This article is about technical requirement as per international codes and standards for Layout and spacing of pumps in power plants.
Layout and Spacing of Pumps
Pumps Spacing In Plants
Pumps should be located in accordance with Tables 1-A and 2-A, Figure 1 and as outlined below. The normal operating temperatures of the fluids handled by pumps shall be used to determine if the fluid is considered combustible, flammable, or above auto-ignition. Any combustible fluid heated above its flash point shall be considered a flammable liquid.
When locating pumps special consideration should be given to high-pressure and high-temperature pumps. The pumps may be grouped with other pumps that present similar hazards, but should be separated from pumps that present different hazards, to minimize damage due to spill fires. Pumps handling hydrocarbons above auto-ignition or 260 °C may be grouped together but should be located at least 4.5 m from other pumps handling hydrocarbons. Pumps handling flammable liquids at pressures above 3.45 Mpa gage may be grouped together but should be located at least 4.5 m from other pumps handling hydrocarbons.
Provide sufficient clear area around the pumps to allow removal and installation of casing sections, motors, and internal elements. Maintenance clearances around the pumps can be established from the vendor drawings. Pumps grouped in rows, as along a pipe rack, should have as a minimum:
A clear maintenance aisle, 3.7 m wide and 3.7 m high, under the pipe rack to facilitate the maneuvering of a cherry picker or other type of maintenance equipment.
An adequate aisle, 1.5 m minimum clear width, at the pump ends for removal of internal elements or casings.
An aisle, 1.5 m minimum clear width, between pumps.
Adequate access around hot oil pumps. Consider the large amount of small trim piping required. Trolley beams or other means must be provided for removal and installation of large vertical pumps, if the pumps are not accessible to a crane. Clear space must be provided above these pumps for removal. Care must be taken to locate the trolley beams directly over the center of the pumps.
When a pump and its spare are exposed to a common fire hazard, additional separation between them may be justified. For example, the pumps might have long replacement lead times that could cause excessive business interruption if both were lost in a fire, or the pumps could be exceedingly expensive.
Locate transfer pumps offsite in areas outside of tank dikes. Space the transfer pumps at least 3 m from other non-associated pumps, at least 15 m from unit substations, a minimum of 60 m from main substations, and 9 m from main pipeways. The increased separation from the main pipeway is due to the relatively large size of transfer pumps.
Spacing between pumps handling flammable or combustible liquids and pipeways that have NOT been fireproofed should be at least 9 m, otherwise see Figure 1.
Fire Pumps Spacing in Plants
Firewater pumps are to be located 60 meter from shell of atmospheric storage tanks containing hydrocarbons, or 30 m from top centerline of dike, whichever is greater. Spacing requirements can be reduced to 30 m for process equipment and to centerline of the dike of atmospheric storage tanks when multiple fire pump locations are used and each of the pumps supplies 50 percent or less of the maximum single event required capacity.
Table I – Spacing of Pumps to Fireproofed Elevated Process Area Pipeways and Structurally Supported Air Coolers
| PUMP TYPE | PUMP FIRE PROTECTION | RECOMMENDED SPACING TO PIPEWAYS AND AIR COOLERS |
| Pumps handling combustible liquids at temperatures below their flash points | With or without water spray systems | Adjacent to but not under |
| Pumps handling flammable liquids(or combustible liquids at temperatures above their flash points) | Without water spray | 3 meter |
| Equipped with water spray systems | Adjacent to but not under | |
| Pumps handling flammable or combustible liquids at temperatures above their auto-ignition temperatures | Without water spray systems Equipped with water spray systems | 4.5 meter 3 meter |
| Pumps handling flammable liquids(or combustible liquids at temperatures above their flash points) at discharge pressures over 3.45 Mpa | Without water spray systems Equipped with water spray systems | 4.5 meter 3 meter |
Read Main Article: Safety Considerations for Plant Layout Levels