摘要:
Integrated flow control backflow preventer valve (“IFCBPV”) for new and existing wet- and dry-barrel fire hydrants, with barrel drain assemblies for dry-barrel hydrants, and hydrants equipped with such IFCBPVs, are presented. An exemplary IFCBPV can have a retaining screen comprising equidistant concave radial spokes intersecting at a central ring structure, a freely suspended check ball, and a lower ball seat with a seal. The upper surface of the retaining screen can be affixed to the hydrant's axial shaft, and can thus be used to open and close the hydrant via the ball. Alternatively, the retaining screen can be fixed and the axial shaft provided with a cup on its bottom that mates with the freely suspended ball that is caged between the retaining screen and the ball seat. An exemplary barrel drain assembly can comprise a spring-loaded piston, or alternatively, a check ball design as in the main barrel.
摘要:
A heating system for dwellings or other enclosures includes a furnace in which a burner is isolated from a hot air or water system, and receives substantially all of its combustion air from outside the enclosure and preheated. A heat exchanger is provided between exhaust gases from the burner of the furnace and the combustion air.
摘要:
A construction is described for insertion to the invert of a sewer conduit system or the like in order to determine the rate of flow in that system. The device includes a flow tube apparatus which may be permanently inserted to the sewer system and which converts open channel flow of the system into full pipe flow for greater accuracy in measurement of the flow rate. Also included in the construction is a metering apparatus which may be lowered into the flow tube apparatus when a measurement is desired.
摘要:
A heating system for dwellings or other enclosures includes a furnace in which a burner is isolated from a hot air or water system, and receives substantially all of its combustion air from outside the enclosure and preheated. A heat exchanger is provided between exhaust gases from the burner of the furnace and the combustion air.