Appendix 1 The Low Tech Plant FIGURE 1. Operation of the “Low Tech” Plant Filling the treatment cylinder with preservative. Vent to atmosphere 3 way valve V3 To Vacuum pump V6 V8 V7 V4 V5 V1 V2. Treatment vessel Preservative Storage Packet of timber Vac Chest Compressor Air p ressure in Valve 3 connecting the treatment vessel to the vacuum pump is opened and the air in the packet of timber together with the treatment vessel are evacuated. The compressor is turned on. Valve V1 is opened and air pressure builds up in the top of the preservative storage vessel. Valve V2 is opened connecting the preservative storage vessel with the Treatment Vessel containing a packet of timber. Preservative is forced from the preservative storage vessel into the treatment vessel covering Emptying the treatment cylinder of preservative solution. Vent to atmosphere 3 way valve V3 To Vacuum pump V6 V8 V7 V4 V5 V1 V1 Treatment vessel Preservative Storage Packet of timber Vac Chest Compressor Air p ressure in Once preservative solution (yellow) covers the timber, V4 and V1 are closed. If it is desirable to apply pressure to the treated timber V8 is opened. Once the desired pressure or holding time has been achieved V8 is closed. V1, V5and V7 are now opened so that the pressures in the preservative storage vessel and treatment vessel equalise. Whilst the diagram illustrates that preservative enters the vacuum chest, normally during flooding of the treatment vessel is terminated once the packet of timber is covered with preservative solution. This is achieved by placing an automatic sensor above the packet of timber to sense when the pack of timber is covered. Preservative should now transfer by gravity back to the storage vessel. Flow of preservative back to the treatment vessel can be accelerated by opening V1 and V8. This pressurises the treatment cylinder. Once all preservative has been transferred back to the storage vessel, all valves should be shut and the treatment vessel door opened and the packet of timber removed. No final vacuum is applied. [...]... H2    H3    H4    H5    H6      DECAY /INSECT HAZARD  Low Decay Hazard (eg. Insect  Borer)  Termites  Above ground but subject to  weathering  Ground contact  (low value)  Ground contact (high value)  Exposed in sea water  TYPICAL COMMODITIES  Timber framing not exposed to  weather.  Timber framing in termite  infested regions  Fascia boards, weather boards,  external joinery, Glass‐house  components  . class="bi xb y8b w4 hb" alt =""