Zygo 7702

Description

Technical Specifications

Functional Features

• 3/4 inch square drive — accepts standard 3/4 inch sockets and impact sockets for direct bolt engagement
• Zero-backlash hydraulic motor — eliminates mechanical slack, ensures immediate torque transfer to the bolt
• Dual-scale analog torque gauge — reads simultaneously in ft-lbs and Nm, visible from operator position
• Adjustable reaction arm — 3 position quick-change arm allows use in tight flange configurations where a full-length reaction bar cannot fit
• Overload protection — internal pressure relief valve set at 11,000 psi (760 bar) prevents damage from excessive pump pressure
• 360-degree swivel hydraulic coupling — allows hose connection from any angle, eliminates hose kinking during operation
• Trigger-operated control valve — single-hand operation with pull-to-advance, release-to-retract control
• Safety lock-off pin — prevents accidental trigger actuation during transport and storage
• Calibrated torque output — factory calibrated to ±3% accuracy, calibration certificate included with each unit
• Compact head profile — 5.5 inch head height fits in flange bolt circles as small as 4.5 inch diameter
• Quick socket change — detent ball socket retention allows fast socket swapping without wrenches
• Built-in pressure gauge on tool — 0 to 15,000 psi gauge on the wrench head for real-time pressure monitoring
• Corrosion-resistant finish — phosphate coating with black oxide finish on all external steel surfaces
• Ergonomic trigger handle — rubber-grip trigger requires < 5 lbs pull force for activation

Performance Parameters

Material Composition

Structural Features

• Forged alloy steel head — single-piece forged construction eliminates weld failures under high torque loads
• Radial piston hydraulic motor — compact design fits within the 5.5 inch head height envelope
• 3/4 inch square drive with detent ball retention — positive socket lock prevents socket ejection under load
• Dual-scale torque gauge mounted on top of head — readable from standing operator position without bending
• 3-position adjustable reaction arm — arm pivots to 3 fixed angles (0°, 45°, 90°) for confined-space access
• 360-degree swivel hydraulic inlet — rotating coupling allows hose to enter from any direction
• Integrated pressure gauge on head — 0 to 15,000 psi gauge provides real-time pressure feedback at the tool
• Trigger-operated directional control valve — pull trigger to advance (apply torque), release to retract (reset)
• Safety lock-off pin on trigger — steel pin inserted through trigger hole prevents accidental actuation during transport
• Overload relief valve internal to motor — set at 11,000 psi, protects motor and hose from overpressure
• Quick-change reaction arm pins — spring-loaded pins allow arm removal and repositioning in under 30 seconds
• Ergonomic contoured grip on head — rubber overmold grip area allows two-hand control during high-torque operation
• Drain plug on motor housing — 1/4 inch NPT drain allows hydraulic fluid sampling and motor flushing
• Calibration adjustment screw on gauge — accessible from outside the housing for field recalibration without disassembly

Working Principle

The Kings 7702 operates as a hydraulic motor-driven ratcheting torque wrench. When the operator pulls the trigger handle, the hydraulic control valve opens, allowing pressurized hydraulic fluid (up to 10,000 psi) from the external pump to enter the zero-backlash radial piston motor inside the wrench head. The hydraulic pressure acts on the pistons within the motor stator, causing the rotor to rotate. The rotor is directly connected to the square drive anvil, which transfers the rotational force to the socket engaged on the bolt head or nut. The motor rotates in a unidirectional ratcheting motion — advancing the bolt with each trigger pull and automatically resetting (retracting) when the trigger is released, ready for the next pull. The torque gauge measures the reaction force between the wrench head and the reaction arm (which pushes against an adjacent bolt or reaction point). As torque increases, the gauge needle rises proportionally. The operator monitors the gauge and releases the trigger when the target torque value is reached. The overload relief valve inside the motor opens at 11,000 psi, diverting fluid back to the reservoir and preventing damage if the operator over-pressurizes the system. The hydraulic hose returns fluid to the pump reservoir for recirculation. The 3/4 inch square drive provides a mechanically locked connection to the socket, ensuring zero slippage during torque application.

Advantages and Highlights

• Zero-backlash hydraulic motor — eliminates mechanical lost motion, delivers ±1% torque repeatability
• ±3% torque accuracy — factory calibrated, meets ASME PCC-1 bolt tensioning accuracy requirements
• 2,150 ft-lbs maximum torque — handles Grade 8 bolts up to 1-1/8 inch in a single tool
• 3-position reaction arm — fits in bolt circles as small as 4.5 inch diameter, eliminates need for multiple tools
• Dual-scale gauge (ft-lbs / Nm) — readable from standing position, no need to bend over
• Trigger-operated single-hand control — operator holds reaction arm with one hand, pulls trigger with the other
• Quick socket change — detent ball retention allows socket swap in < 10 seconds without wrenches
• Integrated pressure gauge on tool — real-time pressure monitoring at the point of use, no separate gauge needed
• Compact 5.5 inch head height — fits in standard flange bolt patterns where impact wrenches cannot reach
• Overload protection at 11,000 psi — internal relief valve protects tool, hose, and operator from overpressure
• ASME PCC-1 compliant — calibrated and certified for use in critical bolted joint assembly per industry standard
• Forged alloy steel construction — 4140 steel head rated for > 1,000,000 cycles at rated torque
• 360-degree swivel inlet — hose connects from any angle, eliminates kinking in confined spaces
• Corrosion-resistant black oxide finish — withstands harsh industrial environments including offshore and chemical plants

Applicable Industries

Model Series Comparison (Kings 7700 Series)

Installation Requirements

• Hydraulic Pump Required: Use a Kings model 7801 or equivalent hydraulic pump rated for 10,000 psi, 1 GPM minimum flow rate
• Hydraulic Fluid: Fill system with ISO VG 46 mineral hydraulic oil or Kings branded hydraulic fluid; do not use automatic transmission fluid (ATF)
• Hose Connection: Connect 3/8 inch ID, 10,000 psi rated hose to the 360-degree swivel fitting on the wrench head; tighten to 30 ft-lbs (41 Nm)
• Reaction Arm Setup: Position the reaction arm against an adjacent bolt, nut, or solid reaction point; ensure the arm is fully seated in one of the 3 locked positions
• Socket Selection: Use impact-rated 6-point sockets in 3/4 inch drive; do not use 12-point sockets (they strip under high torque)
• Bolt Preparation: Ensure bolt threads are clean, dry, and lubricated per ASME PCC-1 Table F-1; use molybdenum disulfide or nickel-based anti-seize
• Gauge Zero Check: Before each use, verify the torque gauge reads zero with no load on the drive; adjust calibration screw if necessary
• Pressure Check: Verify pump pressure gauge reads 0 psi before connecting hose to wrench; bleed air from hose by triggering wrench with hose disconnected until fluid flows
• Operating Pressure: Set pump pressure to achieve desired torque; refer to the torque-pressure conversion chart on the tool nameplate
• Working Clearance: Ensure minimum 6 inches (152 mm) clearance around the wrench head during operation
• Grounding: Ground the hydraulic pump to the facility earth ground bus using 12 AWG minimum green/yellow wire

Usage Precautions and Notes

• Never exceed 10,000 psi operating pressure — overpressure causes motor seal failure, hose rupture, and serious injury
• Never operate the wrench without the reaction arm installed — without a reaction point, the wrench head will spin freely and cannot apply torque
• Never use 12-point sockets — 12-point sockets round off under high torque; use 6-point impact sockets only
• Never apply torque to a bolt that is not properly lubricated — dry threads cause false torque readings and bolt galling
• Never operate the trigger with the socket off the bolt — free-running the motor damages the ratchet mechanism
• Never bypass the internal overload relief valve — the valve is set at 11,000 psi for operator safety; do not adjust or remove it
• Never use the wrench as a breaker bar — it is designed for controlled hydraulic torque application only
• Check hydraulic fluid level before each use — low fluid causes cavitation, motor damage, and inaccurate torque
• Replace hydraulic hose every 12 months or immediately if any swelling, cracking, or abrasion is observed
• Calibrate the torque gauge annually — send to Kings authorized service center or use a calibrated torque tester per ISO 6789
• Do not operate in temperatures below -20°F (-29°C) — hydraulic fluid viscosity increases, motor stalls, and seals crack
• Do not store the wrench with the trigger pulled — this keeps the control valve open and drains hydraulic fluid from the motor
• Insert the safety lock-off pin during transport — prevents accidental trigger actuation that could cause injury
• Wear safety glasses and steel-toed boots during all torque wrenching operations — bolt failure releases stored energy explosively
• Do not stand in line with the reaction arm — if the reaction point fails, the arm swings with full torque force
• Vent the hydraulic system before disconnecting hoses — residual pressure remains in the hose and motor after pump shutoff
• All torque wrenching operations must follow ASME PCC-1 Appendix F — use the correct bolt lubricant, torque sequence, and tightening pattern
• All installation and operation must be performed by trained personnel per ASME PCC-1 and OSHA 1910.147 (Lockout/Tagout) requirements