How can one check whether pipe supports need to be replaced in an aging plant ?

For Piping, we have B31 G for determining remaining strength of corroded piping.

What about standard supports viz. line stops & guides, engineered supports viz. rod and spring hangers and secondary structures.

How life extension of an aging plant can be made just on the internal corrosion of the piping only, where there is visible external corrosion of a plant piping's primary supports ?
reg,
sam

API-570 Appendix-D & ASME B31.1:Appendix V are referring to this issue.
https://www.google.co.in/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=inservice%20piping

Maintenance of piping system integrity is an important issue, indeed!

Just, for an example - we in India once cheered the availability of no city administration to obstruct at the inception of smart city of Gurgaon by private developer.

Last couple of days in waterlogged Gurugram (new Smart name of Gurgaon), we are realizing what a lack of maintenance program in an fast expanding smart city can do!

When we are spending on modification of existing refinery or petrochemical assets, we need to keep a vigilant eye on proactive maintenance on piping supports which do not have enough standby or margin - even one support failure can cause severe accident!

When we put last painting date on piping so visibly, should we not provide last inspection date on the important pipe support and spring hangers, snubbers, rigid struts and standard supports in high risk flameable or lethal catagory piping!

regards,
sam