Overview

This chapter deals with the selection, location, design, and construction of hot taps in piping systems. The emphasis is on hot taps using welded branch fittings, but there is a discussion on bolted-on fittings. This discussion is not intended to be a full treatise on hot tapping. Such a work would be extensive and would fill several volumes. This chapter is a mere introduction to hot tapping and how it relates to piping and pipelines.

The reader is encouraged to obtain a copy of the API RP 2201 Safe Hot Tapping Practices in the Petroleum & Petrochemical Industries [Reference 1].

Hot tapping is the technique of creating an opening in an operating pipe by drilling or cutting a portion of the pipe with an attached fitting. The attached fitting can be a mechanical (bolt-on) or welded branch fitting to the operating piping.

The purpose of hot taps is to add connections to piping without depressurization or disruption of normal process operations. Hot taps may also be used to make connections into piping in circumstances where it would be impractical to use hot work. Hot tapping is also used to isolate sections of piping for maintenance by plugging or stoppling, as discussed in the previous chapter, or to connect a new piping system to an existing one. Oftentimes during expansion projects, hot tapping into existing lines is necessary to avoid shutting down the existing operating facilities.

Hot taps are used only where it is impractical to take the...