30 BULLETIN 155, TJ. S. DEPARTMENT OF AGRICULTURE. 



bands five-eighths of an inch in diameter, while the failure of a sec- 

 tion of machine-banded pipe due to the wire being cut in this way 

 is not uncommon. 



Small leaks at the joints or seams of wood pipe are usually stopped 

 with wooden wedges. In the case of leaks around the wooden cou- 

 plings of machine-banded pipe, the wedges are driven into the staves 

 of the coupling sleeve, and not between them and the pipe. If a 

 section of machine-banded pipe or a collar fails on account of the 

 cutting of the wire, individual bands with coupling shoes similar to 

 those used for the large continuous stave pipe can be obtained for 

 making repairs. An assortment of these might well be kept on hand 

 where likely to be needed. 



The repairs of a large pipe may call for considerable ingenuity 

 and unique methods. "When several five-eighths-inch bands of the 

 48-inch Mabton (Wash.) siphon were cut by a leak, allowing the 

 ends of two staves to spring out and break off, a diver was em- 

 ployed to make the repairs. At the bottom of the Yakima River, 

 15 to 20 feet under water, steel plates with gaskets, one on the inside 

 and one on the outside of the pipe, were clamped together with bolts 

 so as to stop the leak. 



Under ordinary circumstances the repair of continuous stave pipe 

 is hot difficult. The removal and replacement of staves or portions 

 of them is a matter of frequent occurrence. It is only necessary to 

 remove a few bands, take out the defective stave, spring another into 

 place, and reband. If the pipe has been buried and the threads on 

 the bands have become badly rusted, as they frequently do, any 

 change in the position of the nut may necessitate the use of a new 

 band, though if the body of the band is fit to be used again a new 

 thread may be welded on. This has been done by the Butte 

 Water Co. 



Where a pipe is above ground any landslides coming in contact 

 with it should be cleared away as a precaution against decay, par- 

 ticularly if it is at a point where the pipe is under light pressure. 

 If supported in cradles, mudsills or footings should be renewed 

 as decay progresses, in order to avoid injury to the pipe from set- 

 tling. Weeds permitted to grow along an exposed pipe may, when 

 dry, be a source of danger from fire, and on this account if for no 

 other reason they should be kept down so far as conditions will 

 warrant. 



On many irrigation systems it is necessary to empty the wood 

 pipes in the fall, as a precaution against damage from freezing. 

 Where this is the case they should be kept full as late as possible, 

 and be filled again in the spring just as soon as conditions will per- 

 mit. In some instances irrigation managers close the inlets and out- 

 lets of wood pipes when emptied in the fall, so as to prevent the 



