I have a problem that is replacing part of an existing heater line. The section that is being replaced contained cold spring. I do not have any experience with cold spring, and I have a pretty specific question. Please bear with me as I try to set up the scenario.

The line begins at a heater where it ties 4 outlet lines together, runs south 15', east 38', south 50', west 20', and up a tower 20' to the nozzle. Two feet after the bend heading into the 50' run south, there is a support with an axial restraint on the south side of the shoe only. Approximately 8' further south, the line increases in size from 8" to 10" at an 8x10 reducer followed immediately by a flange pair. At the weld point of the downstream flange, there is 2.5" of cold spring specified. There are no other restraints on this line, according to the ISO and field notes, until it gets to the tower nozzle. There is a note on the ISO regarding installation of the axial restraint that states the bumper is to be welded in place before pulling the 2.5" of cold spring. This will effectively give a gap of between 0" and 2.5" on this restraint.

It is proposed to replace the line after the reducer to a point approximately 25' south, eliminating the previously mentioned flanges. Should the cold spring be put back in as specified since this is an existing system? I have my doubts that this was done properly in the first place, and, considering the seemingly unpredictable nature of the method used, am leary of duplicating this system.

Thanks in advance.

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Richard P. Havard
Mechanical Engineer
Mustang Engineering