Pig Design & Spares

At the centre of the Martec Product Recovery System the pig is propelled by compressed air, CIP Process water or even a following batch of product.  The design of the product recovery pig is critical towards acheiement of high integrity hygienic performance.

Spherical pig - no wiping edge to clean with - poor cleaning ability. Heavy internal magnet. Rotating orientation means detection never guaranteed. Cannot pass full-bore openings.

Solid pig - single leading edge - smears trapped product into sidewalls. Weak internal magnetic core - requires sensitive and expensive detectors. Can jam and become damaged by pipe imperfections.

Flexible Vane – multiple windscreen wiper action enhances removal of product from pipe walls. Tolerates pipe imperfections and 1.5 D bends.


 

RANGE OF PIGS	FDA POLYURETHANE	FDA SILICONE		DETECTABLE FDA SILICONE
Size (nominal)	Flexible Vane	Flexible Vane	Sphere	Flexible Vane	Sphere
1"/25mm			♦		♦
1½"/38mm	♦
2"/50mm	♦	♦	♦	♦	♦
2½"/62mm	♦	♦	♦	♦	♦
3"/75mm	♦	♦	♦	♦	♦
4"/100mm	♦	♦		♦
5"/125mm	♦
6"/155mm	♦
6"/164mm	♦

Size

Each pig is specific for the pipe inside diameter as they are accurately dimensioned for optimal performance.  When ordering state the Spec/Size of pipe e.g. ‘3” dairy’ or provide us with an ID dimension (e.g. 73mm). We may still be able to supply if you have sizes outside the standard range.

Material

Food grade materials are used throughout our range of pigs as defined by FDA and European standards.  However, we have different formulations depending on conditions as determined by the product the pig will be used with and whether it will be exposed to CIP temperatures/chemicals.  There is also a detectable material version for extra security. If in doubt use FDA silicone.

Style

The flexible vane pig design is the most advanced solution for all food and hygienic applications and is recommended unless it is incompatible with in situ equipment.  Incompatibility is most commonly due to old style short-length launch/receive stations, pipe routing or unconventional valves.  If you have cleanliness or cross contamination issues from use of spherical pigs we would be happy to give advice on required system changes.
 

Does pig need replacing?

Just as vehicle tyres there are wear limits for the effective working diameter of a pig.  Martec have applications where the pig can traverse 50km of pipe (typically 6 to 24 months) before this limit is reached but the numbers of bends and material in the pipe (friction) can dramatically affect this. The tell-tale signs indicating approach of a wear limit are dilution of product by process water, periodic pauses in the pig's progress or increased air pressure needed to maintain pig momentum.

At the extreme if on removal from the pipework the vanes do not return to their natural shape then the pig certainly needs replacing.  Ensure the correct material is used as continual exposure to high operating or CIP temperatures will deform and/or stiffen the wiping vanes making them ineffective.

If the pig has suffered any mechanical damage clearly it should be replaced (it would be worthwhile isolating and correcting any recurring cause of mechanical damage). 

If in any doubt we can advise.  At Martec we are always happy to receive photos as these are often the most effective way to explain in-situ concerns.