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Star International
Product code: 00950005

Star One Shot BWT

A liquid blend of alkaline mineral salts, sequestering agents, scale and corrosion inhibitors, oxygen scavenger and sludge conditioner.

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Star One Shot Boiler Water Treatment (BWT) is a liquid blend of alkaline mineral salts, sequestering agents, scale and corrosion inhibitors, oxygen scavenger and sludge conditioner.


  • Correct precipitation of hardness salts in conjunction with phosphate.
  • Neutralisation of acid conditions.
  • Avoidance of caustic corrosion.
  • Control of magnesium and calcium salts.


Suitable for use with:

  • Auxiliary boilers.
  • Waste heat boilers economisers.
  • Package boilers.
  • Smoke & water tube boilers steam/steam generators.
  • Up to 30 bar pressure.


  • Complete ‘one shot’ liquid conditioning treatment.
  • Boiler kept at peak level efficiency.
  • Heating surfaces kept clean, so optimum conditions exist.
  • Promotes protective films to prevent boiler steel corrosion.
  • Dispersant action suspends sludge and sediment particles for efficient blowdown.
  • Reduced maintenance.
  • Oxygen scavenging for increased protection.

The alkalinity ‘balance’ is extremely important for efficient water treatment. Star One Shot provides this whilst avoiding excessive pH levels which could cause embrittlement and corrosion of boiler components.

Hardness control

Star One Shot provides a phosphate reserve to effectively react with and precipitate the hardness salts introduced with the feed water. The formation of insulating scale on hot metal surfaces is prevented as the salts produced will not adhere and so optimum heat transfer efficiency is maintained.

The stable phosphate compounds used in Star One Shot will maintain their efficiency throughout the boiler’s normal operating temperature range. Where low temperatures can cause low phosphate levels, this is avoided.

Sludge conditioning

Boiler sludge can most easily be removed by blow down if it is free flowing. Star One Shot will ensure this by preventing the scale from coalescing to form large crystals or adhering to metal surfaces. The resulting sludge is free flowing & will easily be removed by blow down when required.

Oxygen control

Oxygen scavenging becomes more vital with an increase in boiler pressure. The oxygen scavenger will effectively react with dissolved oxygen even at lower temperatures.


  • 25 ltrs (00950005)

Directions for use

Star One Shot is best fed into the boiler feed line by means of a metering pump. Gravity fed systems should be dosed by means of a flowmeter and dosing drum.

Do not slug dose.

Initial dose

Untreated system 5 litres / 1000 litres distilled feed water resulting in 100ppm P alkalinity.

Additional dosing of Star One Shot is required to bring the P alkalinity level to a midpoint of 200ppm. Blow down is dependent on alkalinity and chloride levels. If alkalinity drops below 100ppm, increase the dosage by 20%; if alkalinity exceeds 200ppm, reduce dose by 20%.

In general, the ranges are: 100-300ppm P alkalinity. 200ppm chloride maximum.

Please read the Material Safety Data Sheet before using this product for detailed information on safety and health.

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