We investigate the pair production of right-handed neutrinos from the decay of an additional neutral Z' boson in the gauged B -L model. Taking into account current constraints on the Z' mass and the associated gauge coupling g1', we analyse the sensitivity of proposed experiments at the lifetime frontier, FASER 2, CODEX-b, MATHUSLA as well as a hypothetical version of the MAPP detector to a long lived heavy neutrino N originating in the decays of the Z'. We further complement this study with determining the reach of LHCb and a CMS-type detector for the high-luminosity LHC run. We demonstrate that in a backgroundfree scenario with g1'=10-3 near the current limit, FASER 2 is sensitive to the active-sterile neutrino mixing down to Vμ N≈10-4, while a reach of Vμ N≈10-5 can be obtained for CODEX-b and LHCb, in a mass regime of mN≈5 - 20 GeV and mZ'≈20 - 70 GeV . Finally, MATHUSLA can probe Vμ N≈10-7 and cover the mixing regime expected in a canonical seesaw scenario of light neutrino mass generation.