- After inactivity, check for aged air hoses, loose fittings, hardened suction cups and binding joints. Do not load a workpiece before completing the recommissioning checks.
- Follow this recommissioning sequence: visual inspection → systems → safety → unloaded trial → low-load trial → return to service.
- Inspection priorities depend on the time out of service: about 1 week: air supply and dust; about 1 month: aging and lubrication; over 3 months: the complete process.
- Before returning to service, functionally test emergency stops, air-loss protection and drop prevention, and provide operator refresher training.
Before handling equipment returns to service after production changes, line modifications or standby storage, recheck its structure, pneumatic circuits, tooling and protective functions. For custom equipment, inspect each item against the tooling configuration, workpiece weight, centre of gravity and site conditions, and verify handling, retention and release in sequence.
01Why equipment must be checked before loading
Inspect equipment condition before carrying out loaded operations. Deteriorated suction-cup seals during inactivity may extend vacuum build-up time or reduce holding force; unstable pressure and circuit leaks may affect lifting, clamping and release; dust and inadequate lubrication may cause joints, arms and pins to bind. Check braking and drop-prevention functions as well, so handling does not resume with ineffective protection.
Minor fitting leaks, hardened suction-cup edges or loose stops may be difficult to detect without a load but may cause slipping, swinging, incomplete release or positioning errors under load. Complete the visual inspection, system inspection, safety confirmation, unloaded trial and low-load trial in that order before returning the equipment to service.
02Visual inspection: contamination, damage and structural deformation
First inspect for dust, oil, water marks and metal corrosion, then check the column, arm and tooling frame for deformation, impact damage or unusual scratches. Where forklifts, material carts or other equipment pass through the storage area, pay particular attention to impact marks on the base, joint housings and tooling end.
Also inspect the electrical and pneumatic control boxes, valve assemblies, guards and identification plates for completeness and damage. If there is obvious deformation, cracking or unusual impact damage, verify structural strength and installation condition before attempting a trial run.
03Mechanical checks: supports, rotation and travel limits
On column-mounted manipulators, check the column, base and anchor bolts for secure fastening, inspect the surrounding floor for cracks, and check expansion or chemical anchors for looseness. On rail-mounted or suspended equipment, also inspect track connections, suspension points, trolleys, end stops and anti-disengagement devices.
Move the joints, arm and slewing mechanism to check for binding, unusual noise, excessive clearance or abnormal movement. Confirm that limit blocks, mechanical stops and buffers are intact and effective. After prolonged inactivity, clean and lubricate dry or lightly corroded pins, bushings and bearings as specified, and check for interference throughout the motion range.
04Air supply checks: pressure, condensate and leaks
Check supply pressure, the filter-regulator setting and pressure-gauge stability against the equipment requirements. Inspect the filter bowl for accumulated water, oil and contaminants; drain or clean it and replace the filter element as its condition requires.
Inspect air hoses section by section, focusing on bends, cable carriers, fittings, moving tooling parts and rubbing points. Prolonged compression, nearby heat or ageing may harden, crack or wear through hoses. Replace hoses showing age-related leakage, bulging, flattening or surface cracks promptly; do not wrap them with tape and continue using them. Check push-in and threaded fittings for looseness and leaks, using leakage sounds, pressure decay and soapy-water testing as appropriate.
05Vacuum checks: pickup, retention and release
Vacuum-system checks must cover both suction-cup condition and holding performance. Inspect cup edges for hardening, cracking, curling and deformation, and the contact surfaces for oil, dust and indentations. Check the vacuum generator, gauge, filter and piping as well. Gauge readings should remain stable and vacuum build-up time should not increase noticeably. Include filter blockage when investigating slower pickup.
After gripping a simulated workpiece by vacuum, maintain the system state and observe whether vacuum decays too quickly. Verify any fitted air-loss protection, drop-prevention protection or low-vacuum alarm under low-risk conditions. Do not handle production workpieces while the vacuum system is abnormal, particularly rough-surfaced, heavy, off-centre or high-value workpieces.
06Tooling checks: gripping, positioning and release
For jaw-type tooling, test synchronized opening and closing and the clamping stroke. Inspect jaw pads, polyurethane pads and rubber pads for wear, hardening, debonding and embedded metal chips to identify unstable gripping and surface-scratching risks. Check pins, springs, bushings, links, guides and stops for looseness, corrosion, fracture and wear.
Test release to confirm that the workpiece disengages normally without jamming, dragging or partial release. For combined tooling, check clamping, pressure retention, release and reset item by item with the cylinders, vacuum system and mechanical interlocks, covering the complete operating sequence.
07Safety functions to verify before recommissioning
Before recommissioning, functionally test emergency stops, brakes, air-loss protection, drop prevention, low-vacuum alarms and travel limits. For equipment with balancing control, also check stopped, air-loss and low-pressure states to confirm that there is no abnormal sinking, uncontrolled slewing or sudden release.
Safety and maintenance personnel should inspect the work area together: remove obstacles, ensure the floor is not slippery, and confirm that workpiece placement suits the handling route. Do not schedule production before the safety-function checks are complete.
08Unloaded and low-load trials
Do not begin recommissioning trials at full load. First test lifting, slewing, translation, stopping, reset, tooling opening and closing, and release without a load, covering the normal working range. Check for unusual noise, vibration, binding, sluggishness, pressure fluctuations and abnormal rebound.
Once unloaded operation is normal, use a low-risk workpiece, simulated load or lighter test piece for low-load testing. Gradually complete pickup, clamping, handling, positioning and release. Check for slipping or swinging, vacuum fluctuations, difficult release and noticeably heavier operation. Resume normal loaded work gradually only after confirming that no abnormalities are present.
09Inspection priorities by time out of service
- About 1 week out of service: check supply pressure, filter condensate, tooling dust, suction-cup contamination and operating buttons. Complete an unloaded trial.
- About 1 month out of service: additionally inspect hose aging, fitting leaks, cup hardening, joint lubrication and loose stops. In dusty, oily or humid environments, focus on filters, seals and corrosion of metal parts.
- Over 3 months out of service: follow a complete recommissioning process. In addition to routine checks, inspect anchor-bolt fastening, arm-joint clearance, cylinder seals, vacuum-generator performance, tooling repeatability and drop prevention. Reassess workpiece weight, handling routes and tooling suitability if equipment has been relocated or modified, or operating conditions have changed.
10Recommissioning checklist
| Category | Inspection Details | Normal condition | Corrective Action |
|---|---|---|---|
| Appearance inspection | Dust, rust, deformation, collision marks | The surface is clean and the structure has no deformation or cracks. | Clean; stop and assess any deformation or cracks |
| Installation base | Columns, bases, anchor bolts, track connections | Reliable fastening, no looseness, no ground cracking | Re-tighten or reinforce and review the installation foundation |
| Mechanical joints | Joints, arms, slewing and translation mechanisms | Smooth movement without binding, unusual noise or excessive clearance | Clean and lubricate; inspect pins, bushings and bearings |
| Air supply system | Pressure, filter-regulator, condensate and hoses | The pressure is stable, the filter is clean, and the air hose is not damaged | Drain and clean, adjust pressure and replace aged hoses |
| Vacuum system | Suction cup, vacuum generator, vacuum gauge, filter | The vacuum is established quickly, the reading is stable, and the pressure is maintained normally. | Clean filter, replace suction cup or inspect generator |
| Tooling mechanism | Gripper jaws, pads, springs, pins, and seals | Full clamping engagement, normal return and intact pads | Replace worn parts and correct binding or leaks |
| Release mechanism | Release button, valve group, clamp release action | Smooth release, no jamming or dragging | Check the valve block, pneumatic line, spring and mechanical interference |
| Safety Function | Emergency stops, brakes, air-loss protection, drop prevention and alarms | Effective function and reliable action | Suspend recommissioning; correct faults and repeat verification |
| No-load test run | Lift, rotate, translate, stop, reset | Smooth motion without unusual noise or vibration | After identifying the cause, perform a load test |
| Low-load trial | Simulated load or low-risk workpiece testing | Stable vacuum gripping, reliable clamping, and normal release | Suspend production and recheck the system |
11Operator refresher training before return to service
Before returning to service, provide a short refresher on rated load, permitted operating range, confirmation of vacuum pickup or clamping, emergency-stop locations, abnormal-condition response and prohibited operations. Review button functions, operating pace and release sequence.
New employees, reassigned employees and those who have not used the equipment for an extended period should receive an on-site demonstration and have their understanding checked. Workshop supervisors and safety personnel should organize low-load practice so operators can refamiliarize themselves with the handling feel before resuming the normal production rate.
