D.C. Mun. Regs. tit. 12, r. 12-E1013
Insert a new Section 1013 in the Mechanical Code to read as follows:
Access for inspection. Each unfired pressure vessel shall be installed so that it is available for complete external inspection of shell and heads and shall be located so that, wherever possible, there will be not less than 12 inches (305 mm) between the vessel and any floor, wall, ceiling or other obstruction. There shall be no piping or other obstructions to prevent proper access. Any manhole or inspection opening shall be located so that it is readily accessible. All stamping and longitudinal welded or riveted joints shall be located in a position so as to be readily visible to the inspector. Where necessary to install a vessel underground, it shall be enclosed in a concrete or brick pit with a removable cover so that inspection of the entire shell and heads of the vessel can be performed.
Structural supports. Each unfired pressure vessel shall be supported by masonry or structural supports of sufficient strength and rigidity to safely support the vessel and its contents. Provisions shall be made to reduce vibration in both the vessel and its connecting piping.
Piping and connections. All piping and connections to an unfired pressure vessel shall be supported in a substantial and safe manner so that there is no strain placed upon the vessel. Provision shall be made for expansion, contraction and drainage.
Protection. Each unfired pressure vessel shall be painted with two coats of approved paint, so that it is protected from rust and corrosion. It shall not be in contact with any corrosive material or moisture.
Drip pipe. Each unfired pressure vessel shall have a bottom drip pipe fitted with a valve or cock in direct connection with the lowest space practicable. The minimum size of pipe and fittings shall be 3/4 inch (19 mm) except for tanks 20 inches (508 mm) in diameter or less, in which the minimum size of the pipe a nd fittings shall be 1/4 inch (6.4 mm). If a plug cock is used, the plug shall be held in place with a guard or gland. Globe valves and cocks shall not be used.
Pressure gauge. Each unfired pressure vessel shall have a pressure gauge connected in a manner that the gauge cannot be shut off from the vessel, except by a cock with a "tee" or lever handle, which shall be placed on the pipe near the gauge. Connections to gauges shall be placed on the pipe near the gauge. Connections to gauges shall be made of non- ferrous pipe and fittings from the tank to the gauge. Tubing shall not be used. The dial of the gauge shall be graduated to not less than 1.5 times the maximum pressures allowed for the vessel. A 1/4 inch (6.4 mm) test gauge connection shall be provided for attaching the inspector's test gauge.
D.C. Mun. Regs. tit. 12, r. 12-E1013