Hygienic (Sanitary) Pig Maintenance

How to Check Your Pig and When to Change It.

Every day, HPS pigs are in active use in thousands of factories, industrial plants, manufacturing and processing facilities. What’s more, they’re used with a massive variety of products. These range from fine wines, luxurious chocolate and distinguished single malt whiskies, through to pet food, household paint, toothpaste and varnish.hygienic sanitary pigs

If you have an HPS system, then whatever application or product you are processing, you have the assurance that you are using what are probably the best quality hygienic pigs available. What’s more, each pigging system is accompanied by technical manuals, product documentation and a handy ‘how to check your pig’ checklist for your maintenance team.

Long Working Life

HPS pigs are robust, long lasting, resilient, and can withstand high temperatures without degradation. Used correctly and looked after properly, they provide effective and efficient product recovery and pipeline cleaning for a long time. In fact, we guarantee that for most product recovery applications, our pigs will last for at least 30 000 metres (90 000 feet) of travel through a pipe when operating at or around ambient temperatures. That’s quite some distance!

Check Pigs Regularly

Note that only qualified maintenance technicians or engineers should carry out any form of pig inspection, checking or maintenance.

Like any industrial equipment, it is important to check the condition of HPS pigs regularly. We strongly recommend this forms part of a scheduled pigging system maintenance programme. How often your maintenance team checks the condition of the pig (or pigs) depends on a variety of factors. These include the product, environment, operating temperatures, frequency of use and the process. However, after an initial commissioning period (where pigs are checked more frequently), we recommend qualified maintenance staff undertake thorough pig inspections at least once a month.

How to Check a Pig

There are two main visual checks to assess the condition of an HPS pig. The first is to check the surface texture for wear, and the second to check the whole pig for damage.

A new pig has a textured or mottled outer layer. This texture helps ensure efficient and effective product transfer. Therefore, if the outer layer is smooth or badly worn, the pig will not be operating effectively and it is time to replace it. Because the amount of ‘acceptable’ wear varies between systems and products, if the pig surface is only showing a small amount of wear, contact the HPS spares department of your local HPS representative for advice.

It is also important to check the pig for damage. This includes gouges, grooves, deep cuts, dents, distortion, indentations or pieces missing. If you see any of these, in particular if the inner core is showing, contact HPS for replacement pigs. Before replacing the pig however, you must find out the cause of the damage, otherwise you may be significantly reducing the life span of future pigs. This includes checking your pigging system pipeline infrastructure.

When to Change Your Pig

Except under exceptional circumstances, you should change your pig when it is showing signs of wear, any signs of damage, or after it has travelled through 30 000 m (or equivalent) of pipe. To find out when it has travelled this distance, simple multiply the number of pigging runs the pig has performed as indicated by the sequence counter, by the length of pipe it travels through. Remember to note (or with some systems reset to zero) the sequence number when you change a pig.

If you wait until your system is not functioning effectively, you notice you are not recovering as much product as normal, the pig is not cleaning as thoroughly as previously, it gets stuck in the line or there is product contamination, you have left it too late!

Do Not Use Worn or Damaged Pigs

Using worn or damaged pigs will result in inefficient performance. Although this may not be immediately noticeable, it will show in lost production. Product that you could be saving will be going to waste, thus affecting yields and profits. You may also find that you’re using more water and cleaning fluids and changeover times are starting to increase.

Importantly, using worn or damaged pigs increases the risks of cross-contamination. Although HPS pigs do not include solid magnets (they have a flexible silicon-based magnetic core instead), if a sharp obstruction or similar is causing the pig damage it is potentially possible that some of material from which the pig is made could literally be torn off and get in to the product. Damaged pigs may get stuck, causing downtime.

Using a worn or damaged pig is similar to driving a car with worn or damaged tyres – everything may seem OK but could have a major problem any minute!

Further Help and Information

We provide every HPS product recovery system with full manuals and technical documentation written specifically for each system. The documentation includes operational criteria for HPS pigs, full installation and maintenance instructions.

For further information about pigging system maintenance or to order spare pigs, contact the HPS Spares Department on +44 (0) 115 968 3366 or email Spares@HPS-Pigging.com.

For help, advice or information about hygienic and sanitary pigging systems for your business, contact HPS or your local HPS representative.