The Appendix J provision is only for small shop fabricated tanks. These provisions may not be used for the larger field-erected tanks. Are you conducting a hydrotest also or are you trying to substitute the pnuematic test for the hydrotest?
Tanks built to Appendix F can be pneumatically tested (while filled with liquid) as a part of the hydrotest. Floors and some roofs are typically tested with a vacuum box. Repads can be pneumatically tested. API-650 includes provisions that, with approval of the purchaser, penetrating-oil testing can be substituted for hydrotesting where water isn't available. I think API-12D includes provision for pneumatically testing tanks. Does one of these answer your question?
