Sewer box

Keep Soils Out of Sewers Use road sweeper to remove dirt from roadways and concrete areas which would otherwise blow or be washed into the drainage system. Develop and install new sewer boxes designed to reduce soil movement into sewer system, particularly from Tankfarm area. Estimate cost for installation on a refinery-wide basis. Both items reduce soil infiltration, in turn reducing hazardous solid waste generation. 

Engineering solutions to reduce soil intrusion to the drainage system include (1) using a road sweeper to collect soil and catalyst fines from roadways and process areas before they are blown or washed into the drainage system, and (2) modifying sewer box designs, particularly in earthen areas such as the tank field, to keep soil from entering with water runoff. 

Open-end drain hubs should be located at all tanks, towers, exchangers and associated equipment for fast drainage. Large drains at towers or tanks may be more conveniently handled by an acid-proof concrete or acid-brick-lined sewer box rather than an open-end drain hub. 

CO = CLEAN OUT RL = ROOF LEADER SB = SEWER BOX CB = CATCH BASIN MH = MANHOLE DH = DRAIN HUB FV = FLAP VALVE -0= INVERT... 

Paved areas and unpaved areas outside should have a sewer box or catch basin for each surface... 

The divided areas should be provided with sewer boxes or catch basins. The separate sewer systems are now to be connected to the properly classified sewers. Sewer box or catch basin outlet connections may be at the bottom or side depending upon the sewer invert limits (see Figure 8-3). The term invert refers to the elevation at the bottom inside surface of the sewer pipe. 

Catch basins (see Figure 8-5) should be used as a junction for changes of direction of sewer branch lines. The location of branch sewer junctions may so coincide that a catch basin may be substituted for a sewer box, which would normally be provided for surface drainage. A catch basin should... 

Floor drains inside buildings should only be used to handle water. A sewer box or catch basin should be used where process waste spille e may occur inside a building. 

Sewer Box No. Main Inlet Main Oullet Anxiliaiy M Ul i Top Eievation Bottom Elevation Sewer Bex Diameter... 

For the 90 entry sewer box, the sum of one half the diameter of each of the largest two lines adjacent to each other is added to 12 in. That sum is then multiplied by 4 and divided by v (31416 is used here) ... 

As the Invert elevations of the main at the sewer boxes are confirmed, the actual elevations are recorded on the orthographic piping plan drawing, which is shown in Exhibit 13-7. 

As the details for each sewer box become available (e.g., main inlet and outlet sizes and invert elevations, auxiliary inlet elevation, top and bottom elevations, and the diameter), the information is recorded on a sewer box schedule, as depicted in Exhibit 13-15. This... 

Main lines should be rodded or flushed between sewer boxes. 

Sewer boxes should be made of precast reinforced concrete pipe a minimum of 48 in (1,220 mm) in diameter. The system engineer establishes the need for sealed sewer boxes. Those containing clean storm or fire water do not require sealing, but toxic hydro-. carbon-bearing run-off requires a sealed sewer box that is vented to a safe location, as shown in Exhibit... 

The initial layout of any oily or storm water underground piping system usually takes place after the preliminary plot plan is generated. Even though some equipment locations may be tentative, the plant layout designer can begin to spot the oily water and storm water mains, locate sewer boxes, and establish the invert elevation of these systems at each end of the unit. 

This system picks up drains around boilers and steam drums and is run as a separate system, preferably to the battery limit. It is permissible to tie into a sewer box in the oily water sewer system as long as it is located downstream from any sewer box that collects... 

Sewer boxes Used in oily water sewer systems, sewer boxes ... 

Must have sealed covers in all sewer systems, with the exception of those in storm water sewers located in nonhazardous areas, which may have open graf ing covers—Sewer boxes located in hazardous ar-... 

All lines entering sewer boxes within a process unit must have a 6-in (150-mm) minimum water seal. For off-site sewer boxes, a straight-through flow for sewer mains is permitted, provided that laterals from other areas do not enter the sewer box or mains. The inside top of the outlet line is installed at or lower than the elevation of the inside top of the lowest inlet line before sealing,... 

Sewer main This is the primary drain line in a system it is separated into sections for safety reasons by sewer boxes. 

Sublaterals These collea branch lines and sealed sewer boxes into laterals. 

Exhibit 13-51 highlights a number of features for a lesigner to consider. A prefabricated section of pipe is nbedded into the concrete wall. A Vz in/015-Aick ilate is welded to the secondary line to aa as a water eal. A 1-in drain line is provided to remove any leaked laterial from the containment line. The exterior wall f the sewer box is covered with a polyethylene mem- rane liner that acts as a condary containment barier. 

The data transferred from the drawing to the sewer box schedule to be used by the construction contractor. 

A typical sewer box is displayed in Exhibit 1342. As mentioned previously, all pertinent information for each sewer box must be recorded on the sewer box schedule, shown in Exhibit 13-15, for transmission to the construction contraaor. Exhibit 1343 illustrates a variation to the inlet piping at a. sewer box where provisions are made to rod the line near the sewer box. The systems engineer should be consulted as to whether this feature is required. 

Variations of pipe fittings, catch basins, sewer boxes, trenches, sumps, and lift stations are only a sample of what a plant layout designer encounters in the development of an underground piping system. Available vendor data for fittings, catch basins, and sewer boxes must be used as a reference. Typical cast iron fittings are shown in Exhibit 13-39. The list of labels for these... 

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