Pig Signallers


This is an omni trigger operated unit. The principle feature consists of a magnetic link between two packs of rare earth magnets.

The trigger is omni-directional and may also be actuated upwards as a plunger. When the trigger is actuated (very low torque is required) a follower mechanically moves a magnet pack axially in the signaller body. The magnet pack is strongly linked to a second magnet pack and shaft which move axially within an unpressurised housing.

The movement of the shaft operates a visual, manual reset flag or activates a limit-switch (auto-reset), giving a positive indication that a pig or sphere has passed the signaller.

The flag or switch may be set such that it can be seen from any given direction.

Models availableDirect mountedFlange mountedValve mounted flange/direct
1. ElectricalEWEFEV-F / EV-W
2. MechanicalMWMFMV-F / MV-W
3. CombinedCWCFCV-F / CV-W



  • Suitable for any pipe size from 3" norminal;
  • Standard pressure range up to ANSI 900;
  • Higher pressure range available to specification;
  • NACE conformity;
  • Principle feature of operation by rare earth magnets;
  • Low-torque trigger;
  • Internal moving parts stainless steel;
  • All seals standard metric;
  • 'O' rings viton unless otherwise specified.

Product guide

  • The pig-sig. range is specifically designed, in concept and detail, to overcome the limitations of earlier signalling methods;
  • The sensor probe (trigger) is omni-directional: it can neither damage pigs or spheres nor be damaged by their passage;
  • Trigger has 100% free movement; therefore positioning of welding boss is unrestricted;
  • Indicator flag is rotatable in 90 increments to obtain the most visible vantage;
  • Available for use with foam and polly pigs;
  • Positive action indicator flag is instantly reset;
  • No moving seals, thus minimizing the possibility of product leakage from the pipeline;
  • Simple concept - maintenance free;
  • Easily adapted for existing welding connections to replace worn or defective units.

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