NITROGEN STORAGE TANK PERMITTING, INSTALLATION & COMMISSIONING IN MASSACHUSETTS
On two of our current projects, SPEC has been involved in the permitting of liquid nitrogen storage tanks with their associated vaporizers, piping and controls. We have facilitated the installation of numerous cryogenic tank gas supply systems over the past 30 years, but the permit requirement for bulk storage tanks was a new experience.
In Massachusetts, the permit threshold is given by 527CMR: Board of Fire Regulations, Chapter 1.04. Table 1.12.8.37(c). A storage permit is required for nonflammable cryogenic liquids when the volume is 60 gallons or greater inside a building and 500 gallons or greater outside a building. With the fire departments we have dealt with, to date there is no specific cryogenic storage application form. The permits we have applied for and been issued utilized existing Flammable and Combustibles storage permit applications, annotated by the applicant, for the cryogenic liquid stored and its volume in gallons. As such, the application is extremely simple and, at $50 in the City of Woburn, inexpensive as well. The permit was issued approximately 3 weeks after our application was filed and needs to be renewed annually.
Along with the storage permit, the building permit for the needed concrete foundation, fencing, piping and electrical work received a greater level of scrutiny than was our past experience. This seemed to be driven by the local fire department being the AHJ for the cryogenic liquid storage permit and a heightened awareness of the requirements of NFPA 55 and ANSI/CGA P-18. Demonstrating code compliance will require a stamped site plan showing the property lines and the location of nearby building exits and operable windows. NFPA 55 Chapter 8, governs cryogenic fluids and the full list of required setback distances is given in table 8.7.2. Specific requirements for physical protection of the stationary storage tank are called for by section 8.13.2.3.1. This in turn references section 4.11 where detailed specifications are given for minimum 4” diameter x 3’ tall, concrete filled bollards, located 4’ on center, embedded a minimum of 3’ deep in 15” diameter footings. The bollards must be located not less than 5’ away from the liquid storage tank.
Once the facility construction is complete and the nitrogen system installed by the gas supply company, a site inspection by the fire department is required prior to the storage tank being filled. Most departments need only 2-3 days’ notice to schedule an inspection, and once the site inspector approves the installation, the system can be filled and put into service.
