PTQ Q4 2022 Issue

also shown. Pipe shoes/guides are not shown to maintain image clarity. INTS model The INTS model is used when the vessel support is combined with external steel framing supports. In this case, load interaction must be considered in the design of the pile cap. An example of this sup- port system was previously shown in Figure 1 for vessels SV01-SV03. Depending upon the size of the ves- sel, two or more saddle wall sup- ports can be used to reduce the loads on each wall. As illustrated, vessel SV01 is supported by four saddle walls, while SV02 and SV03 are supported by two saddle walls. To provide further insight, Figure 3 illustrates details of the INTS sys- tem from various angles. The x-axis and z-axis directions are also shown to identify the snapshot orienta- tion. Figure 3a shows an example of the INTS model supporting a ves- sel using four concrete walls. This scheme will be referred to hereafter as ‘Case A’. The vessel support of Case A is integrated with the service plat-

Figure 3 Snapshots of various (INTS) systems

Horizontal vessels can be categorised as: a) Steel mounted saddle support (SMSS) system b) Integrated saddle support (INTS) system c) Isolated saddle support (ISS) system.

form framing. The concrete walls are shown as red bricks, and the vessel is coloured silver. Enlarged detail of the front part is zoomed in Figure 3b . An alternative INTS system for two horizontal vessels is shown in Figure 3c . This support scheme is referred to as ‘Case B’. The saddles of each vessel using this model are supported using two concrete walls. Figure 4a illustrates the loading mechanism during oper- ation to support the INTS Case A system. In this scheme, four saddle walls are required to support the vessel. Note that the vessel diameter changes between the intermedi- ate saddle walls. For smaller vessel sizes, two wall sup- port systems can be used, as shown in Figure 4b . The wall size should be carefully determined to accommodate the vessel kinematics. Walls supporting fixed saddles in both schemes are denoted by W1, while walls W2 to W4 sup- port the sliding saddles. Concrete pile caps are used to transfer the loads from saddle walls to the piles. The wall height is denoted by D w and is determined by piping design. Base plates are used to connect the vessel saddles to the concrete walls. Figures 4c and 4d show sections through the saddle base plates. The fixed saddle is anchored to the concrete wall support using four anchor rods. It is reasonable to assume in the analysis model that it simply supported boundary conditions for this support type. Teflon coating is bonded to the sliding base plates to reduce friction forces during operation. A roller support can be assumed to simulate the saddle sliding condition. During operation, the vessel expands in the direction

The SB houses electrical equipment and is sized based on the interior spacing. The CB is a single-story building housing critical instrumentation controls and is occupied continuously. SMSS system The SMSS model is recommended for vessels required to be placed at high elevations. Examples of this system are vessels SV07-SV09 in Figure 1 . The elevated sulphur ves- sels using SMSS are mounted on steel skids attached to the primary steel framing. Figure 2 shows various schemes that can be used for the SMSS system. For illustration, Figure 2a shows the support system of stacked vessels (V A ) and (V B ) located at elevation (z)=14m above grade. A steel framing is provided to support the vessels, as shown in the front view. The two vessels are connected using an intermediate saddle, as shown in Figure 2a . The saddles of the lower vessel (V A ) are connected to the steel skid support connected to the pri- mary framing, as shown in the enlarged front view. Figure 2b shows other examples of vessels supported using the SMSS system. Inlet and outlet pipes and junc- tion boxes are supported on the same platform. Figure 2c shows control valves used to regulate gas flow in pipelines and vessels. Mechanical equipment is shown in dark grey. Steel supports for vertical and horizontal pipe bends are

PTQ Q4 2022