From the September/October 2011 issue of NFPA Journal®
By Russell P. Fleming, P.E.
Among the curiosities of NFPA 13, Installation of Sprinkler Systems, are the two small Sections 220.127.116.11 and 18.104.22.168 in the 2010 edition, two small sections that address "revamping" pipe schedule and hydraulically designed sprinkler systems. When NFPA 13 is translated into other languages, a term such as "remodeling" or "renovating" is presumably substituted. The term "revamping" has its origins in shoe repair, when a shoe was provided with a new vamp, the forepart of a shoe or boot that covers the foot behind the toecap.
The sections in NFPA 13 dealing with revamping have been in place for decades and originated as part of a rule addressing return bends: "In revamping existing systems, where it is not necessary to retain sprinklers in the concealed space, ½-inch or ¾-inch close nipples inserted in the existing sprinkler fittings may be used with 1-inch pipe and fittings for the other portions of the return bend."