Cat & Mouse – FAQs

How does the Cat & Mouse fit to the tank?

The presented level indication system is suitable for a wide range of liquids from water based effluent to strong chemicals. To ensure an enclosed system (required for hydrochloric or nitric acid for example), it is connected to the tank via a flange which has a nominal bore of 100mm (PN16). See the installation sheet. This enables the PP float to be introduced inside the tank.

The external indicator (transparent PVC tube, 63mmOD metric) in which the magnetic counterweight travels, is to be secured in position every 1.5m.

Shall I buy the “essentials” or the “complete system”?

The Essentials

We have designed the “essentials” kit for those who are simply after the core functional items of the cat and mouse system : PP float, PP string

(10m), pulleys (x2) and magnetic counterweight. This offer is likely to be more suitable for :

  • Tank manufacturers
  • Maintenance department
  • Plant installers
  • Pipe fitters
  • Anyone contacting us for advice on installation!
The Complete system

We have designed the “complete system” for those who are after all the necessary items including necessary PVC fittings and external transparent tube for the installation of the system. You then only have to make sure your tank is fitted with a NB100mm (PN16) flange, and consider the fitting of the external tube bracketing (clips for the bracketing of the external level indicator are supplied). Only PVC glue, MEK and either plastic or metal welder for the brackets are required.

The complete system includes the “essentials” and the following PVC fittings:

  • Stub flange and backing ring 100mm
  • Reducer long pattern NB100 – NB32
  • 1m of 40mm transparent pipe and one socket union
  • Reducer NB32-NB50 and one socket union in NB50
  • Required length of NB50 metric transparent pipe
  • One end cap NB50

You have the choice of two tank’s height : 2.5m and 5m. Contact us should you require greater height. We can also offer a heavy duty system.

Can I get a graduated ruler?

Yes. The graduated ruler can be prepared with the unit of your choice. Contact us to give your exact requirement.

What are the typical restrictions to consider?

First of all the material of the proposed float is polypropylene, so you need to make sure that the liquid is compatible. Stainless steel and PVC floats can also be available. Contact us.

The system is typically designed for temperature up to 60°C.

Unless placed inside a guide tube, which nominal bore has to be greater than 100mm, the float can not be placed in a tank fitted with a mixer as the string could get tangled around shaft and impeller.

The s.g. of the liquid has to be above 0.9. If this is not the case, Contact us as we may have the solution to your problem with our adaptable buoyancy stainless float!

Is the BSM501 level sensor any good?

Without a doubt, the BSM501 type level sensor is great! It provides a volt free contact, normally open and normally closed. Connection is ensured by a plug supplied with the switch. A visual indication, informs the operator at a glance of the switch position. The hysteresis is ensured mechanically by the switch itself (approx. 3 to 4cm) eliminating any “waving effect” at the surface of the liquid. The switch is attached to the external tube via a jubilee clip or a cable tie (jubilee clips are preferred and supplied with the switch). Therefore the adjustment is friendly to the operator or the commissioning engineer as this does not involve any tank entry and can be very accurate.

I am not sure how to install it…

Not a problem, Contact us and we will give you a quote to come and install the system for you anywhere in the UK, Republic of Ireland and France!

What makes


... by the range of industrial pollutions we can address : pH, heavy metals, cyanides, hexavalent chromium, BOD, "Hard" COD, Fat Oil & Grease, suspended solids, sulphates, phosphorous, nitrates, Ammonia, and anything you can think of to challenge us.

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... by picking the right technology for the right problem to provide the client with a guarantee of performance. Here are some of the processes we cover : Coagulation, Neutralisation, Flocculation, Oxidation, Reduction, Flotation, Settlement, Filter press, Screw press, Centrifuge, Ion exchange resin, Membranes technologies etc.

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