The main artery tube shelf is a processing unit. Connects all equipment with lines that cannot pass through adjacent areas. Since it is located in the middle of most factories, the pipe rack must be installed first, before a row of equipment is blocked. Process pipe racks, plumbing tools as well as tools and trays for power cables as well as equipment installed on all of them. Figure 1 shows a typical pipe rack.
This is a small presentation about pipe rack and piping rack. It will be very useful for beginners in the plumbing industry. This article will briefly address the following points:
- Introduction
- Pipe racks
- Pipe rack design criteria
- shapes
- Future space
- Tube shelf width
- goods release from Customs
- Load the tube rack
- Rack plumbing
- Line position (process and tools)
- Hot lines and cold lines
- Larger size lines
- The distance between the pipes
- Anchor Bay
- Unit battery limit
- Expansion rings
- Pipe path
- Trays
Data required for pipe shelf development
Preliminary data required for detailed pipe shelf development:
- Plot design
- P&ID
- Customer specifications
- Building materials
- Fire-fighting requirements
- Legal requirements
Figure 1: Ordinary pipe rack
Pipe rack design criteria
Tube shelf shapes
There are different shapes of tube rack such as L / T / U / H / Z. These shapes should be considered based on the available area.
Future space requirements on pipe shelves
The total width of the tube shelf should include 25% of the extra space for future expansion / modification in the unit for shelf widths up to 16 meters and 10% for shelf widths above 16 meters. The age percentage of future space is usually based on customer needs.
Tube shelf width
Shelf width should be 6 meters, 8 meters, or 10 meters for a single bay and 12 meters, 16 meters or 20 meters for two shelves with a maximum of 4 floors. The distance between the pipe shelf portals should generally be 6 meters. However, depending on the size of the pump under the pipe rack, it can be increased up to 8 meters.
Clearance criteria in the tube shelf
For units, the distance under the pipe shelf must be at least 4 meters in both longitudinal and transverse directions.
For off-site, the distance under the pipe shelf should be at least 2.2 meters in both longitudinal and transverse directions.
Road clearance should be 7 meters for the main road and 5 meters for the side road.
Rack width selection criteria
See Figure 2 for more details.
Figure 2: Shelf width selection criteria
Load the tube rack
Pipe shelf loads should be given by the stress group to the civil engineering structure to design the pipe shelf.
- Stable load (dead load): Insulation weight of pipe, valve and load
- Thermal load: The load by the thermal expansion of the piping and the reaction force by the internal pressure of the expansion tail
- Dynamic load
- Load by plumbing vibration and wind and earthquake
- Stable load (live load): Liquid load for hydrostatic pressure testing
Instructions for plumbing racks
Position of lines on the shelf:
Process lines are often maintained at a lower layer and applied and hot process lines are maintained at a higher level.
Hot lines and cold lines on the shelf:
In general, hot and cold lines should exist on different floors or in different groups on the same floor.
Pipe distance inside the pipe shelf:
The minimum distance between adjacent lines must be determined on the basis of OD. Larger flange size (minimum score of # 300 must be considered), OD of smaller pipe, separate insulation thickness and additional 25 mm distance. Even if the flange does not appear at least. The spacing should only be based on the above. The distance of the real lines, especially in the places of bending and the “L” ring, must take care of the thermal expansion / thermal shrinkage / non-expansion of the adjacent line. Non-expansion / thermal contraction may stop the free expansion of the adjacent line at the “L” bend.
Larger size lines:
Large lines (14 inches and larger) should be placed close to the column to reduce the bending moment of the beam. Water lines longer than 30 inches should not be routed from the pipe rack, these lines should be routed underground.
Anchor bay on the pipe shelf
If the concept of anchor bay is accepted, the anchors on the shelves should be provided on the bay anchor. Otherwise, the anchor must be distributed in two to three consecutive positions.
Anchors must be provided inside the unit on all outgoing telephone lines of the unit.
Pipe path:
Shelves should be designed so that the pipes have the shortest possible path and provide clear rooms on the main corridors, side corridors and platforms.
Trays:
In general, the top layer should be maintained for power cable trays (if not in the underground trench) and tool ducts / cable trays. Cable tray to take care of the necessary distances for the structure fire.
Battery Limit ( ISBL ):
Process line crossing units (inside units or from the unit to the main pipe path) are usually provided with block valves, blind glasses and drain valves. Block valves should be grouped and the location of the block valves in the vertical direction of the pipe is preferred. If block valves are to be located in a pipe path above the head, stepped access to the platform above the lines must be provided.
Expansion rings on the tube rack
See Figure 3.
Figure 3: Examples of expansion rings
- Expansion ring is provided in high temperature lines. This information should be provided by the stress group. All rings should be placed around only one column.
- Group the lines and install a large plumbing and high temperature plumbing to the edge of the pipe rack.
- If necessary to install an expansion ring on the condensate line, do this horizontally to prevent water from pounding. But if the horizontal loop is impossible, do as above.