Line Pull Limiting: A manually adjusted pressure control valve on the control panel is used to preset and maintain pump pressure limits. This valve causes the pump to shift to a neutral flow condition at the preset pressure thus preventing excessive line pull. This design feature is very important for preventing accidents and damage to conductors or structures.

Puller: Any device that is used to pull a conductor in during stringing operations. Pullers are designed in many configurations for varying uses, including Drum Pullers, Bull wheel Pullers, Pilot Line Pullers, Reel Pullers, etc. Pullers are usually equipped with their own engines but may be powered from an external source such as a truck tool circuit or other hydraulic power supply.

Tensioner: Equipment that is used to maintain hold back tension on the conductor or conductors in power line tension stringing operations. Commonly used tensioners designs are a drum tensioners and multi-groove "bull wheel" tensioners. Drum tensioners can be used when tension requirements are low. Multi-groove wheel tensioners are used when high tension is required.

Puller/Tensioner: Engine powered machines that are used to both pull and tension. Specially designed hydrostatic power systems with "mooring control provide smooth precise control. This type of equipment provides the most positive control of conductors under tension.

Friction Brake Tensioning Basic tensioning system uses ventilated brake rotors with hand wheel operated calipers. Friction brake systems work well for lighter duty conductor tensioning. The sprocket and chain drive brake system lowers caliper clamping forces to reduce "stiction" that causes surging on direct connected brakes.

Hydraulic Tensioning Hydraulic oil is pumped over a a variable flow compensated relief valve system to produce retarding forces. The heat generated from the pressure drop is removed by means of oil coolers. Coolers are sized according to performance rating of the equipment and the expected ambient temperature under which they are to operate.

Hydrostatic Tensioning/Pulling Engine driven hydrostatic pumps provides constant braking and pulling torque. Powered systems offer the best control for reconductoring near energized circuits. Less manual labor is required for with these systems.

Demand Pay Out. Term used with underground cable pulling machines. Cable is pulled from machine as required when a light force is applied.