Stop Tap, Valve Box & Inspection Cover Locator

Model 500: a locator specifically designed for the water industry and used by water companies

Detecting metal objects down to a maximum of 1m (39.4"), model 500 has a number of key features over other industrial metal detectors


  • one piece construction
  • ignores litter
  • light weight (only 1.1kg)
  • easy to use (only one control knob)
  • strong signal
  • able to work next to parked cars
  • locates covers up to 95cm
  • Operates from just 4 AA size batteries
  • No training necessary

Typical Object Type Approximate Detection Ranges

Stop Top Box 50cm (19”)
Fire Hydrant Cover 87cm (34”)
Inspection Cover 95cm (37”)

Model 520: Deep Cover Metal Detector

The 520 Metal Detector is very high powered for greater depth detection. Originally designed to locate water mains, pipes and cables the The 520 is also the perfect choice for location work in cluttered areas and at depths where other metal detectors simply do not work.

Deep-seeking and accurate - Can locate a 100mm (4") metal water main at 1.20m (46") and will locate valves even when the frame and cover are missing.
Unaffected by temperature changes or power lines - Model 520 is unaffected by changes in temperature and moisture and overhead power lines (where normal tracing can not be used).
Stable and reliable - Model 520 does not need constant zeroing or recalibrating and is built to last.

Clear Audio Signal - Loudspeaker with a clear audio tone. In noisy environments simply connect headphones to the socket point.
Internal Battery - no need to find replacement batteries.

Metal covers of control valve boxes are often lost during resurfacing of roadways or from nearby excavation work, making the location of the valves difficult for traditional metal detectors. If the nearest line valve to a burst main cannot be easily located then the next accessible valve has to be isolated, potentially affecting an additional two or three hundred households and creating a lot more work.

Main Features

  • High quality taut-band moving-coil meter shows signal strength and battery state
  • Loudspeaker with clear audio tone.
  • Socket for headphones (for noisy situations).
  • Loudspeaker/mute switch.
  • Long handled search coil.
  • Leather carrying case for control unit.
  • Built-in high quality rechargeable batteries.
  • Supplied battery charger for 110v AC or 220-240v AC


Approximate detection ranges

80mm (3") cast iron main
100mm (4") cast iron main
100mm (4") valve only
150mm (6") cast iron main
Washout/Fire hydrant cover
140mm (5½") diameter plate

100cm (39")
118cm (46")
83cm (33")
127cm (50")
121cm (47")
70cm (27")

Saves valuable time and disruption to customers
Able to minimise customer inconvenience by locating the isolating valve, even when the cover is missing.

Deep-seeking and accurate
Can locate a 100mm (4”) water main at 118cm (46”) and unlike traditional metal detectors will locate valves even when the frame and cover are missing.

Unaffected by temperature changes or power lines
Model 520 water main locator is unaffected by changes in temperature and moisture as well as its proximity to overhead power lines where normal tracing can not be used.
Stable and reliable.

Unlike `hobby` metal detectors Model 520 does not need constant zeroing or recalibrating. It is designed as a professional tool and is built to last.

Designed with the needs of the operator in mind
The control unit comes in a leather case with shoulder strap, which allows a natural viewing angle when reading the display. A clear audio warning tone or headphones free the operator from constantly watching the display

Ergonomic design
The earch head has a long handle for natural operating position and the unit is balanced so that it can held without tiring.

Backed-up by full product support service
All our water instruments have a full one year guarantee on parts and labour.

Highly directional detection field
Unaffected by nearby interfering signals. Simple metal detectors or water valve box detectors / locators simply cannot match this instrument in action.

Unique false signal filtering technology
Eliminates time wasting false signals from cigarette packets and similar metallic litter.

Deep detection range
Can detect inspection covers down to nearly 1 metre, even when obscured by foil packets and similar items buried a few centimetres down, above the cover. The locator will ignore the litter but will detect the inspection cover.