| 摘要 |
A fire hydrant having a unitized bonnet configuration or assembly which includes a bonnet member, operating mechanism, external driving attachment and lubricant reservoir and which may be installed and removed from the hydrant barrel without the loss of lubricant from the lubricant reservoir therein or without the major disassembly of parts. Additionally, the unitized bonnet assembly is provided with a stop nut member which may be adjustably secured to the end of the valve stem to compensate for small variations in barrel lengths and/or valve stem lengths. The stop nut member is carried within the lubricant reservoir of the bonnet member and is at all times sealed from water in the hydrant and, thus, it may be made of a non-corrosive resistant material such as ductile iron or steel which is less expensive than corrosive resistant material such as brass, bronze or stainless steel. The adjustable connection between the stop nut member and the end of the valve stem is likewise protected from exposure to the water system by being fully contained in the lubricant reservoir system and thus the joint between the two is not subject to corrosion. The stop nut member which reciprocates upon rotation of the operating nut assumes the torsional loads rather than the valve stem.
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