Detailed procedures must be in place for the control of hot bolting and must be observed. For further information, see EEMUA Information Sheet No. 17 Rev. 1, dated May 1999.
5.12 Restrictions on Hot and Odd Bolting a)
Marginal time savings during shutdowns on disjointing should not be considered sufficient incentive for Hot Bolting operations.
b)
A formal engineering review of the proposed Hot Bolting operation must be carried out to establish that there are no unacceptably high external loads and bending moments acting on the joint. The review should consider, as a minimum, the following: i) ii) iii) iv) v) vi)
Contents of the line or eqiupment. Design and operating pressures and temperatures. Possible upset conditions. Position and functionality of piping supports. Position and type of expansion bellows fitted. Maintenance history of the joint.
c)
Flanges should have a minimum of 8 bolts.
d)
Hot Bolting shall not be considered when the operating pressure exceeds 60% of that specified in ASME/ANSI B16.5, Annex G, Table G for any given flange rating.
e)
A thorough inspection of the flange assembly should be conducted to verify the integrity of the flange and fasteners. These operations should not be allowed if bolts and nuts show signs of corrosion, necking or are suspected of having cracks.
03000785, May 2000
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