Abstract: A system and method are disclosed for shutting off the flow of liquid to a hydrant. A break away frangible activator of a valve body becomes dislodged responsive to a hydrant receiving sufficient inadvertent impact. A valve member closes in response to the impact to close off the flow of fluid to the hydrant.

Abstract: A system and method are disclosed for shutting off the flow of liquid to a hydrant. A break away frangible activator of a valve body becomes dislodged responsive to a hydrant receiving sufficient inadvertent impact. A valve member closes in response to the impact to close off the flow of fluid to the hydrant.

Abstract: A system and method are disclosed for shutting off the flow of liquid to a hydrant. A break away frangible activator of a valve body becomes dislodged responsive to a hydrant receiving sufficient inadvertent impact. A valve member closes in response to the impact to close off the flow of fluid to the hydrant.

Abstract: A system and method are disclosed for shutting off the flow of liquid to a hydrant. A break away frangible activator of a valve body becomes dislodged responsive to a hydrant receiving sufficient inadvertent impact. A valve member closes in response to the impact to close off the flow of fluid to the hydrant.

Abstract: A tractor unit system includes a tractor unit that has a travel drive gear. The travel drive gear includes a drive gear portion and at least one drive roller portion. The system also includes a guide track that has a track gear. The track gear includes a track gear portion and at least one land portion. The at least one drive roller portion and the at least one land portion are configured such that the at least one drive roller portion contacts the at least one land portion when the drive gear portion is engaged to the track gear portion. In some embodiments, a diameter of the at least one drive roller portion is equal to a pitch diameter of the drive gear portion. If the track gear portion is curved, in some embodiments a diameter of the at least one land portion equals a pitch diameter of the track gear portion. In other embodiments, if the track gear portion is straight, a dimension of the at least one land portion equals a pitch line of the track gear portion.

Abstract: A tractor unit mounting mechanism includes a clamping assembly that is configured to engage and disengage the tractor unit to a track guide. The tractor unit includes at least two pivot blocks with each pivot block including at least one rolling device and a locking mechanism. The at least one rolling device is designed to roll on a rail of the guide track. The clamping assembly is configured to operatively connect the at least one rolling device with the guide track when the tractor unit is engaged. The pivot block is configured to pivot such that the at least one rolling device can conform to a profile, e.g., a concave profile, convex profile, a straight profile, or any combination thereof, of the guide track as the tractor unit is engaging the guide track. The locking mechanism, e.g., a bushing, is configured to prevent the pivot block from pivoting once the tractor unit has engaged to the guide track.

Abstract: A tractor unit mounting mechanism includes a clamping assembly that is configured to engage and disengage a tractor unit to a guide track. The guide track includes a first rail and a second rail. The mounting assembly also includes at least one pivot block set that has a first pivot block and a second pivot block. Each of the first pivot block and the second pivot block includes a first rolling device and a second rolling device. When the tractor unit is in a disengaged position, a first distance between an outer portion of the first rail and an outer portion of the second rail is greater than a second distance between the first rolling devices of the at least one pivot block set, and the first distance is less than a third distance between the second rolling devices of the at least one pivot block set.

Abstract: Exemplary embodiments of welding track clamps are disclosed herein. These track clamps provide several new features including, without limitation, alternate methods and apparatuses for adjusting clamping force and assemblies that provide for increased clamping force for rigidity and stability of welding tracks. The invention further provides ease of use and assembly/dissassembly.