Dairy Pipe Lines (DPL) has gained an enviable reputation during the past 50 years for manufacturing hygienic valves, fittings and pipework for the food processing sector. We not only provide customers with quality, reliable products, but also offer expert advice to help you achieve high performance integrated process solutions.

Talk to us on 01799 611 062

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We appreciate that poor hygienic design of food process equipment and inferior build quality can affect the quality and microbiological safety of your product. All surfaces in contact with the food must be cleanable, since equipment which is difficult to clean will require more aggressive chemicals and longer cleaning cycles, resulting in higher costs, lost production time and increased effluent.

Hygienic and aseptic conditions are achieved by a variety of procedures ranging from manual strip down and cleaning of component parts to Clean In Place (CIP). For a CIP system to clean effectively the fluids must be at the correct temperature, velocity and pressure to ensure product debris is dislodged.

DPL’s hygienic Diamond valve design meets mechanical, process and microbiological requirements. Materials used in the construction of food processing equipment must be inert to both the product and cleaning chemicals whilst also being corrosion resistant and nontoxic, which is why DPL manufactures from AISI-304, 316 and 316L stainless steel. In addition, the elastomers utilized in all our valves and fittings are food grade and, where possible, the compression is controlled to prevent damage to the rubber or extrusion into the product zone, which would otherwise adversely affect cleanability.

Operational reliability and the trouble free service provided by our process equipment results from the correct selection of high quality specialized lubricants. To fulfill international food processing safety requirements we use USDA authorized ‘food grade’ lubricants. The use of unspecified lubricants can seriously affect valve performance due to possible elastomer distortion and swelling and this is particularly important in the case of EPDM elastomer types as these are extremely sensitive to contact with unsuitable lubricants.

Surface roughness can also have a significant influence on cleanability. In general, the greater the surface roughness, the longer the cleaning time required. Therefore we ensure that all surfaces in contact with food have a maximum surface roughness value of Ra < 1.0 µm, while exterior surfaces have a surface roughness value of Ra < 1.6 µm.

The exterior and interior of all food contact equipment must be self-draining and easily cleanable, with the geometry of design, especially valve design, ensuring that liquid exchange in all areas is in contact with product. DPL’s Diamond valves therefore ensure that no gas pockets remain in the valve when liquid flows through and that it is possible to drain the valve completely in at least one installation position without the need for dismantling. Furthermore, our designs also ensure there are no threads, pits, crevices or sharp edges in contact with the product.

It is important that the correct valve and fittings are specified for any given food application and the DPL team can assist in equipment selection by supplying technical data and offering advice on valves and fitting types. In addition to complying with the pressure and temperature ratings, valves and fittings must be suitable for use with the product type, the cleaning methods and cleaning media as well as comply with site standards.

Full in house design support and manufacturing facilities combined with DPL’s experience in the production of food handling equipment enable us to produce bespoke fabrications such as valve manifolds and flow-plates. These fabrications are assembled under controlled factory conditions and can be supplied fully tested to exact customer specification – self-draining, without dead legs and with all internal welds removed. Numerous Blue Chip companies rely on DPL’s project management capabilities in the development of integrated process control systems. Working in partnership with you, we can advise on everything from simple product assembly to complex turnkey plants requiring market research, feasibility studies, technical proposals, product supply, installation and on-site inspection.

Our expertise in the food processing sector also extends to drawing up specifications to customer requirements and all this is backed by DPL’s enviable after sales service, which includes technical advice and maintenance support, to keep your product line performing.




A major manufacturer of data centre cooling units had received a request from one of its customers to supply its coolant distribution units (CDUs) with stainless steel pipework instead of the traditional brass or copper.


So began a four-year journey where SFL assisted its client in the design, manufacture and assembly of the world’s first stainless steel coolant distribution unit.
SFL’s initial input into the project was to help in the design of the stainless steel pipework that would be installed in the CDU. Working as an extension of its client’s engineering team, SFL helped create a series of 2D CAD drawings and 3D models.

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One of the challenges SFL faced was how to fit the new pipework into the existing space, given that stainless steel isn’t as malleable as brass or copper. Through its meticulous and methodical approach, the team successfully arrived at the first version of the CDU pipework that fitted perfectly into the same footprint.
SFL’s next task was to manufacture the set of pipework for the prototype unit, ensuring the kit was manufactured to the highest possible standard. SFL then assisted in the assembly and successful fitting of the pipework into the initial unit.

The unit was then shipped off to a major trade exhibition in the USA to demonstrate the first stainless steel CDU for high performance computing and enterprise data centres. Following the initial blueprint of the prototype design, SFL helped its client fix a number of bugs and resolve a few issues in order to create the optimum design. Once everyone was happy with the final result, the team was then in a position to embark on full-scale manufacture.


Switching from brass to stainless steel offers a marked increase in quality and purity that had never been available in this market before. For example, stainless steel pipework in CDUs means improved performance, as the coolant fluid flows more efficiently through stainless steel pipes, compared to brass or copper. Another advantage is lower maintenance costs as the coolant fluid doesn’t need to be filtered or changed as frequently. A further benefit is that stainless steel is resistant to both corrosion and leaks.


After the unit was unveiled at the exhibition, orders flowed in from around the world and SFL was asked to manufacture 50 kits, destined for end customers located in Australia, Japan and the United States.

Andrew Sharp, Manufacturing Manager at SFL and part of the team who worked on the CDU project, said: “As well as becoming part of our client’s design engineering team, working on the design concepts, we also helped with the ongoing manufacture and assembly of the pipework units. We even became part of their purchasing department, buying the various components we needed in order to build our stainless steel kits. This puts us in a strong position to help other manufacturers of large data centre cooling systems who are looking to benefit from the advantages of stainless steel pipework in their units.”


  • Design acumen: measured approach, coupled with in-depth experience, when helping with the design stage of the project.

  • Prototype skill: ensured the first pipework kit was manufactured to the highest possible standard for the exhibition and was also fit for purpose.

  • Problem solvers and trouble shooters: worked alongside the client to help with all the changes required to make the unit operate at optimum efficiency and work rate.

  • Full scale manufacturing ability: set up a bespoke manufacturing cell to ensure manufacture of two kits each month, to supply market demand.

  • Dedicated account manager: daily one-to-one contact with the client, working across time zones, to provide a high level of personal service, ensuring all project issues were overcome and all deadlines met.

  • Industry knowledge: extensive understanding of HVAC/data centre cooling requirements and deadlines, to supply the growing market in hygienic stainless steel HVAC/data centre cooling systems.