(a) Each operator shall conduct an unannounced spot check of each welder's field welds at least once each calendar year at intervals not exceeding 15 months to assess the quality of welding. Such spot checks shall include destructive or nondestructive tests of a field weld. Should an unannounced spot check of a welder identify unacceptable welds, a follow-up unannounced spot check shall be conducted within three months or as soon as possible thereafter.
(b) A field weld chosen during the unannounced spot check may be used to maintain the welder's qualification if tested and found acceptable under section 3 or 6 of API Standard 1104 (as described in section 10.3 of this Title) for welders qualified under subdivision 255.227(a) of this Part.
(c) In the case of welders qualified under subdivision 255.227(b) of this Part, the spot check must follow the test procedures set forth in Appendix 14-F of this Title.
(d) This unannounced test may be used to satisfy the requirement to have a weld tested during the six months preceding welding as required in section 255.229(c) or (d)(2) of this Part.