• Case Study

St Eval Candle Company reduces its chemical waste to a minimum by using WMFTS peristaltic pumps

Efficiency and accuracy of pumps helps candlemaker in its sustainability success and to double production

  • St. Eval Candle Company uses a range of peristaltic pumps from WMFTS for dosing dyes and fragrances
  • Using dispensing and dosing pumps from WMFTS have resulted in less chemical waste for St. Eval
  • Pumps enable consistent accuracy in dosing fragrances and dyes in manufacturing scented candles

St. Eval Candle Company is reducing its chemical waste to a minimum and has doubled production after switching to Watson-Marlow Fluid Technology Solutions (WMFTS) pumps and fluid path components.

St. Eval produces millions of scented candles per year from its facility in Cornwall, England, and in 2021 was recognised for its commitment and accomplishments in sustainability with a Queen’s Award for Enterprise in Sustainable Development and B Corp certification.

WMFTS peristaltic pumps are helping the candlemaker in its sustainability success, avoiding waste and gaining efficiencies by using:

  • Two 630 Watson-Marlow series process pumps for pumping the environmentally friendly solvent MMB, a carrier fluid that is then decanted into 250 mL bottles, for its diffuser line
  • A Flexicon 520Di dispensing pump during the accurate dosing of dyes and fragrances, with no spillage
  • Four 313 OEM pumps in the moulding room for accurate dye dosing into the candles; the highly repeatable nature allows for reliable consistency



A 630 Watson-Marlow series process pump is used to transfer the environmentally friendly solvent MMB, a carrier fluid that is then decanted into 250 mL bottles

James Trethewey, Operations Manager at St. Eval, says using WMFTS pumps has increased accuracy of dosing and decreased downtime during the manufacture of high-quality candles at St. Eval.

He said: “The peristaltic pumps lend themselves to accurate dosing and no spillage.

“When we are dosing, because you have the backturn on the pump, you don’t get spilling, and you always get the same dose. When the dye and fragrance is being mixed in with the wax, the candles all come out the same colour and the same percentage of fragrance. 

If it’s under-fragranced, the customer won’t be very happy and it may burn differently. Using these peristaltic pumps, we know the entire batch is consistent and it’s repeatable.

James Trethewey, Operations Manager at St. Eval

“We are able to ensure we get the same quantity of doses, which maintains consistency in our candles. We have to get it right because these are luxury products that must meet ours and our customers exacting standards.

“In our moulding line we are dosing what we need, we are not overproducing, and the waste is kept to an absolute minimum. It allows us to dose what we want, make what we want, and there is no minimum batch size.

“Previously we weren’t even using a pump, we were just using jugs and mixing up a large batch of fragranced wax and pouring it in by hand. Watson-Marlow pumps have allowed us to become more efficient. It’s a much cleaner and quicker turnaround, and less downtime.

“We have been able to double our capacity from 350 to over 750 moulded candles per day. We were always struggling to keep up with demand but after doubling capacity it’s not such a concern and the system is easily scalable to meet future production demands.”

St. Eval Candle Company also uses Pumpsil platinum-cured silicone tubing from WMFTS, following advice from WMFTS’ post-sales support team.

James Trethewey added: “The dyes were staining the tubing and we had initially selected the wrong tubing. Watson-Marlow’s sales representative came to us and advised us to move to a different type of tubing and the feedback from the factory floor has been very good since. The support has been great, but we don’t really have to rely on it because the pumps have really been fit-and-forget.”


With chemical dosing, there is the opportunity to make a significant saving when using Watson-Marlow pumps compared to other pumps.

Toby Coker, Industrial Sector Specialist at WMFTS, said: “Operators at St. Eval Candle Company now have more time. Rather than spending an hour taking apart a pump, it takes two minutes to change the tubing on the 520Di. St. Eval was using PureWeld tubing, but we advised them to switch to Pumpsil tubing which offers more than twice the lifetime and can be used up to 80°C. This has meant a reduction in tubing, less ingredients being wasted or spoilt and less downtime at St. Eval’s factory, allowing them to focus on more value adding activity and creating even better products more efficiently.

“Watson-Marlow pumps also maintain the accuracy with changing duty pressures. As the inlet tank empties, the suction pressure drops, which can cause some competitor pumps flowrates to change to what was calibrated. The 520Di in use for example will continue to dose what it is saying it is dosing even as the tank runs near empty, which frees time up for money making activity without worrying about recalibration or compromise in quality.”


Sustainability has been at the heart of everything St. Eval does since it was founded in 1993. St. Eval produces its own sustainable energy via wind (since 2011), solar and biomass, which generates enough energy to power the entire factory and so reduces the company’s carbon footprint and impact on the environment.

After increasing the efficiency of its processes, St. Eval has recently scaled up its operations with the opening of a new factory site and the company is on the journey to become net zero.

Ian Greaves, CEO at St. Eval, said: “We are immensely proud of The Queen’s Award and we were one of only 17 to be awarded it that year. It’s prestigious and underlines our credentials when it comes to sustainability.

“From our point of view, we have gone from using measuring jugs to using Watson-Marlow pumps and it’s now done more efficiently, more accurately. It was driven by wanting to save on waste, but also to save on costs. The fragrances are our most expensive raw ingredient and we weren’t measuring it properly. We needed a pump to dispense it ready for production and in production we use it as well.

“We would hope to get 40-50,000 candles produced a day including tea lights and we produce millions per year now. It’s gone up hugely in recent years. With our new factory building, we now have more capacity and can think about exporting more.”

520Di pumps combine industrial power and durability with unrivalled precision, pumping up to 3.5 L/min and achieving pressures up to 2 bar. The pump is capable of dispensing 50 mL in two seconds with ±0.5% accuracy.


A Flexicon 520Di dispensing pump is used for the accurate dosing of dyes and fragrances, with no spillage at St Eval

630 flows between 0.001 to 19 L/min for handling valuable and delicate fluids without contamination to safely dose, meter and transfer colours, fragrances, flavours and additives.

313 pumps can accurately dose low flowrates of valuable fluids such as dyes or fragrances and can change tubing in seconds. This allows for rapid change of production line from one type of candle in this instance to a different colour and scent.

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