Fissure

Crevice or crack extending acro strata which are frequently faulted at the same place. Fi ures are the seat into the fitting of a larger a bushing is used, having a male thread on its outside, to fit the larger size, and a female thread in the smaller hole. Reducing fittings have the same function, one hole being large and the other smaller. Elbows are used to turn corners at 90° and at 45°. Tees and Y's are used where a branch is to leave a line which is also to continue. The branch leaves at 90° from the tee, and at 45° from the Y. Where branches leave on both sides the tie becomes a cro . A nipple is a short piece of pipe. To close an outlet a plug with a male thread may be screwed into a fitting, or a cap with a female thread can be screwed on the end of a pipe. When there can be no spring to admit of using a union or right and left coupling, a lock-nut may be used with a coupling on a long right thread.