‘Pig Signaller’, ‘Pig Detector’ & ‘Pig Passage Indicator’ is bi-directional intrusive devices attached to the pipeline via a Weld-on Base or Flange and available up to ANSI 2500 (6170 psi). A trigger protrudes slightly into the line enough to come into contact with a pig or sphere but has little to no effect on flow. All models are set with line-specific trigger lengths but can be easily set to suit varying thicknesses of a pipeline of any diameter on site. Upon the pig or sphere striking the trigger the Hi-T signals the user the pig has crossed the point via a mechanically operated signal flag, electrical auto-resetting switch, or both.

Pig Detector units are classified into two styles, those models which are not designed for removal while the line is under pressure and those models which are fitted with an integral valve and suitable for controlled removal when the pipeline cannot be de-pressurized. For these valve models, a simple jacking bracket tool is available for this purpose. Consisting of a safety screw mechanism and bridging clamps it facilitates the removal and re-installation of the Pig Alert from the line under pressure in a matter of minutes.


The proven pivotless tumbler mechanism and laminated trigger blades provide the necessary depth of penetration into the pipeline to give a positive signal in all circumstances with negligible effect on the flow.
The trigger has also been extensively tested with on line inspection pigs and the Hi-T signaler carries full British Gas approval.


All models can be easily set to suit the varying thickness of pipeline of any diameter without being limited to preset lengths of mounting bases. The trigger carrier mechanism can be extended or retracted into the main body by simply releasing a locking screw and rotating the carrier to achieve the correct length to suit the mounting base and pipe thickness. The maximum adjustment is 1″ (25mm).


All Pig Detector can be supplied for retrofitting to replace unworkable pig and sphere signalers. All that is needed to substitute for any manufacturers existing type and model of scraper passage indicator is a simple adapter that can be supplied with the Pigalert. Details of the make and model of the base must be specified.


All models are bi-directional available with either mechanically operated signal flags or electrical auto-resetting switches or mechanical and electrical signals in combination.


The internal moving parts of all models together with the associated pressure housings are made from stainless steel to B.S. 316 816 or the equivalent cast material.