ； f – safety factor; when the estimation accuracy is low, f is set to 1.5, and when the accuracy is high, f is set to 1.2 ； n-Number of pipes in a certain layer of the pipe tray with a DN of not more than 450 ； s-average pipe spacing, m ； A – Additional width, in meters. ①Due to the significant differences in plant scale, the diameters of the pipes on the pipe tray vary greatly; hence, the concept of \"average pipe diameter\" is introduced. The average pipe diameter ranges from DN100 to DN250; the value of the average pipe diameter should be selected based on the specific conditions of the installation, and the average pipe spacing s is then determined using this average pipe diameter. ②Since pipes with a DN of 450 or more occupy a large width, they should be calculated separately; it is advisable to reserve a 10%–20% margin in the pipe tray within the installation. The combined width of these two elements constitutes the additional width A. The reserved space in the conduit should run throughout the entire conduit. 3 When instruments and cable trays are installed in the ductwork, the width required for them should be added to the width of the ductwork at the level where those trays are located, based on the data provided by the relevant specialties. 4 When air coolers are installed above the pipe gallery, the width of the gallery shall meet the requirements of the air cooler framework dimensions. Generally, the width of the pipe gallery @ should be consistent with the length of the frame. For example, in China, the length of the frame for 9m tube bank air cooling is 8.7m, so the width of the pipe gallery is also set at 8.7m, allowing the positions of the frame columns to coincide with those of the pipe gallery columns, which facilitates structural design. 5 When pumps are installed beneath the ductwork (in a single row or double row), the width of the ductwork should take into account the length of the pumps as well as the width of the access passages for operation and maintenance. There should be a passage of at least 1.25 m at the pump end, and a passage of at least 2 m between the motor ends of dual-row pumps. When the pump’s inlet and outlet pipes need to pass upward through the lower pipe tray, a gap should be reserved in the lower pipe tray for the pipes to pass through. If the cable used to power the pump is laid underground, the required width of the cable trench must also be considered. In addition, the required width of the main pipes for the cooling water and drainage pipes of the pump must also be considered ； 6 Since the pipeline layout density varies throughout the entire pipe gallery, there are usually fewer pipelines at the beginning and end sections of the gallery. Therefore, if necessary, the width of the pipe galleries at the beginning and end can be reduced, or a double-layer pipe gallery can be converted into a single-layer one. 7 The width of a single-span pipe gallery generally does not exceed 10m. When it exceeds 10m, an additional span can be added or it can be a double-span (equidistant or non-equidistant).
The width of the pipe gallery is determined based on multiple factors. First, the width of each layer of pipe gallery depends on the number of pipes. Secondly, whether pumps and heat exchangers are installed beneath the pipe rack, and whether air coolers are installed above it, all affect the width of the pipe rack. In addition, when installing instrument tray and cable trays on the pipe rack, the width required for them also needs to be taken into account. We can estimate the width of the pipe gallery based on the number of pipes. The pipeline density varies across different sections; it is highest in the ducts in the central area where there is a high concentration of equipment, while the number of pipelines is lower in the sections near the boundaries. Some pipes are suitable for being placed on the upper layer, while others are suitable for being placed on the lower layer. Therefore, the routing of pipes on the upper and lower layers of the pipe tray is planned based on the layout plan of the equipment and the process piping and instrumentation diagrams, and the required width for different sections is estimated accordingly. The width of the pipe gallery is estimated using the formula W = f × n × s + A, where W is the width of the pipe gallery, f is the safety factor (1.5 when the estimation accuracy is low, and 1.2 when the accuracy is high), n is the number of pipes on a certain floor whose DN is not greater than 450, s is the average pipe spacing, and A is the additional width. The average pipe diameter can be selected based on the conditions of the installation, and it is used to determine the average pipe spacing s. Pipes with a DN of 450 or less occupy more width, requiring separate calculation along with a 10%–20% margin. The final width of the ductwork equals the sum of the pipe widths plus the additional width. If the ductwork is equipped with instruments and cable trays, the width required for these should be added to the width of the ductwork. Similarly, if air coolers are installed above the duct bank, the width of the duct bank should meet the requirements of the air cooler frame dimensions. When installing pumps beneath the pipe gallery, consideration must be given to the length of the pumps as well as the width of the access passages for operation and maintenance. There should be a passage of at least 1.25 m at the pump end, and a passage of at least 2 m between the motor ends of dual-row pumps. If the pump’s inlet and outlet pipes need to pass through the lower pipe tray, a gap should be reserved in the lower pipe tray for the pipes to pass through. If the pump’s drive motor is connected via cables laid underground, the width required for the cable trench must also be taken into account. In addition, the width required for the main pipes of the cooling water and drainage pipes for the pump also needs to be considered. Since the pipe layout density varies throughout the entire duct, there are fewer pipes in the sections at the beginning and end of the duct. Therefore, if necessary, the width of the pipe galleries at the beginning and end can be reduced, or the double-layer pipe gallery can be changed to a single-layer one. Finally, the width of a single-span pipe gallery generally does not exceed 10m. When it exceeds 10m, considering adding an additional span or designing it as a double-span (equidistant or non-equidistant) is an option. .
Understanding the use and management of utility tunnels is indeed necessary; I’ve learned from it, thanks for sharing