Hydraulic Hose Failure, Floor Spill, and a Storm Drain
The hydraulic power unit for a 100-tonne press holds 200 L of ISO VG 46 mineral oil. During the night shift the suction hose between the tank and the pump starts weeping; by morning about 15 L has dripped onto the machine base, the floor, and into the drip tray. The floor slopes toward a 100 mm drain that the maintenance planner says goes to the storm canal. A used spill kit is on the shelf: the absorbent bag is half empty, the socks are oil-soaked, and the container has no label. Two technicians are assigned. One wants to wash the oil into the drain with a hose and then mop; the other wants to finish the hose change first because production has been down for six hours. There is no lockout padlock on the pump motor isolator, and the press has a 60 L accumulator. Available PPE: nitrile gloves, safety glasses, rubber boots, and one face shield. There is no bunding under the oil drums in the warehouse.
1. Identify the unsafe conditions and state the controls and isolation sequence required before the suction hose is opened. Explain the stored-energy risks specific to this press.
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Unsafe conditions
- No lockout on the motor isolator; the pump can be started remotely or by a fault reset.
- A 60 L accumulator holds pressure after the pump stops: fatal injection risk and a source of sudden movement.
- Oil on the floor and machine base: slip hazard, plus a fire load near hot surfaces.
- An open, unlabeled spill kit that is not fit for a 15 L spill.
- No bunding: a 200 L tank can gravity-drain through an open suction line.
- Barricade the area and put up a spill-in-progress sign.
- Isolate the pump motor at the local isolator, apply a personal lock and tag, and try to start to confirm isolation.
- Stop the pump, then blow down the accumulator through its bleed valve and confirm 0 bar on the gauge; keep the bleed open. Never open a line on a press with a charged accumulator.
- Isolate the suction line: close the tank valve if fitted and plug or cap the hose end. If not, drain the tank below the suction level into a clean container first. A 200 L reservoir will empty fast through a suction line.
- Check for hot surfaces before resting hands or tools on the pump; allow cooling.
- PPE: nitrile gloves, safety glasses, rubber boots, face shield where a spray is possible.
- Catch residual oil in a drip tray, then replace the hose, seals, and clamps to specification, refill with filtered oil, and leak-test at low pressure before running.
2. State the correct spill response, including the drain, and explain how the recovered oil, absorbent, and rags must be handled. Explain why washing to the drain is unacceptable.
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Spill response
- Stop the source first. Fix or plug the leak before adding absorbent, otherwise you keep chasing new oil.
- Protect the drain immediately. Cover the 100 mm drain with a drain seal or sandbag before doing anything else on the floor. Washing with a hose turns a contained 15 L floor spill into an environmental release into the storm canal, which is a reportable pollution incident and may attract a notice of violation. Storm drains go to waterways, not to treatment.
- Contain and absorb. Socks around the spill, then absorbent on the oil. A half-empty kit is not enough for 15 L; restock or use sand or vermiculite.
- Clean the floor with an oil-emulsifying cleaner and mop up. Mop water goes to the oily-water separator, never to the storm drain.
- Recovered oil goes into a labeled, lidded container for recycling or re-refining.
- Used absorbent, oil-soaked rags, contaminated gloves, and the old oil-soaked socks are hazardous waste. Metal lidded container, labeled with the contents and date, kept away from ignition, because oil-soaked rags can self-heat.
- Do not mix with general refuse and do not burn. Dispose through a DENR-accredited hauler with a waste manifest, as required for hazardous waste under RA 6969.
- If any oil reached the drain, notify the environmental officer and record the incident, quantity, and action taken.
3. List the 5S and preventive actions you would put in place so that this spill and the delayed hose change do not recur, and explain the root cause each action addresses.
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5S actions
- Seiri (sort): remove the unlabeled open container and expired absorbent from the shelf.
- Seiton (set in order): a shadow board for a full spill kit at each oil-handling point, with drain seals stored next to each drain and marked on the floor plan.
- Seiso (shine): drip pans under the HPU and a clean-floor check at shift end; the drip tray gets cleaned, not just inspected.
- Seiketsu (standardise): a one-page hose-change standard covering lockout, accumulator blow-down, suction isolation, drain protection, and waste segregation; a labeled waste container at the point of use.
- Shitsuke (sustain): weekly audit of kit completeness and drain protection, with the result posted.
- Root cause of the leak: an aged or abraded hose with no inspection interval. Add hoses to the PM route: date-tag on installation, visual check for abrasion, cracking, and swelling, and replacement on a fixed interval rather than on failure.
- Root cause of the delay: no spares. Keep the suction hose and seal kit in stock with a minimum level.
- Root cause of the drain risk: no bunding and no drain protection. Provide bunding for the drums and the HPU, and mark the drain as a protected point.
- Train both technicians on the standard and record the training, so the next night shift does not repeat it.