Abstract: A metallic tank having an insulated interior is disclosed which exhibits unique features to enable the welding of the tank sections together without damage to the insulation. The insulating lining is installed in the multi-piece metallic tank prior to the welding of the tank sections together. A heat shield is provided between the weld area and the insulating liner to prevent damage to the nonmetallic liner during the welding process. The method of assembly allows the economical and rapid fabrication of lined metallic tanks without fear of damaging the lining material. Also, an indirect fired water heater which has a tube heat exchanger in the lined metal tank with the heat shield. The inlet and exit lines of the heat exchanger pass through a bottom plate of the tank. The tank, in such case, contains potable water which is heated by contact with the heat exchanger located within the vessel. Hot boiler water passes through the heat exchanger to heat the water in the vessel.

Abstract: An air vent device for automatically venting entrapped air from hot water heating and chilled water cooling systems. The device can vent a large volume of air in a relatively short time by using a large vent opening, controlled by a pilot valve operated diaphragm venting valve. The pilot valve, actuated by a spring and connected to a float, permits air pressure within the device to pass to the rear of the diaphragm valve to maintain it in a closed position during normal operation of the system. When the float drops to a predetermined position the float weight overcomes the spring force and the pilot valve vents the rear side of the diaphragm valve to atmosphere, allowing it to open, thereby venting the air collected in the device to atmosphere.

Abstract: A metallic tank having an insulated interior is disclosed which exhibits unique features to enable the welding of the tank sections together without damage to the insulation. The insulating lining is installed in the multi-piece metallic tank prior to the welding of the tank sections together. A heat shield is provided between the weld area and the insulating liner to prevent damage to the liner during the welding process. The method of assembly allows the economical and rapid fabrication of lined metallic tanks without fear of damaging the lining material.

Abstract: A priorly used three layer insulation covering for conductors forming a drop wire for connecting aerial distribution cables to a subscriber's premises is replaced with a single layer insulation of a plasticized polyvinyl chloride composition.It has been found that the temperature of preheat of the conductors must fall with a critical range to control the adhesion of the composition to the conductors to be within a desired range of values. The adhesion of the composition to the conductors is important from the standpoint of the manner of installation and of strippability. The adhesion must be sufficient to facilitate support of the drop wire by a clamp customarily attached to the subscriber's premises. However, the adhesion must not be excessively high in that the forces required to strip the insulation from the conductors may damage the surfaces of the conductor.