Drain hub

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. 

Pump blocks should be provided with an open-end drain hub to collect pump casing drains, drainage from gland and seal piping at pumps and drains in pump suction and discharge piping. 

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

Flow diagrams. Drain hubs (see Figure 8-4) collecting drainage from equipment above grade or from paving, which were previously added to the sewer layout, should also be run to the proper classified sewer. Flow diagrams should be consulted to make sure that no drain connection has been omitted, especially those located at the upper levels. Drain hubs need not consist of an... 

A sewer branch or sub-branch should be run in one plane from a drain hub to a catch basin and from a catch basin to a manhole to prevent clogging of the sewer line and for easier rodding and cleaning. Whenever possible, aU branch connections to sewer systems should be made at catch basins or manholes. 

The minimum size of underground sewer pipe, branch or drain hub should be 4 inches. 

The minimum size of the sewer main collecting two or more 4-inch sewer branches or drain hubs should be 6 inches. 

The header-box drain must have a seal loop and clean-oUt plug for inspection just above the drain hub (see Exhibit 7-37). Removal of this plug permits in-iqiection for small leaks in the tube headers in the header box. 

Branch lines in sewer service are installed with the centerline at or below the frost line, with the exception of lines required only for housekeeping drains, which may be installed above the frost line— An example of a housekeeping drain is one in which the outlet from vessel-level instruments is collected and routed to a drain hub at grade. 

This system recovers acid or chemical drains from equipment and piping as well as surfece drainage around such equipment and piping through the use of curbed areas and drain hubs. This system may be routed to a sump for disposal or may be passed through a neutralization facility and discharged into an oily water system. 

Drain hub Usually a 4-in open pipe connection located approximately 4 in (100 mm) above grade or platform in a concrete structure, a drain hub is used to collect drips or effluent from pumps, piping, or equipment drains,... 

Branches Branches collea all the various drain points within a plant (e.g., from catch basins and drain hubs) and tie into sublaterals. 

Tfre starting invert is set with the equiptnou drain located die greatest distance away from die ultimate point of disposal, hub A of Rchibit 13-10. This hub is set with a 12-ln (300-mm) cover from die loV point of paving to the top of the pipe. 

Miscellaneous small bore drains that are used infrequently do not require hubs, as long as there is a hub within 50 ft (15 m) and they can be serviced with a hose. 

Cast iron (or grey iron)—Often used in handling storm and oily water drains. Cast iron is very resistant to corrosion. The hub and spigot design is fabricated in 5 and 10-ft lengths, which may be modified with a special cutting tool. 

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