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Elmac’s Unstable Detonation Arresters (UCA Series)

The use of large capacity tanks and vessels is a common practice in a wide range of commercial and industrial enterprises.

Storage tanks hold liquids, compressed gases (gas tank) or mediums used for the short or long-term storage. Filling and emptying the tanks is accomplished through connected piping systems.

Tank protection equipment is fitted in various forms to protect against pressure, external ignition or contamination which could have detrimental effect on the products being stored or the vessel itself.

Atmospheric storage tanks are generally thin-walled and only designed to operate under low pressures. They are also primarily designed against the build-up of internal pressure and have extremely low resistance to vacuum.

Storage tanks – normal venting requirements

Changes in the liquid volume are caused by routine filling and emptying of the tank that inherently increase and decrease the vapour space

Changes in the temperature of the vapours and liquids in the tank are the result of variations in the ambient atmospheric temperatures. These fluctuations in temperature and volume also cause fluctuations in pressure.

Normal venting relief will allow the tank to breathe, preventing collapse or overpressure of the tank.

Pressure & vacuum relief valves are specifically designed to protect tanks from under or over pressurisation when correctly sized. They protect against the fluctuations in pressure associated with the general operation of a storage tank:

  • Filling
  • Emptying
  • Thermal Expansion

Elmac carry a full range of pressure only, and vacuum only relief valves, should these be required. Please get in touch with us today.

Storage tanks – the need for protection

Adequate tank protection is required to stop the catastrophic failure of a vessel.

A tank can be fitted with:

  • a high level alarm, but this might be turned off due to faulty readings
  • a pressure control system, which could be out of service
  • a pressure relief valve with a flame arrester, which may be isolated after maintenance


Without any means to vent the build-up of internal pressure, when a product is transferred into the tank, it can easily become over-pressured until the roof ruptures, throwing it to the ground. And all despite only reaching a few psi over atmospheric pressure.

  • Lowest pressure drop
  • Easy to maintain
  • No additional safety needed
  • Maximum pumping efficiency
  • Maximum safety
  • Flexibility in installation
  • Reduced maintenance frequency and downtime
  • Reduced insurance premium
  • Save £1000s in pumping costs


HEDS – High Energy Dissipation System

The UCA Series of unstable detonation flame arresters sets new performance benchmarks largely down to the fact that it comes with a High Energy Dissipation System, or HEDS for short.

HEDS increases performance levels because it:

  • attenuates the shock wave
  • dissipates heat
  • is a lighter & more efficient element
  • offers market-leading flow vs pressure drop performance
  • operates energy savings of over 30%
  • provides no restrictions on placement within piping systems

UCA Flame Arrester Benefits

  • Protects against unstable detonations, stable detonation and deflagration
  • Lower pressure drop than any detonation arrester in the market
  • Lower energy consumption
  • Removable, modular, easy-clean elements
  • No positioning restrictions
  • Reduced maintenance / down-time

It all means that by choosing an Elmac UCA detonation flame arrestor, you can look forward to:

  • Increased safety
    • Protection from unstable detonation providing highest possible level of safety
    • Reduced insurance premiums
  • Reduced running costs
    • Significant cost savings in energy consumption, maintenance and down time
  • Less environmental concern
    • Less energy consumption leading to reduced carbon footprint