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Overhaul & Repair - Workshop
Breather Valves/Vents

The refurbishing of valves is performed in our dedicated and fully equipped workshop, enabling us to calibrate and certify valves.

Our workshop is based in the North West of England and has the capabilities of overhauling all types & sizes of tank protection equipment. 

Every valve that leaves the workshop will have been rigorously tested to all the recognised standards 

Workshop capabilities 

  • Valves can either be sent to our workshop or we can collect direct from site

  • We strip items to their component parts, inspect and clean

  • We can also shot/bead blast and re-paint were required. 

  • Equipment is reassembled using all new soft spares and any other spares needed to return the valve to a good working condition. If additional spares are needed the customer is always made aware and photos are provided to show damage or the reasons behind the recommended change.

  • Once reassembled items are tested for example with a Breather Valves/Vents, weight packages are checked and verified for the required setting and then placed on our calibrated test rig (ISO 28300/API2000 specification) and the leakage rates are recorded in accordance with ISO 28300/API2000.

  • All performance figures are recorded on a test certificate and a detailed maintenance report is issued for the equipment.





"How do they work ?"

Low Pressure and Vacuum Relief Valves/Breather Valves/Conservation Vents/Tank Vents


Low Pressure and Vacuum Relief Vents (or sometimes referred to as Breather Valves, Conservation Vents or Tank Vents) are designed to protect atmospheric storage tanks from over pressurisation or excessive vacuum and to reduce the evaporation of the tank contents to atmosphere.


Over pressure or vacuum can occur in a number of circumstances.

  • Displacement i.e. the filling and emptying of an atmospheric storage tank. 

  • Thermal events

  • Fire conditions

  • Other events such as equipment failure



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"Why is it essential that Vents should be regularly serviced & maintained ?"

Why is it essential that Vents should be regularly serviced and maintained?


  • Diaphragm failures. Low Pressure and Vacuum Relief Vents use a pallet and diaphragm sealing arrangement if the diaphragm should become damaged then the valve will no longer seal correctly and cause the tank contents to leak out into the atmosphere. This can result in expensive losses of product and the possibility of causing environmental pollution.


  • Mechanical failures. It is essential for the correct operation of Low Pressure and Vacuum Relief Valves that all moving parts should be free and move as required. It is possible that over a period of time tank product or other debris may build up inside the valve and prevent this happening. This can lead to over pressurisation or a build up of excessive vacuum in the tank. The resulting effect being a rupture or collapse of the tank resulting in serious financial implications.