The Sentinel range of filter units has been specially developed for the filtration of electroplating solutions and the range of capacities available will meet the majority of automatic and manual plating installation requirements.

Sentinel filter units are totally enclosed, provide a large filtration area, are easy to clean and maintain, and provide effective retention of activated carbon or filter aids.

The filters are designed to take plate packs and the standard units incorporate a rubber lined centrifugal pump.


Sentinel filters may be used on the majority of electroplating solutions including:

  • NICKEL - bright, semi-bright, dull
  • ZINC - cyanide, alkaline, acid, neutral
  • TIN - acid, stannate
  • COPPER - cyanide, pyrophosphate
  • CADMIUM - cyanide, acid, neutral.

For the following solutions sentinel filters fitted with special pumps can be supplied:

  • flourborate and fluoride based solutions
  • acid copper
  • acid tin (including bright solution.)
  • solutions containing free hydrochloric acid e.g. nickel chloride strike solutions.

Sentinel filters are not suitable for the filtration of chromium plating solutions.

Filtration of anodising solutions: For sulphuric acid anodising solutions standard Sentinel filter units are advised.


Sentinel fiter units are supplied in three sizes having one, two and three filter containers respectively. The filter contains are made of steel with a special quality high temperature cured rubber lining and are mounted on a sturdy tubular steel cradle. On standard units the motor-driven pump is mounted within the cradle, below the filter container. The single and double container units are fitted with castors for ease of movement, the three-container unit is provided with mountings for foundation bolts.

Filter Pack: Sentinel filter are supplied with a plate type pack as described on the reverse. Packs can easily be removed from the container for cleaning of replacement without the use of a hoist, and to simplify this operation valves are fitted to the individual containers in case of larger filter units to enable them to be drained of solution.

Centrifugal Pump: The Standard Sentinel filter units incorporate close coupled centrifugal pumps designed for filtration duties. A non-metallic/stainless steel impeller housed in a rubber lined cast iron body is used with an immersed type.

Mechanical seal. Alternatively magnetically coupled, seals monoblock pumps can also be supplied. The filter units are supplied complete with a suitable motor, mounted on the tubular frame. A valve is fitted to the pump inlet to permit the unit be isolated.

Pipework: Sentinel filters are provided with flanged inlets and outlets, permitting when required, direct connection to rigid plastic or rubber lined steel pipework. The units are supplies complete with two 3 metre (10ft.) lengths of reinforced acid resistant polypropylene hose including appropriate spigots.

Sentinel filter units can be supplied as part of comprehensice solution handling facilities incorporating features such as:

  • Transfer of solution from plating tank to storage.
  • Solution circulation for heat exchangers and low current density plating out-units.
  • Chemical make-up tanks.
  • Plating solution purification treatments.
Units with mechanical seal Sealless units
Model   NOX Single Double Triple Tynee NOX Single Double
Code No.   952302 952401 952501 952601 952201 952305 952402 952502
Overall Length mm 860 860 1145 1700 550 600 860 1145
Overall Width mm 735 735 735 840 450 450 735 735
Overall Height mm 920 1065 1065 1145 550 670 1065 1065
No. of containers nos 1 1 2 3 1 1 1 2
No. of clothes nos 8 16 32 48 8 8 16 32
No. of plates nos 9 17 34 51 9 9 17 34
Cloth area m2 0.6 1.1 2.2 3.3 0.6 0.6 1.1 2.2
Clean flow capacity Lt/hr 2250 4500 9000 13500 800 1800 4500 9000
Pack Changes Lt/hr 1125 2250 4500 9000 400 900 2250 4500
Hose bore mm 30 30 30 50 25 25 30 30
Motor hp hp 0.5 2 3 5 0.08 0.16 0.5 2
Elec. input kw 0.38 105 2.2 3.7 0.06 0.12 0.38 1.5
Nett weight kg 120 140 230 325 85 90 115 200
Gross weight kg 170 200 290 410 110 120 175 270
Case length mm 1016 1016 1320 1850 620 680 1016 1320
Case width mm 762 762 813 879 510 510 762 813
Case height mm 1067 1168 1168 1250 620 750 1168 1168
Standard Plate Type Back:

Code No. 762351/752359/752451 Sentinel filter packs are supplied with moulded plastic combined filter and spacer plates and cotton fabric filter cloths. A pack can be removed from the filter, the plates dismantled, clean cloths and papers inserted, the pack re-assembled and placed back into the filter container in approximately fifteen minutes. To reduce the time the filters is out of use for cleaning purposes, it is advisable to have a spare filter pack; this enables the changeover to be accomplished in approximately five minutes. Plate type packs are recommended where a large filter area is required and for effective retention of carbon or filter aids. The standard units are suitable for solution temperatures up to 65° C.

Order Requirements:

When ordering please give the following information:

  • Type number of Sentinel filter unit required.
  • Solution to be filtered. Plase note that the use of a single filtration unit for different types of solution is not recommended.
  • Solution temperature.
  • Power supply.
  • Details of pipework requirements and any ancillary equipment existing or required.

On permanent installations it is recommended that a wet deck area drained into the effluent system be provided with a water supply and adequate area to service the filter packs. For efficient pump operation an unrestricted flooded line to the pump is essential. In certain situations it may be necessary to locate the pump adjacent to the plating tank. We will be pleased to advise and supply pipework systems, mixing and storage tanks.

Progressive changes in design and specification may be made from time to time without prior notification.