Process Pipework explained

pipework

Food and beverage manufacturing can involve the transfer of materials and liquids through a purposely-designed pipe system, aka process pipework. This should be cleaned and tested regularly, to:

  • Reduce product build up and blockages that decrease flow and lessen productivity
  • Detect corrosion, cracking or leaks in the pipes
  • Clean lime-scale
  • Meet manufacturing regulations and pass inspection, and
  • Ensure hygiene

Hired pumps supplied by a specialist are used during cleaning and testing. As the pipework is decommissioned during these processes the client is essentially non-operational (costing them revenue in lost profits); therefore the main issue for them is time. Ensuring that the task is completed successfully but quickly, and with minimum disruption, is key. Utilising the services of a pump rental expert experienced in this particular type of application helps enormously to achieve that.

Typical process pipework users

Just some of the types of manufacturing / industry that require process pipework include:

  • Dairy
  • All beverages, from squash and fizzy drinks to alcopops, whisky and water
  • Any food commodity that takes and mixes different ingredients that need to be moved around (in-between storage or in mixing vessels and tanks, e.g.), and, at some manufacturing plants, to transport the finished product to the final bottling or packaging area

Process pipework can also be required to transport hazardous materials, such as flammable hydrocarbons, toxic chemicals, or thermally reactive chemicals (at a chemical and refinery facility). In such environments, accidents inevitably occur.

In January 2004, the U.S. Chemical Safety and Hazard Investigation Board (CSB) investigated an explosion and fire at a facility in Texas. A peroxide/alcohol mixture was heated above its thermal decomposition temperature. The mixture was trapped in a low point along a 900-foot-long, 6-inch process pipe. The resulting explosion and fire seriously injured two employees. Plant personnel incorrectly believed that a nitrogen gas purge preceding the steam purge had removed all liquid from the pipe.

Process pipework specifics

The type and size of process pipework installed at a manufacturing plant will depend upon the material(s) being transported there, and the specific requirements of the liquid or ingredient that could actually flow through the pipes 24/7, all-year-round – apart from during pipework servicing and maintenance.

The process pipework could be stainless steel, lined with anti-corrosion materials, or simply a plastic pipe used for the transfer of an inert liquid, such as water. The diameter of the pipework will also differ, as will the complexity of the system, depending upon the manufacturing plant’s size and the involvedness of processing there.

Water-based cleaning is best

The client will be eager to keep process pipework operational as much as possible, with cleaning and maintenance down-time being kept to an absolute minimum. Water-based cleaning is by far the most relied upon process, being the cheapest, fastest and most effective method. That said, finding ways to accelerate cleaning further (while not affecting system efficiency) is being constantly looked at: various ways of cleaning pipework are being developed, such as ultrasonic imaging technology to identify corrosion or areas with significant build up. Air cleaning with minimal water is also being tested.

About the pumped water cleaning method

This is where the option to use portable pumps can prove highly convenient and cost-effective for clients; with testing and cleaning only being necessary at certain intervals throughout the year, investing in a permanent pumping system is nonsensical.

One large UK pump hire company worked with Brewchem to clean the process pipework at Buxton Water (producers of Buxton® Natural Mineral Water). Brewchem carry out the design, fabrication and installation of process pipework systems and associated plant for companies across the country. Cleaning the process pipework for Buxton Water involved:

  1. A pipe cleaning company delivering clean water to the site using articulated tankers.
  2. A clean water high pressure pump (provided by a pump hire specialist*) being used to first flush the water through the pipework, before actual cleaning.
  3. The pipe cleaning company then using an independent device, called a ‘pipeline pig’ (or ‘pipe pig’), to help clean the system thoroughly, and perform other tasks.

* A pumping expert will know about correct flow rates and water pressure, to ensure a thorough flush-through takes place without damaging a process pipework system.

More about pipe pigs

Due to the pressure of the liquid inside a pipe, a pipe pig can move freely through process pipework. There are specific pipe pigs for different jobs, such as inspecting corrosion, cleaning lime-scale, removing product build up, or crack or leak detection. All will require a specific amount of pressure and flow rate, depending upon the pipework itself and the type of pipe pig used.

A final word (about hydrostatic testing)

Hydrostatic testing involves water or another type of liquid, such as oil, being pumped into a tank (or other type of large vessel or liquid-holding unit/system) to test its pressure tolerance. The liquid is usually coloured with dye, for heightened visibility.

A rented pump is used to fill the tank until a test pressure level is reached. At that point, tank handling experts will check to see if the tank (whether newly manufactured or used) has any leaks, or if the internal structure is corroded, flawed or worn. This is known as checking a tank’s integrity. The hydrostatic test will also check to see if the tank ‘pressure bursts’.

A well-established pump specialist will have worked with a number of food manufacturers and their contractors, and will understand the different testing requirements of process pipework. They’ll also be experienced in providing hydrostatic testing services. So, where a client uses both a process pipework system and storage tanks at their facility, they won’t have to source system cleaning and hydrostatic testing expertise from two different providers – the specialist can advise upon and handle both jobs, saving the client money.

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