Covers LP-Gas (propane, propylene, butanes, butylenes) systems: DOT cylinder systems (c), non-DOT storage containers (d), LP-Gas as motor fuel (e), storage of containers awaiting use or resale (f) and LP-Gas service stations (h), with basic rules (b) applying to all. It does not apply to marine and pipeline terminals, gas processing plants, refineries, non-industrial tank farms, refrigerated storage, use with oxygen (see 1910.253), utility gas plants (NFPA 59) or low-pressure systems up to one-half psi (NFPA 54). Installations that met NFPA 58 when built may continue in use unless they are a recognized hazard likely to cause death or serious harm. Basic rules (b): LP-Gas odorized to be detectable at one-fifth of the lower flammable limit; approved or listed valves, regulators and assemblies; ASME or DOT containers, with welding only per the construction code and DOT repairs by a qualified manufacturer; container nameplates with capacity, design pressure, fill level and surface area; containers and first-stage regulators outside buildings except as allowed, located per Table H-23 (for example 10 feet for 125 to 500 gallons, 25 feet for 501 to 2,000 gallons, 50 feet for 2,001 to 30,000 gallons), not stacked, weeds cleared within 10 feet, 20 feet from flammable liquid tanks and never inside their dikes; valves rated 250 psig with no cast iron; excess flow valves; piping and hose to stated schedules and pressures (hose burst at least 1,250 psig), leak tested at not less than operating pressure and never with a flame; spring-loaded relief valves sized by surface area, sealed against tampering, discharging at least 5 feet from building openings; hydrostatic relief between shutoff valves; vaporizers with flame safeguards and separation walls of 100 pounds per square foot; filling densities per Table H-27; limits on vapor over 20 psig and liquid in buildings. Transfer (b)(14): an attendant stays at the connection throughout transfer, containers filled only with owner authorization, no refilling single-trip containers, no venting to assist transfer except limited cases, truck fueling at least 10 or 25 feet from buildings, positive displacement pump discharge limited to 350 psig. Tank cars: level track, "Tank Car Connected" sign, wheels blocked, an employee in attendance throughout. Personnel doing installation, removal, operation and maintenance must be properly trained. Ignition control and Class I Group D classification per Table H-28. Cylinder systems (c): not buried, excess flow valves, valve protection able to withstand a 30-pound weight dropped 4 feet, portable heater flame failure devices, limits for use inside buildings (for example 245 pound water capacity containers and 735 pound manifolds, 20 feet separation, in buildings under construction). Non-DOT containers (d): design per Table H-31, filler pipes 10 feet from buildings, relief discharge at least 7 feet above containers over 2,000 gallons, maximum 90,000 gallons, underground cover and coating, 6-foot fence and 12-B,C extinguisher at bulk plants, water supply for 150,000 gallon installations. Motor fuel (e): lift trucks charged outdoors per NFPA 505, 250 psig valves, no more than two containers per truck, automatic shutoff valves, no unattended parking near heat. Storage awaiting use (f): 300 pounds maximum in industrial buildings, 10,000 pounds in special rooms, outdoor distances per Table H-33, 8-B,C extinguisher. Service stations (h): containers up to 30,000 gallons, dispensers 20 feet from buildings, a competent attendant for each fill, no smoking signs with 4-inch letters, engines off, 8-B,C extinguisher.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.