54 



VETERINARY HYGIENE 



pipe in the direction of the main flow. Junctions at right angles 

 are therefore to be avoided as a body of sewage so entering strikes 

 the opposite side of the main pipe, its own flow is checked and also 



FIG. 14. A Junction. 



FIG. 15. An Inspection Junction 

 with bridled cover. 



that of the main current, part of the inflow is turned aside up the 

 main pipe and the general stoppage of flow leads to sedimentation 

 through the swirling action with resultant blockage. 



Where there are several subsidiary pipes in a system it is advis- 

 able that these be laid to converge at a common point so that there 

 may be convenient access to a number of junctions at one inspection 

 chamber. With modern cast-iron fittings special inspection 



FIG. 16. Inspection Chamber with bolted cover. 



chambers are made with a variety of junction pipes. The smooth 

 inflow of sewage is ensured. Access is easily accomplished by 

 removing the lid which is securely bolted down with gunmetal 

 bolts or by me^ans of a bridle. A layer of prepared felt interposes 

 between the cover and the rim of the chamber so that the latter 

 is rendered both gas and water proof. If necessary, at the point 

 of convergence of tributary pipes these can be disconnected from the 

 distal drain or sewer by joining the chamber to a disconnecting 

 syphon trap, and for convenience in clearing away any obstruction 



